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ARISTOTLE'S PSYCHOLOGY

A TREATISE ON THE PRINCIPLE OF LIFE

ARISTOTLITS PSYCHOLOCY

A TREATISE ON THE PRINCIPLE OF LIFE

(DE ANIMA AND PARVA NATURALIA,

TRANSLATED WITH INTRODUCTION AND NOTES

BY

AVILLIAM ALEXANDER HAMMOND, M.A., Ph.D.

ASSISTANT-PROFESSOR OK ANCIENT AND MEDIAEVAL PHILOSOPHY IN
CORNELL UNIVERSITY

SWAN SONNENSCHEIN & CO.<-tTM,

" ,.o^e of Med/aei,

NEW YORK : THE MACMILIyAlSr 00;-^
1902 . .

«?/

^. ^

/^C?"

LidKARY

xc^^^

GLASGOW : PRINTKD AT THE UNIVERSITT TRKSS
BY ROBERT MACLEHOsE AN1> CO.

%0
WILLIAM WATSON GOODWIN',

ELIOT PROFESSOR OF GREEK LITERATURE, EMERITUH,

IN HARVARD UNIVERSITY,

MY FIRST TEACHER IN THE WRITINGS OF ARISTOTLE,

THIS BOOK IS GRATEFULLY INSCRIBED.

PREFACE.

The comparative inaccessibility of the Parva naturalia
(they exist in English only in Taylor's paraphrase) has
induced me to prepare an English version of these im-
portant tractates. To this I have added a translation of
the De anima, in order that English readers might have in
a single volume a practically complete account of Aris-
totle's psychological theories. Such a work seemed to me
to be all the more necessary at the present time in view
of the need of available primary sources for historical
research in philosophy and psychology. An adequate
history of psychology has not as yet been written.

The translation of Aristotle's works, owing to their
crabbed Greek, their puzzling lacunae and breviloquence, —
oftentimes they are almost unintelligible jottings intended,
perhaps, for lecture-notes or for later elaboration which
they never received, — has at no time been regarded by
scholars as an easy or attractive task. It is only their
immense historical significance and the intrinsic value of />
their content that could induce one now -a- days to set ^ y^
hand to the work. The De anima and Parva naturalia * '^ '^ f^"

cannot be said to be in a more satisfactory condition

vii

Vlll PREFACE

than the other writings of Aristotle. I have, however,
attempted no speculative reconstruction, such as has been
applied with some success to the Politics by Barth^lemy-
St.-Hilaire and Susemihl. The attempt has not been very
fortunate in the case of Essen's restoration of the De
anima, and, so far as 1 know, his predecessors in the
same endeavour have not been more successful. Growing
distrust of the radical treatment of texts seems to me a
hopeful mark of critical scholarship. My translation is
based on the text of the late Wilhelm Biehl (Teubner
series), whose emendations I have constantly compared
with the Berlin edition, and with whose conservative
judgment I have generally found myself in accord. Where
I have deviated from his text, I have stated my reading
in a foot-note. In 1897 I made a careful examination of
Codex E (Parisiensis Regius 1853), the best of the MSS.
for the texts here translated, but as Biehl collated this
Codex in the same year and published his Parva natur-
alia the year following, my work was rendered unneces-
sary. In any case, I was not interested primarily in
textual questions, excepting in so far as the establishment
of the text was ancillary to the establishment of doctrine.
I have aimed, therefore, to avoid the accumulation of notes
of a purely scholastic kind, which in the present volume
could only be marks of a diligent pedantry, and while I
have neglected no source of information and assistance
amongst ancient or modern commentators, I have rigidly
excluded all such matter as had no real interest for the
doctrinal exposition of the treatises in hand, or for the
history of science.

PREFAf^K IX

M. Rodier's text of the De aniiiia with translation and
notes (2 vols., Paris, 19()()) is a notabl(3 product of Freii(!li
scholarship, in which the widely scattered materials of
interpretation have been brou<(ht together and utilized with
sincrular industry and insight. M. Kodier's volumes have
been prepared with a bias of interest different from that
with which my own work is written, concerned, as they
are, largely with questions of text, of philological criticism,
and of the literary aspects of interpretation. They do
not include the Parva naturalia. The aim of the present
translation and introduction is rather to make easily acces-
sible to English scholars the scientific content of these
Aristotelian treatises, and thereby to facilitate inquiry into
the history of philosophical and psychological ideas. For
this reason my work does not duplicate the much wider
and more ambitious investigations of M. Rodier, to whose
scholarly labour I wish to pay my warmest tribute.

I desire further to record here my grateful acknowledg-
ment of various and valuable help from my colleagues,
Professors Bennett, Creighton, and Titchener. Professor
Titchener has read the proof-sheets of the entire volume,
and to him I am especially indebted for many suggestions
and criticisms.

Cornell University, Ithaca, N.Y.,
JicIt/ 29th, 1902.

CONTENTS.

INTRODUCTION.

f'AOK

I. The Soul and Life xv

II. The Faculties of the Soul xxvi

III. Nutrition and Reproduction xxix

IV. Sensation xxxv

V. The Common or Central Sense 1

VI. Imagination and Memory Ivi

VII. Practical Reason and Will Ixiv

VIII. Creative Reason Ixxi

DE ANIMA.

Book I. History of Psychological Theories —

Chap. i. Methods of investigation, separability of the soul,

relation of soul to body ----- i

ii. History of theories, theory of Empedocles, theory

of Democritus, theory of Anaxagoras - - 10

iii. The soul and motion, pre- Aristotelian theories - 18

iv. The soul a harmony, the soul and the body, the

monadic theory - 26

V. The soul and the elements, the soul and its parts,

divisibility of the soul 32

Book II. Faculties of the Soul —

Chap. i. The notion of substance, definition of the soul - 42

< ii. Animate and inanimate, the principle of life, the

soul and body 48

iii. Various meanings of soul ----- 54

xi

XU CONTENTS

PAGE

Chap. iv. Soul and final cause, the soul and nutrition,

principle of nutrition 57

V. Potential and actual, sensation and thought - - 64

vi. Sense-qualities ------- 69

vii. Vision and its medium 71

viii. Sound and its medium, definition of voice, vocal

utterance -------- 75

ix. The sense of smell 82

X. The sense of taste 85

xi. The sense of touch, the medium of touch - - 88

xii. Relation of sense-organ to stimulus, media of

sensation - - - 93

Book III. Sensation, Imagination, and Thought —

Chap. i. Tlie ' common sensibles ' 95

ii. Sense-perception, the ' common sense ' - - - 99

iii. Imagination, imagination and truth, imagination

and light -------- 105

iv. Theory of reason, abstract thought - - - 112

V. Active and passive reason - - - - - 117

vi. Thought and truth 119

vii. Thought and images, thought and its object- - 122

viii. Ideas and images 126

ix. Powers of the soul, reason and desire - - - 128

X. Psychology and conduct, function of desire - - 132

xi. The moving principle ------ 136

xii. Nutrition and sensation, sensation and well-being 138

xiii. Sense of touch 142

PARVA NATURALIA.

I. On Sensation and the Sensible —

Chap. i. Purpose of sensation, importance of hearing- - 145

ii. The organs of sense, theories of vision - - - 150

iii. The diaphanous, theory of colours, colour and

mixture -------- 157

conti«:nts xiii

PAOK

Chap. iv. Nature of tlavours, flavour and moisture, HCUHe of

touch 164

V. Nature of smell, function of smell, smell an<I

respiration, smell and nutrition - - - 171
vi. Sense and magnitude, medium of sensation - - 180

vii. Fusion of sensations, co-ordinate sensations, simul-
taneity, limits of perception - - - - 186

II. On Memory and Recollection —

Chap. i. Memory and time, memory a picture, memory and

phantasm - - - - - - - -195

ii. Association of ideas, processes of memory, recollec-
tion - - 203

III. On Sleeping and Waking —

Chap. i. Sleep and sensation, sleep and nutrition - - 213

ii. The central sense, form and matter, movements

in sleep 218

iii. Animal heat and sleep, food and sleep, the blood

and sleep 224

IV. On Dreams —

Chap. i. Dreams and illusion 231

ii. After-images, the eye and the mirror, illusion - 235

iii. Movement in dreams, imagination in dreams,

dreamless sleep- ...--. 240

V. On Prophecy in Sleep —

Chap. i. Prophetic dreams - - 247

ii. Power of prevision, interpretation of dreams - 251

VI. On Longevity and Shortness of Life —

Chap. i. The tenure of life ------. 256

ii. Causes of destruction ------ 258

iii. The perishable and imperishable - - - - 260

iv. Length of life in plants and animals - - - 262

V. Causes of long life ------ 264

vi. Comparative longevity ------ 267

XIV CONTENTS

PAOR

VII. On Youth and Old Age, and on Life and Death —

Chap. i. Life and Sensation 270

ii. Unity of the life-principle 273

iii. Development of life --..-. 276

iv. Congenital heat 279

V. Extinction and exhaustion 281

vi. Regulation of animal heat 284

VIII. On Respiration —

Chap. i. Purpose of respiration 286

ii. Aquatic animals ------- 288

iii. Lungs and gills - 290

iv. Theory of Democritus, heat and respiration - - 293

V. Plato's theory of circular movement - . . 296

vi. Pythagorean theory, respiration and nutrition - 298

vii. Theory of Empedocles regarding respiration - 299

viii. Animal heat, regulative function of respiration - 302

ix. Control of temperature, respiration of insects - 304

X. Function of lungs and gills ----- 307

xi. The w^indpipe and epiglottis - . . . 309

xii. Respiration of whales and dolphins - - - 311

xiii. Lungs and the supply of blood - - - - 313

xiv. A theory of Empedocles, effect of environment - 315

XV. Physiology of heat-regulation - - - - 318

xvi. Position of heart and gills - - - - 319

xvii. Birth and death 321

xviii. Causes of death ------- 324

xix. Inhalation and exhalation ----- 325

XX. Movements of the heart 326

xxi. Contraction and expansion of lungs, conditions of

life, natural history and medicine, - - - 328

Bibliography 331

INTRODUCTION.

I.

The Soul and Life.

Aristotle's theories regarding the structure and functions
of the 'soul' are found chiefly in the De Anima^
and the tractates collectively known as the Parva
Naturalia.^ These works belong to that part of the
coi'pus which deals with what Aristotle understands
by Physics, i.e. the world of corporeal substances, sub-
stances subject to motion and rest. Mathematical bodies,
not being subject to motion, are excluded. Soul is
ascribed to all bodies whose principle of motion is
inherent in their own nature. In other words, it is to all
organic bodies that Aristotle applies the term ; to him the
word ' soul ' is synonymous with the word ' life.' Accord-
ingly, the higher phenomena of mental life are included
among the vital activities. Aristotle, therefore, regards
Psychology from the point of view of Biology.

The philosopher of Stagira is known chiefly through his
works on Logic, Metaphysics, Ethics, and Politics. It
was mainly through these disciplines that he dominated
the intellectual development of the western world down to
the era of modern science ; and yet his writings on Physics

^ See note, Translation, p, 1. ^See note, Translation, p. 145.

XV

.if'.-'u*--'

9

XVI INTRODUCTION

occupy more space (taking as a standard the Berlin edition,
which contains, it is true, some spurious treatises) than all
the other treatises put together. Suidas, indeed, gave him
the title of the " Secretary of Nature," while Dante, who
was conversant with the speculative or practical side of
his philosophy, called him " the master of those that know." ^
The studies of Aristotle appear to have been concerned
chiefly with the phenomena of nature, whose processes it
was the primary function of his philosophy to explain.

The thing which most astonished Athenaeus (one of the
most learned Greeks of the Ptolemaic era) in his reading of
Aristotle's works, was the Stagirite's wonderful knowledge
of animal life. He says in the Deipnosophists : " Aristotle,
my dear Democritus, about whom the sages incessantly
talk and whose accuracy they constantly praise, is a marvel
to me. I should like to know from what Proteus or
Nereus of the deep sea he learned what fish do, how they
sleep, how they live. For he has told us in his writings
all about these things, so that he has become, in the words
of the comic poet, ' a wonder to fools.' " "^

In contrast with this trivial, popular conception of
Aristotle's work, I quote here Aristotle's own words touch-
ing his attitude towards the various spheres of scientific
inquiry, words very significant for their singular catho-
licity. " By way of introduction we observe that
some members of the universe are ungenerated, im-
perishable, and eternal, while others are subject to
generation and decay. The former are excellent

^11 maestro di color che sanno. Inferno^ iv. 131.
"^ Deipiw^ophistae, Bk. viii., cliap 47.

THE SOUL AND LIKK XVll

beyond coinpan; and divine, but are loss aocc^Hsibh; to
kiiowledtre. Thti evidence that niit^ht throw li^ht on them
and on the probleni.s which we long to solve respectint^
them, is furniHhod but .scantily by sensation, wliereas
respectintij perisliable plants and animals we have abun-
dant information, living as we do in the midst of them,
and ample data may be collected concerning all their
dirterent varieties if only we are willing to take sufficient
pains. Both departments, however, have their special
charm. The scanty conceptions to which we can attain
of celestial things give us, from their excellence, more
pleasure than all our knowledge of the world in which
we live ; just as a half glimpse of persons whom we love
is more delightful than a leisurely view of other things,
whatever their number and dimensions. On the other
hand, in certitude and in completeness our knowledge of
terrestrial things has the advantage. Moreover, their
greater nearness and affinity to us balance somewhat the
loftier interest of the heavenly things that are the objects
of the higher philosophy. Having already treated of the
celestial world, as far as our conjectures could reach, we
proceed to treat of animals, without omitting, to the best
of our ability, any member of the kingdom, however
ignoble. For if some have no graces to charm the sense,
yet even these, by disclosing to intellectual perception the
artistic spirit that designed them, give immense pleasure
to all who can trace links of causation and are in-
clined to philosophy." ^

^ Aristotle, 0)i the Parts of Animals, translated by Ogle, London, 1882,
p. 16.

b

0

0

^n

xvili INTRODUCTION

Aristotle regards the physical world as divided into two
realms (the later and now obsolete division into three
kingdoms : animal, vegetable, and mineral, is due to the
alchemists): (1) the organic world (ra e/x^/^fxa) ; and (2)
the inorganic world {tu a\[rvxa)- The characteristic mark
of the organic world is the possession of soul {yfrvxri), by
virtue of which it is endowed with the power of self -move-
ment. Its development and transformations are due to this
native soul-force or life. Life is the universal form of
organic activity ; sensation and the various elements of
consciousness are specific forms. Nutritive life and mental
life are different manifestations of a single psychical power,
the latter representing a higher stage in the evolution of
yf/^vxri- ' Life,' or the inherent capacity of a thing to effect
changes in itself, has several meanings. Whatever
possesses any of the following capacities is said to *live',
(1) reason; (2) sensation; (3) local movement; (4) in-
ternal movement or transformation, viz. nutrition, growth,
and decay. The last power is common to all living things,
and is the basis for the further development of the higher
powers. These various forms of self-movement are
identical with the different types of life. The lowest and
least complex of all the forms is the threptic or vegetal
life manifested in the functions of nutrition, growth, and
decay.

Aristotle conceived of Nature's processes as moving

without a break in an ascending scale from the inanimate

world to the most complex forms of animate existence.^

Natxira nihil facit per saltum. There is an unbroken

* Cf. Hist. anim. 58864; Depart, anim. 681ol2.

THK SOUL AND hlVK XIX

coiitiiiiiily ill torrt\strial liiV^ 'J'ho initial i'orin of this iH
found in plant-lifo. TLo plant-organism is siniplor than
any otlior, its functions are confined to nutrition and
reproduction. I'lie function of growth or vegetation in
plants is analogous to the nutritive functions in higher
organisms. A process of conversion and assimilation is
carried on in both cases and by analogous organs. Roots
are analogous to the moutlis of animals,^ or, as Aristotle
elsewhere employs another analogy, they are like umbilical
veins that take in nourishment from the earth as the
embryo is maintained by its attachment to the uterus.*^
Plants, furthermore, as Aristotle observed, exhibit the
morphological tendency to develop their organs at the
extremities, while animals tend to develop theirs at the
centre.^

The transitional form of life in proceeding from plants
to animals, or from phenomena of growth to phenomena of
sensation, is found in the Zoophytes. There are some
marine animals, Aristotle says,* concerning which it is
difficult to say whether they are plants or animals, for
many of them grow on rocks and die if detached. To
these transitional forms belong the sponges, holothurians,
star-fishes, acalephae (sea-anemones), and sea-lungs.^ All
of these possess a low degree of sensation, and some of
them are incapable of movement. Aristotle's reason for
classifying sponges amongst animals seems to have been

1 Be an. 4126 3.

2Cf. Depart, anim. 650a 20, 686&35; Degener. anim. 745623.

3 Cf. G. H. Lewes, Aristotle, pp. 187, 192. •* Hist. anim. 5886 12.

^ Cf. Ogle, Aristotle on the Parts of Animals, p. 225.

7

XX INTRODUCTION

that they possess rudimentary sensation,^ although they
are incapable of locomotion, and can be regarded only
as belonging to the initial stage of animal development.
Nature completes the transition from plant organisms to
animals proper by an increased or added activity of the
soul, in which are manifested ithe further phenomena of
sensibility, with which desire is associated, and desire
demands locomotion. An animal soul is a more complex
and more highly developed form of the original life-
principle.

While we in modern times, in popular language at least,
differentiate the life found in the plant-world from that
which is found in the animal-world (though the boundary
between these two is not exactly defined) by the obvious
distinctions of ' vegetable ' and ' animal ' life, Aristotle
regards them as fundamentally the same. He looks upon
the functions of sensation, locomotion, and conceptual
thought as a higher development of the vital principle
found in plants. We distinguish between sensation and
conceptual thought without ascribing them to a different
mind, as Plato did ; but Aristotle goes further and maintains
that not only these, but also the function of nutrition, are
due to the same unitary vital force. It is, however, a
distinctly marked stage that nature makes in the develop-
ment of the vital principle when sensation is exceeded and
rational thought is reached. This new phenomenon is
confined to man, and is the last stage in the evolution of
yfruxri- Soul is, therefore, in the opinion of Aristotle, the
unity in which the principles of life, sense-perception, and

1 But. anim. 4876 9.

THE SOU I. AND UKK XXI

thon«^ht an^ otnhraccil. The.so taken lo^ctlKrr form an
aHCondin<^ Hories in wliicli the lii^^licr form always irjcludcH
and piwsnppoHos the i'ornis below it.^

The function of nutrition furnishes tlie hasiw of
sensation ; sensation furnislies the basis of conceptual
thouoflit. The lower functions exist teleolot/ically for the
hi<j;her. Man, consequently, is the apex of creation,
because all forms of life terminate in him as the complete
development of what is contained implicitly and im-
perfectly in the lower organisms. These forms of life or
soul, as we have enumerated them, are the following :

1. The nutritive or vegetal life.

2. Perceptive power or the life of sensation.

3. Creative power or desire attended by the capacity

of local movement, sometimes called by Aristotle
the kinetic soul.^

4. The life of intellect or reason, called the logistic or

dianoetic soul.

These, as I have pointed out, are various manifestations
of a unitary life. The soul is not divided into separate
faculties or parts. In every organism it is a unit. In this
respect Aristotle differs widely from Plato. The division
of the soul into kinds is only a convenient abstraction.
The soul's powers are not topographically separable as
in the Platonic psychology. The difference in kind is
merely a difference in mode of operation and expression,
determined by the nature of the materials with which the

1 De an. 434ci 23 ff. ^De an. 413a 23, 4136 12—31.

3 De an. 4136 27.

XXll INTRODUCTION

soul is concerned. Thought, growth, and decay are modes
of the single life of the organism. Aristotle, therefore,
conceived his entire psychology under a biological form.

Everything that moves itself contains a duality of
moving principle and thing moved, i.e. a duality of ' form '
and ' matter,' to use Aristotle's metaphysical terminology.
Every living thing, a plant no less than a man, is a
composite being (crupoXoi^), viz. a composite of soul and
body. The soul is the cause of motion and change, and
is therefore the ' efficient cause ' ; it is further that which
determines the form or individuality of the organism, and is
therefore the ' formal cause ' ; it is also the end for which
the bod}^ exists, and is, for this reason, the 'final cause.'
The body is the ' material cause ' or condition of the
composite, while the soul represents all of the principles of
activity in the organism. Soul is defined by Aristotle as
the " entelechy or complete realization of a natural body
endowed with the capacity of life." ^ The soul or vital
principle is not itself corporeal, although it is inseparable
from the body, as form is inseparable from matter.^ Soul
and body are not distinct things that do or can exist apart.
Their separation is only notional. They no more exist
apart than do concave and convex.

Soul is to be found in every part of the body. This is
observable in the case of graftings, where the entire parent
form can be reproduced from a section. Insects live for
some time after bisection, but they do not continue to live

^ Dean. 412a 20, 412&5.

2 This does not apply to the Prime Mover as pure 'form.' The relation
of the active reason to the body is discussed below in the chapter on
Reason (chap. viii.).

TIIK SOUL AND LIFK XXIli

on indelinitoly, because they hick orgaiiH lor inainluinin^
life. As wo go up the scale of living forms, this difiusion
of soul tiiroughout the body becomes less and less marked ;
the higher tlu^ ()rd(M* of life the greater the centralization.
In the case of animals, the body consists generally of three
main divisions : the head, thorax, and abdomen. Aristotle
points out^ that if a wasp's head is cut off, the thorax and
abdomen continue to live for a time ; if the abdomen is cut
off, the head and thorax continue to live. In other words,
the part which is conjoined with the thorax exhibits this
continuance of vitality. For this reason it would appear
that the anatomical centre is also the life-centre. This
is, furthermore, on a priori grounds the best and
most advantageous position. It is reasonable to suppose,
therefore, that nature in her wise economy ^ has employed
this central section as the vital centre.

This view, however, is not merely derivable from rational
considerations, but is also supported by grounds of obser-
vation. The life-centre may be localised not only in the
thoracic region, but specifically in the heart. For this
statement Aristotle adduces the following arguments :
(1) disease of the heart is the most rapidly and certainly
fatal ; (2) psychical affections, such as fear, sorrow, and joy
cause an immediate disturbance of the heart ; (3) the heart is
the part which is first formed in the embryo, and, as he
says in the History of Animals,^ it appears in the egg of the
chicken on the third day of incubation as a red spot (the

'^ Dejuvent. 468a 21 ; Depart, anim. 667^22; De respir. 479a 5.
^Cf. Leibniz's "choix de la Sagesse," PW?ic. 11; also Nouv. Ess. II.,
ch. xxi, 13, Langley's translation, p. 183.
^ Hist. anim. 561a 6-12.

XXIV INTRODUCTION

punctum saliens of later writers) which palpitates and
whose movements are those of an organism endowed with
life.

The heart is at once the physiological and psychical
centre of man. In as much as Aristotle identifies life
with soul, it is a matter of consistency for him to place
the seat of the soul in the vital centre. He rejects the
doctrine of Plato and Diogenes of Apollonia, who re-
garded the brain as the organ of mind. To Aristotle the
brain is merely a regulator for the temperature of the
heart; the brain is bloodless and cool, and the blood
and warm vapours from the heart rising to this are
lowered in temperature. By this physiological device,
conjoined with the service of respiration, Aristotle sup-
poses that the system is maintained in a heat-equilibrium.

The material element in which the soul is immediately
incorporated is heat or fire, but the soul is not identical
with this, as Democritus thought. Nor is the vital heat
ordinary fire, but some subtle principle analogous perhaps,
as Ogle says,^ to that imponderable and hypothetical
matter of the physicists known as Ether. In accordance
with his theory, Aristotle was naturally forced to attribute
vital heat to plants and the cold-blooded animals, but his
grounds for this position are not to be found in any of
the extant works. He had, of course, no knowledge of
the chemical elements of oxygen and carbon. The vital
caloric of the body is kept up by food which serves as
fuel. This heat which, according to Descartes, is produced
by fermentation or, according to Haller, by friction between

^ Aristotle, On Youth and Old Age, trans, by Ogle, Introd. p. 9.

THK SOUL AND LIFK XXV

the blood particles, is bcin^ coiiHtaiitly ^enerat(.'(l and
constantly ^ivon otf. To prevent an excessive production
of animal heat, the respiration of tlii^ lun<^s, alon^ with
the coolin<^ function of the brain above referred to, is the
most important means. In the case of fishes the same
tiling is accomplished by bathing their gills in a medium
of lower temperature tlian their bodies.

As to the cause of the natural and normal extinction
of life, Aristotle says it is due to loss of balance in
the production and consumption of heat. The heat is
gradually extinguished when the generation of heat, as
in old age, is not adequate to the demand of consumption.
The length of life in any animal varies according to its
material constitution and the suitability of its physical
surroundings. As a general rule, animals or plants of
great bulk ^ are long lived ; small ones are short lived ;
sanguineous animals live longer than those that have no
blood ; and a long period of gestation is usually correlated
with long life. The purpose of the threptic soul is nutri-
tion and reproduction. The food which is taken up into the
vegetable or animal organism and nourishes it, has its
end not merely in the continuance of the individual's life,
but has a higher end in the formation of another life of
like kind by reproduction. The function of the individual
is not merely to live, but to reproduce and so to maintain
life's continuity.

^ On the longeyity of animals, see translation, pp. 256-265.

XXVI INTRODUCTION

II.

The Faculties of the Soul.

Plato conceived three psychological elements — which cor-
respond roughly to cognition (i/o>;Tf/coV), feeling (eTriOviuLrjTiKov),
and conation (Ou/uLoeiSeg) — in terms of ethical value. Cogni-
tion has the highest worth, and conation stands next in
rank. Feeling has the lowest moral value. These are
not faculties or SvvaiJ.ei<s of the soul, but ' parts ' (imcpt]). They
consitute real entities in the psychophysical whole, just
as the three divisions of government in the state have
separate and real existence. The two lower parts, how-
ever, have no share in pre-existence or immortality.^ These
are never referred to as powers or faculties (Suvanxei^).

The term ' faculty ' is applied by Plato to certain pro-
cesses of the soul which are determined by the object to
which they are directed or the results they accomplish.
Sense-perception {aicrOtjarig), opinion (So^a), and conceptual
knowledge (cTr la-rriiuLr]) are described by Plato as ' faculties.' '^
The faculties depend upon the reciprocal relation between
subject and object. The ' parts ' of the soul (the Platonic
' parts ' are the historical predecessors of the post- Platonic
'faculties'), on the other hand, are entities, situated in
various regions of the body, and denote certain qualitatively
distinct types of psychical life, arranged on a scale of
ethical value. The seat of reason is in the brain, the
topographically higher region being correlated with the
reason's higher worth ; the conative part is situated in the

*Cf. Siebeck, Geschichte der Psychologie, Th. L, Abth. i., p. 203.
'^Protagoras, 330A.

IllK FACULTIES OK THK SOUL XXVll

thorax, more particularly tho heart, so aH to he the con-
venient ally of the reason in the ethical re<^ulation of the
individual'H life;^ the feelin^^s and appetites are situated
in the abdominal cavity, their ui)[)er boundary bein<^ th(j
diaphrat^m and their chief organ the liver.

Plato's entire psychology, in which the soul's parts
are separated into existentially distinct units with distinct
anatomical organs, is ethico-teleologically determined.
Aristotle's psychology, on the contrary, is biologically
determined ; the soul is a unitary life functioning in
distinct modes or faculties.^ It is a single indivisible mind
expressing itself in nutrition, sense-perception, imagination,
memory, reasoning.^ To Aristotle there is a thinking
substance, a 'soul,' which possesses certain distinct capa-
cities. In the term ' faculty ' or ' potentiality ' there is
implicit the idea of latent or possible activity. Further,
Suva/uLig conveys the notion of being native and not acquired

In their action, manifestation, or processes, the faculties
of Aristotle are merely a convenient classification of
psychical phenomena into groups.* They correspond to
the fundamental divisions in organic life — plant, brute,
man. The psychological faculties or functions, therefore,
represent the several stages in the development of the
forms of organic life. The soul operates in every particular
organism under one or other of these forms, viz. it effects

1 Timaeus, 70A ff.
"^Dejuvent. 4676 25.

^See the chapter on the Creative Reason, chap. viii.

^Cf. Wundt's Grundzilge der physiologischen Psychologic, 4te Aufl. VoL
i. , pp. 10 ff.

xxviii INTRODUCTION

nutrition, or it experiences sensation, or it causes loco-
motion, or it thinks, or in the highest organism it acts
under all four forms. Sometimes Aristotle speaks even of
five faculties, viz. the nutritive, sensitive, conative, loco-
motive, and rational ; ^ again he speaks of four ,2 and at
other times of only three, owing to the identification of the
orectic and sensitive powers.'^

It is evident from this that Aristotle laid no great weight
on any fixed enumeration of the faculties, and he expressly
says that from one point of view these ' parts of the soul '
appear to be indefinitely large in number.* If we regard the
fundamental aspects, therefore, under which the soul mani-
fests itself, Aristotle defines it as that principle by which
we live, have sensation, and think.^ The vegetative or
threptic life is confined to the phenomena of nutrition
and reproduction^ ; sensitive life is confined to the pheno-
mena of cognition when the object is spatially and
temporally determinate, i.e. an individual thing; rational
life is concerned with phenomena of cognition when the
object is an universal or an abstraction.'^ The stages in the
development of organic life are differentiated from one
another in terms of psychical activity ; plants live and
reproduce ; the lower animals live, reproduce, and have
sensation ; man lives, reproduces, has sensation, and reasons.
Each higher stage includes within itself the fundamental
functions of the lower stages. Aristotle's view of

^De an. 414a 31. ^ De an. 41.36 12. ^ De an. 431a 14.
■» De an. 432a 24. ^ De an. 41 4a 12.
^ De an. 413a 22 ff., 41 5a 25; De gener. anim. 740630.
'De an. 4176 22; Anal. post. 87637; De insom. 4586 1 flf. ; Metaph.
9996 27 ff.

NUTKITION AND KIOrRODUCTION

XXIX

ilio physical woild may hr pnjseiited .schematically a.s
followH :

Organic world

(to. tVi^i'xa)

Inorganic world

(rd tli/'uxa)

Vogctablo life

(Nutritii)n

aud roproductlou).

I
Aiiiinal life

Lower animals

(Nutrition, rojiroductiou,

and .sensation).

Man

(Nutrition, roprodnctiou,
sensation, uotftic life).

III.

Nutrition and Reproduction.

Nutrition is the simplest form of organic movement.
Every living thing must have the power of nutrition, for
organic development is not possible without food. All
sensation and noetic activity presuppose this nutritive
faculty as their basis. To use Aristotle's phraseology, those
organisms which assimilate form and matter at once and
are incapable of assimilating form without matter, live
exclusively a vegetative life. In other words, the process
of vegetal growth is a physical process, i.e. the organism
takes up certain corporeal substances into its physical
structure, and it does so through the agency of an inherent
psychical or vital principle.^

In sensation, on the other hand, the form of the object
(without its matter) is taken up by the agent. The signifi-
cance or form of the object is assimilated by sensation ;
the matter of the object is assimilated when the nutritive

1 De an. 4246 1.

XXX INTRODUCTION

power appropriates it. Indeed, the whole of the psychical
life is carried on by means of assimilation. The threptic
power by the instrument of heat converts foreign substances
into forms similar to organic structures, and into these
structures the substances are then absorbed. Analogically
the data of sensation and experience are assimilated into
the concept, and the qualities of things are assimilated into
the forms of sense-perception. The entire process of
psychical life is a process of conversion, in which objects
are reduced to terms of likeness with the subject or
agent.

There was a pre-Aristotelian controversy as to whether
nutrition is effected by the like or the opposite.^ Aristotle
says that assimilation implies indeed original opposition,
but the unlike undergoes in digestion a process whereby it
is rendered like, and as such is taken up by the organism
as part of its physical structure. In their ultimate phases,
therefore, the like is nourished by like. Such is Aristotle's
conclusion on this academic question of the Early Greek
schools, a discussion which had concerned itself mainly
with Epistemology, i.e. with the question whether the per-
ception of a quality is due to the possession of a like or an
opposite quality in the agent.

Food after it has been concocted and assimilated becomes
the means (1) of nourishment, (2) of growth, (3) of
reproduction. It nourishes in so far as it sustains the life
of an individual and enables it to persist ; it causes growth
in so far as it acts quantitatively and enables the

^ De an. 416a25 ; cf. also on the Empedoclean and Anaxagorean theories
of sensation, translation, pp. 35, 150, 166.

NUTRITION AND lUCl'RODUCTION XXXl

individual to attain its noi inal inaHH in devulopmcnt ; ^ it
makes reproduction possiblii by conversion of a part of
the food into sennnal matter.^ One; irmst observe three
main facts in nutrition, viz. the cause, the object, and the
means. The cause is tlie elemental soul or threptic ener^^y ;
the object is the body animated by the soul ; the means is
the food. Food, however, can maintain the life of an
individual only for a limited time. The continuity of
life is accordingly provided for by the deposit of semen,
which contains potentially all the elements of the organism ;
thereby the propagation of a life similar to that of the
parent is secured.^ This is the highest and most important
service of the threptic power, because it gives to perishable
creatures an approximate immortality by perpetuating the
species, and this is what every creature instinctively aims
at. It is the final cause of every creature's natural life.*
All of nature's activity is purposive. Food is utilized for
specific ends and in specific ways. No single substance is
adequate for the nourishment of a physically complex body,
and every organic body is complex. Even the lowest
organisms, plants, employ various substances for their
nutrition. Food, in as much as it is the material for the
formation of body, must contain all the body's substances.
Food, must consequently, be multiform. There is, however,
one element in food which is more nutritive than any other,
viz. the sweet. It is this element in edible things that is
mainly causative of growth, and Aristotle makes a curious

1 De an. 4166 10 ff. 2 j)q g^^er. anim. 725 a 15 ff.

^Cf. Aristotle, On the Parts of Animals, tr. by Ogle, pp. 239, 240.
^Dean. 415 a 29.

xxxil INTRODUCTION

use of this element to explain the relative longevity of
bees.^ Fat is to be classified amongst sweet substances.

Food undergoes no process in the mouth beyond that
of mastication.2 Aristotle knew nothing of salivary glands,
yet mastication, though not itself a digestive process, is a
necessary preliminary to digestion. From the organ of
seizure and mastication the food passes to the stomach,
where it undergoes what Aristotle calls concoction. This
is accomplished by animal or psychical heat, a form of heat
which in its vivifying power differs from ordinary heat
and is supplied mainly from the spleen and liver. The
solid and indigestible portions pass off by the lower bowel,
while the fluid portion,^ which alone is employed in
nutrition, is absorbed by the blood-vessels and intestines.
The stomach and intestines are to animal organisms what
the ground is to plants ; ^ the roots as channels of nourish-
ment for the plant correspond to the blood-vessels in the
animal. The veins have exceedingly fine invisible open-
ings such as the pores in unglazed pottery, and these
minute openings permit the nutritive fluid to ooze through
into them, and by them it is carried from the mesentery to
the heart. Their content is not yet blood, it is an in-
completely prepared serum ('ix^p)-^ ^^ ^^^ heart, the
warmest organ of the body, to which this serum is now
immediately carried from the mesentery by the veins, it is
re-concocted and converted into blood. It is then ready for

^ De long, et brev. vit. 467a 4.

* De part. anim. 650a 10 ff.

' De somno, 456a 30 ff.; Depart, anim. 6516 5 ff.; De gener. anim. 72662.

* De part. anim. 678a 7 ff.

* Hist. anim. 521a 12 ff., 5216 2 ; De part. anim. 651a 18.

NIJTKITION AND lUOlMtODUCTION XXXlll

assimilation into tho orf^ans, for ])iiil(lin«^ up tluMr wjiste,
and lor a(l(lin<r to their irrowth. Tho amount of blood
thus tr(inorat(^d is very small in ])ro{)ortion to the matcrialw
consinncd, otherwise thc^ body would t^row to enormous
bulk. The blood in its iinal state of concoction is carried
by the arteries and veins from the heart to all parts of the
body. Each or<ijan assimilates such elements as are
adapted to its growth. The process of nutrition goes on
most actively during sleep.^ Such parts of the blood as
cannot be utilized in organic anabolism are excreted in the
form of sweat, bile, and nature's various means of relief
through waste, while surplus nutritious matter takes the
form of excess fat, seminal deposit, nails, hair,^ and other
masses whose quantitative permanence is unnecessary for
the maintenance of life.

The two fundamental concepts with which Aristotle's
entire philosophy operates, viz. form and matter, or
actuality and potentiality, are derived from his observation
of organic life. Potential matter in the organic world is
being constantly transformed by an inherent life-movement
into significant structures, and a formative or psychical
principle is constantly active in converting passive matter
to definite ends. Without the soul the body is motionless, ^
and the organs of the body are organs only homonymously*
— a dead hand is only the homonym of a hand, it has the
name of a hand without its significance or function. All
life (not only what is modernly understood by vital

^ De somno, 455a 1.

^ Cf. Aristotle, On the Parts of Animals, tr. by Ogle, p. 202.
De gener. anim. 735a 8 ; De an. 4126 14, 21.

C

xxxiv INTRODUCTION

phenomena, but all rational life) is a form of motion, of
which there are several varieties : yeVeo-f?, au^rjcri?, aXXoiWi?,
^opd. The most elementary form of organic movement is,
as has been said, growth (au^rja-ig)} The soul is in e very-
part of the body, and, although not itself corporal, it is
inseparable from the body. This diffusion of soul is more
apparent the lower we go in the scale of animate exist-
ence.^ Organic centralization increases in direct ratio with
the complexity of the organism, but even in the lowest
forms of animal life there is a certain degree of centraliza-
tion, lowest of all in the plants. The only form of life
which is separable from the body is that of the active
reason, and even this, so far as its real content is concerned,
is an ' entelechy of the body.'

Heat is the soul's material substrate, in which the soul is
immediately incarnate. The soul is not itself heat. " Birth
is the original suffusion of the nutritive soul with heat,
and life is the maintenance of this heat." ^ The manner in
which this heat is maintained by the fuel of food through
concoction has been already described. Not only must the
body have this heat in order to live, but the heat must be
regulated and kept within normal limits. There must be some
physiological provision for the reduction of temperature ;
otherwise the fuel in the stomach would constantly generate
heat to excess, especially during the process of digestion.
Mechanism for reducing temperature in the pulmonate

1 Phys. 260a 25 ff.

^Dean. 4116 20, 4136 20.

^ De respir. 479a 29. Birth or genesis means for Aristotle not the
separation of the young from the mother's body, but the process of
fecundation.

SENSATION XXXV

animals is iurnislicd by the liiii<^s ^ and ])rain, in acjiiatic
animals by the t^ilLs. Deatli comes to all or<^anisnis when
th(3 supply of vital heat fails; the ort^ans of nutrition and
respiration become thr()U<^h lapse of time incapable of
supply intij and re^ulatint^ this heat, it being lx)th inade-
quately <^eneratcd and inadecjuately controlled, and so
" the fire of life is snuffed out." ^ When the basal psychical
function ceases, the hi^ijhcr life of mind is no longer possible,
for the soul is not divided into parts, but is an unit.

IV.

Sensation.

The immediate instruments for the apprehension and in-
terpretation of the external world are the peripheral sense-
organs. Sensation, w^iich marks the boundary between the
animal and plant worlds, is explained by Aristotle as a
form of motion, viz. a qualitative change ^ (aWolwa-i^) in a
sense-organ. The sense-process and the sense-object are
one in the actual sensation. Sound and hearing, for
example, although notionally distinct, are identical in the
act of sensation.'^ The sense-organ is potentially what the

^The organs known to us as 'lungs' were regarded by Aristotle as the
right and left halves of an azygous organ. Consequently he always speaks
of ' lung ' in the singular. He found the organ to be actually single in
certain snakes {Hist. anim. 508a 28 ff.), and when it is double the two
divisions have a common outlet in the trachea. I have, however, in con-
formity with the demands of English speech, translated his singular by a
plural. See the translation, pp. 286 ff.

"^ De respir, 479a 18.

^De somno, 4596 4 ; Fhys. 247a 7 ; De an. 415624.

* De an. 424a 25 4256 26, 418a 1.

xxxvi INTRODUCTION

sense-object is actually. To make a further use of Aristotle's
terminology, the organ assimilates the significance or form
of a thing without its matter.^ Life rises above the uncon-
scious process of nutrition, when in sensation the external
world is transformed into a conscious world, a world of
meaning. The sense receives an impression or picture of an
object, as wax receives an impression of a seal-ring without
the bronze or gold of the ring.^ The sense is thus, in a way,
identical with the object ; it differs from the object, how-
ever, in its mode of being. The sense apprehends a quali-
tative element belonging to an individual,^ but not the
individual as such.

Sensation is a process that belongs to both soul and
body.* The sensation itself is psychical, but its instrument
is physical. The eye and vision are related to each other
as matter and form.^ Vision consists in a certain relation-
ship or condition of harmony. Excessive stimuli destroy
this harmony, just as the harmony of strings is destroyed
by striking them violently.^

Without contact there can be no action of one thing
upon another. This law, which applies to the whole of
nature, necessitates the assumption of a continuous medium
from object to subject, for there must be some sort of
contact if the object of sense is to aflfect a sense-organ. A
medium is further necessary because no sensation results

^Dean. 424a 27, 426'x26, 431&26.

^De an. 424a 19 ff. ; De mem, 450a 30.

^Anal. post. 876 28, 100a 16 ff. ; De an. 424a 21 ff.

* De somno, 457a 7 ; De sensu, 436a 6 ; De an. 402a 4 ff.

^ Dean. 412& 18 ff.

6 De an. 424 a 32.

SENSATION XXX Vll

whon or(]jan and object arii in imTn(3diate contact.^ Tho
intervening niedium, li()wev(;r, is in contact with Injth
or<^an and object and transmits a stinmlus from the latter
to the former, without which no sensation would result.
The niedium is different in different senses.

In considerinor the subject of sensation it is necessary to
observe, in addition to the faculty itself, three conditioning
factors : (1) the organ, (2) the object, (3) the medium.
There are five senses, and at the beginning of the third
book of the De anima ^ Aristotle attempts to prove that
this enumeration is exhaustive.

1. Sight.

The sense of sight is the most important for life,^
although hearing has a higher significance for purely
intellectual life, because of the meaning conveyed by the
spoken word.

a. The Organ of Sight — The psychologists preceding
Aristotle and contemporary with him regarded the sense-
organs as composed severally of the elements, but as there
were for the pre-Socratics only four elements (fire, earth,
air, and water), whereas there were five senses, they were
in straits about a fifth element with which to pair a fifth
sense.* Further, they differed in the elements assigned to
the several sense-organs. Plato, e.g., coupled vision with
fire, whereas Democritus coupled it with water. Aristotle,

1 De an. 421& 17, 423&20; De gener. et corr. 322622; Phys. 245a 4.

2 De an. 4246 22 ff. ; cf . also Hist. anim. 5326 29.

3 Metaph. 980a 21 ; De sensu, 437a 5 ff.

4 De sensu, 437a 19 ff.

xxxviil INTRODUCTION

likewise, regards the sense-organs as composed of the

elements, and as to the constitution of the eye he agrees

with Democritus. The eye's power of vision is due to the

element of water in it, the organ being in constitution

analogous to the medium through which its stimulus is

transmitted, i.e. a translucent medium.^ Hearing is due to

the air immured in the inner ear. Smell is correlated with

one or both of the foregoing elements (air and water), and

touch and taste are correlated, perhaps, in some special

manner with earth. The sense-organs are thus coupled

with their media and not with their objects.^ The real

organ of vision is the pupil (Koprj),^ which is within the eye

and is composed of the element of water, and the best eye

is the one whose proportion of water is best adjusted.* In

order that light may penetrate to the interior, it is

necessary that the eye be translucent, and water, because

it is more easily fixed and kept in place, is better adapted

to this purpose than air would be.^ The water of which

the pupil is composed is derived from the brain.^ Aristotle

1 De an. 4246 28 ff. ; De sensu, 4H86 3 ff. ; De part. anim. 647a 2 fiF.

2 The account of the sense-organs given in the Parva Naturalia (De
sensu, 438&3ff.) dififers somewhat from this [e.g. smell is correlated with
fire). The discrepancy is to be explained (cf. translation, pp. 96, 150) by
the fact that in the Parva Naturalia Aristotle is reporting current opinions
(evidently so in his description of smell as a smoke-like exhalation), or it
may be accounted for by the theory (held by Torstrik, but impossible to
establish) that the De sensu is an earlier treatise than the De anima.

^Depart, anim. 653625; Hist. anim. 491621; De sensu, 438a 16 ; De
an. 425a 4.

^ De gener. anim. 780a 22 ; De sensu, 4.386 5 ff.

'^ De sensu, 438a 1 Off. Cf. Theophrastus, De sensu, 39. Diogenes of
Apollonia believed air to be the essential element in the composition of all
the senses.

6 Hist. anim. 492a 21, 495a 11 ff.

SENSATION XXXIX

speaks of three conduits or Tropoi loadin^^ from the eyo to
the brain, which may refer to the raiiiUH ojjhthaimicuH,
opticuHy and ocuUnnotorius, althoutrli he did not, of ccjurse,
regard these as nerves, of the function of wliich lie liad no
knowledge whatever. The optic nerve he recognized as a
duct, and noted the fact that the eye of the chameleon is
continuous with the brain.^ The term iropoq is, indeed,
used later on to mean nerve.^ The connection, however,
here referred to by Aristotle is not a connection between
peripheral and central organ. The duct between eye and
brain serves only physiological purposes, and the connec-
tion is, strictly speaking, not with the brain at all, but only
with the empty occiput and the vascular membrane
surrounding the brain.^ The brain, as has been pointed
out, is not the central sense-organ. The peripheral organs
of sight and hearing are not only connected with the
vascular membrane of the brain, but they are also con-
nected with the heart,* which is the sensory centre as it is
also the vascular centre. Because the eye is connected
with the brain and derives its water from that source, it is
moist and cold like the brain/'' Its power of vision is due
to the translucence of its composition.^

h. The Object of Sight — The object of vision is the visible^

* Hist. anim. 492a 21, 495a 11 flf.; De gener. anim. 7436 35.

2 Galen, De usu part. in. 12, quoted by Ogle, Aristotle On the Parts of
Animals, p. 176, note 19.

^ De part. anim. 6566 16.

^ Hist. anim. 495a 4, 514a 18 ff.; De sensu, 439a 2, 444a 10 ; Depart,
anim. 6526 16, 6566 24 ; De juvent. 469a 10 fF. ; De gener. anim. 7436 25,
781a 20.

^ De gener. anim. 744a 5 ff. ^ De sensu, 438a 12.

'De a7i. 418a 26, 422a 20, 424a 10.

xi INTRODUCTION

and the invisible, for opposites are subject-matter of the same
faculty of perception and of the same science.^ The visible
includes colour and certain phenomena which Aristotle
calls anonymous, whose characteristic is brightness.^ Colour
is a qualitative accident that has the power of exciting or
moving a diaphanous medium.^ Vision consists neither in
an efflux from the visible nor in an image thrown off by the
visible, as the Atomists and Empedocles* supposed, but in
the excitation of a translucent medium by means of colour
and in a qualitative stimulation of the organ of vision by
means of the medium so affected. The diaphanous medi-
ates colour, and light is that which converts the poten-
tially diaphanous into the actually diaphanous. Colour
sets the actually diaphanous in motion and is mediated in
the form of motion from a remote object to the sense-
organ. The diaphanous is not itself visible, but the colour
with which it is charged is visible. The actuality of the
diaphanous is light.^ The diaphanous as such is colour-
less,^ but has the capacity of being illuminated and charged
with colour. The colour constitutes its light in an acci-
dental sense,'^ i.e. light is no particular colour. Light is
not somatic nor the efflux of any body ; it is not fire,® but
depends on the presence of fire,^ or is a subtle species
of fire. As the diaphanous is actually translucent
only in light, so colour is visible only in light. Fire,
on the other hand, is visible in both darkness and

^Deari. 4Ua3; Top. 10ob5; Metaph. 1061a 18.

^Dean. 4 18a 27.

3 Top. 1036 31 ; Categ. 969 ; Be an. 4186 1, 419a 10.

* De sensu, 438a 2. ^ De an. 4186 9, 419a 11. ^ ^e an. 4186 28.

' De senm, 439a 18. « De an. 4186 14. ^ Top. 1346 28.

SKNSATION xli

lii^lit/ lor it crcatcH for itself a tranHluccnt inodiuin by
difluHint^ lit^ht. Colour, then, is a con(liti(ni l)eloii^in^ to
li^ht, as litrht is a condition attachint^ to the diaphanous.
The diaphanous helont^s to water and air, tlie media of
vision, and to some extent to other bodies,- hut has no
independent existence. It is not a substance. Colour is
further defined by Aristotle as a quality of the superficies
of a body in a diaphanous medium. So the Pythagoreans
called colour a visible superficies. There are seven primary
colours derivable from the basal colours, white and black.-*
They are : white, black, yellow, violet, green, and blue. The
other sort of * visible,' called by Aristotle * anonymous,'
consists in brightness produced by a smooth, polished
surface, such as is found in certain fish-heads, scales,
eyes, and phosphorescent substances.* This is not properly
colour, but a fiery phenomenon which has the power of
diffusing light and creating visibility.

c. The Medium of Sight. — The medium of sight is the
diaphanous, viz. air and water and certain other translucent
bodies.^ They are the media by virtue of their trans-
parency, which belongs to them not as air or water, but
because they possess something in common with the eternal
empyrean.^ The medium itself is neutral and colourless,
being thus adapted to saturation with and transmission of
any colour. Aristotle rejects the emanation theory of
colour, and resolves it into a form of movement of a
medium, approximating herein more closely than his

1 De ail. 4186 2, 419a 23. 2 j)^ ,,^,^5^^ 439^ 20 ff.

■^ Deseiisu, 4396 20flf. , 442a 19 ; cf. also translation, p. 87, note 2.
^ De an. 4l9a Iff.; De sensu, 4376 5. ^ De an. 4186 6.

^Dean. 4186 7 ; De sensu, 438a 12.

xlii INTRODUCTION

predecessors to the modern hypothesis of ether vibrations.
Colour excites the pellucid element, which then transmits
the colour-motion from the object to the sense-organ. This
movement does not, however, consist in an undulatory
process, but in a qualitative change, whose spatial propaga-
tion is not discernible,^ and which appears to be instan-
taneously complete.

2. Hearing.

a. The Organ of Hearing. — As the real organ of vision is
composed of water, similarly the real organ of hearing
consists of air. 2 Air is immured in the inner ear and is
immovable there, i.e. it cannot be dispersed. This fact
enables it to detect all distinctions in communicated
motions. We hear in water, because it cannot penetrate
to the congenital air,^ but we hear through water as through
any other foreign body. Aristotle ascribes hearing to fishes,
but nowhere explains how they hear, although in the
History of Animals he devotes several paragraphs to the
subject of sensation in the lower animals.* The congenital
air has its own internal movements, which account for
certain phenomena of sound, such as the hearing of sound
when there is no external stimulus.^ A duct or channel
leads from the ear to the rear of the brain, the occiput,
which Aristotle supposed to be hollow and filled with air.
This 7ro/309 is perhaps the external and internal meatus, or

1 De sensu, 4466 20 ff., 4386 3 ff.

^Depart, anim. 6566 16 ; De an. 419634, 425a 4.

^De an. 4196 18, 420a \\ ; De gener. anim. 781a 23.

^Hist. anim. 5326 30 ff., 5336 Iff. ^ De an. 420a 17.

SKNSATION xliii

pOHsibly ho coii.sidcrcd tlio coiiiiiiunication to Ije eHta))liHljL'd
by tlic EuHtacliiaii tube, wliich wa.s known to hiin.^

h. The Object of Hearing. — The object of bc^ariii^ in
sound.- Sound is produced by tlie concuasion of two hard,
smooth lx)dies, especially hollow bodies, in a medium.^ Aii-
or water may servo as a resisting body and emit sound,
when either is so quickly and violently struck as to pre-
vent its (air's or water's) gradual and noiseless disper-
sion.** Each of these acts then in the same way as a liard
body, and the adjacent water or air serves as a medium for
the communication of the sound. The qualities of sound
are given in terms of pitch, the extremes of which are high
and low, or acute and grave.^ The high or acute is due to
a swift motion, and the low or grave is due to a slow
motion. Mere sound is noise. Voice is significant sound,
produced by an animal, and accompanied by a mental
image.^

G. The Medinin of Hearing. — The medium of hearing as
of sight is air or water.'^ These two media are in their own
nature both colourless and soundless, but capable of trans-
mitting colour and sound to sense-organs. The spatial
propagation of sound is not instantaneous, but is discernible
in time, as one can learn from the blow of an axe seen in the
distance, the sound of wliich is perceived at an interval later.^
For the transmission of sound the air must form an un-
interrupted continuum from stimulus to organ.^ The

^ Hist. anim. 491a 30, 492a 20; De part. anim. 656a 18 ; De gener. anim.
781a 31. "^De an. 418a 11 ; De insom. 458ft 6.

^De an. 4196 6 ff., 4206 14 ; De sensu, 4466 30 ; De coelo, 291a 1 ff.
* De an. 420a 7. ^ De an. 420a 28. « De an. 4206 25 ff.

" De aji. 4196 18. ^De sensu, 446a 24 ff. ^ De an. 420a 3.

xliv INTRODUCTION

stimulus must not be too slight, otherwise it is not trans-
mitted, nor too excessive, otherwise it disturbs the function
of the organ.^ Sensation demands a kind of proportion
between stimulus and organ, from which there issues a
normal organic process.

3. Smell.

a. The Organ of Smell. — The organ of smell is composed
of air or water,^ of the former in the case of respiring
animals, and of the latter in the case of aquatic animals.
In respiring animals the organ of smell has a covering,
which is lifted in inspiration and is analogous to an eyelid ;
without inspiring, smell is not sensed by them.^ In aquatic
animals this covering is lacking, as the analogous eyelid is
lacking in hard-eyed animals.^ The nostrils, or physiological
organs of smell, are passages for inhalation and exhalation,
and are very mobile ; whereas in the case of the ear, man
has no muscular control of it, as most of the lower
animals have.^

b. The Object of Smell. — The object of smell is the odorous
and its opposite.^ Smell is very poorly developed in man,
being inferior in accuracy to that of many of the lower
animals.*^ It is difficult to determine the essential qualities
of smell, because of this imperfect development in man, and
because smells are confused with the pleasant and un-
pleasant.^ Smell is intimately connected with the sense

1 De an. 420a 24, 421 b 9, 422a 26, 426a 28 ff. 2 jr,^ ^ii. 425a 5.

^ De an. 4216 14, 422a 1 ; De se7mi, 4446 22. ■• De semu, 443a 3.

^Hist. anim. 492a 28, 492615.

« De an. 4216 3 ff. ; De sensu, 4446 20 ff.

^De sensu, 441a 1 ; De an. 421 a 10. ^ De an. 421a 12.

HKNSATION xlv

of iaHto/ and nuiiiy Hriu'll.s art) (IcmcmUhhI in UiriuH oi" aiialo-
^ouH flavoiUH, — e.(j. snu^lls aro called Hwoct, piquant, oily,
hansh, puiio^cnt, terms Miat bcJoni^ propc^rly to tawto. Jt is
not, howevei', to be aHsunied that because a <(iven tiling has
a Hweet flavour it will also have a Hwe(;t Hinell. On the
contrary, sweet-smell in*^ objects often liave an unpN^asant
taste and conversely. 'J'he object of smell is described as a
property of the dry, while flavour is the sapid-moist.^
That the dry property is not a smoke-like exhalation, as
certain pre-Aristotelians held, is proved by the fact that
aquatic animals are endowed with smell, and a smoke-like
exhalation could not be transmitted in water.^ Besides,
this would resolve the odorous into a physical efflux, an
explanation of sensation in general v^hich Aristotle rejects.*
The odorous consists in the saturation of a medium (air or
water) with a sapid dry element.^

Although the sense of smell is poorly developed in man,
he is the only animal that is capable of perceiving smell as
fragrance, i.e. in an aesthetic way.^ The lower animals have
no appreciation of malodour as such.

c. The Mediu7)i of Smell. — The medium of smell is air
or water.'^ Water mediates smell for the aquatic animals.^
Man, however, and all respiring animals whose sense of
smell is dependent on inspiration, cannot smell in water.^
Although the media of smell are the same as the media of

^De sensu, 4406 28, 4436 8 ; De an. 421a 17.

2 De an. 422a 4 ff. ^De sensu, 4386 23, 443a 20 ff.

* De sensu, 4436 2. ^ jDe sensu, 443a 3 fif.

« De sensu, 4436 27 ff. , 445a 1. ' /)e an. 419a 28 ff. , 422a 2.

8 De sensu, 443a 1 ff., 4446 5 ff. ; De an. 419a 35, 4216 10.

» De an. 422a 2 ; De sensu, 4446 10 ff.

xlvi INTRODUCTION

sight, viz. air and water, these are media for sight by
virtue of their translucence, and for smell by virtue of their
capacity to exude dry savour. By the peripatetic Theo-
phrastus they are called transolent (Sioa-juia)}

4. Taste.

a. The Organ of Taste. — Aristotle's view regarding the
organ of taste is difficult to determine. He maintains the
doctrine that all the senses function by means of a medium,
and that sensation does not take place when the sense-
object and sense-organ are in immediate contact.^ In
accordance with this doctrine he says the tongue is not the
organ but the medium of taste, and yet he sometimes
speaks in a popular way of the tongue as the organ of
taste.^ Strictly speaking, the organ of taste is something
more internal.* The organ proper is within the flesh and
is fitted with a conductor to the central organ or sensorium
{i.e. the heart).^ It is even possible that Aristotle regards
the heart as the organ of taste and the tongue as at once
the medium and ancillary organ.^ It would seem, how-
ever, from his general account of the senses that they all
have a medium, and that all of them have conduits from
the peripheral organ to the sensory centre.'^

h. The Object of Taste. — The object of taste is at once

^ Cf. translation, p. 75, note 1. ^ Cf. translation, p. 73, note 2.

=' De part. anim. 647a 19, 6536 23 ff. ; Hist. anim. 533a 26 ; De an.
4Q2b 2 ff.

4 De an. 423a 2 ff. ; De part. anim. 6566 36. ^ De semu, 439a 1.

^ Cf. Biiumker, Des Aristoteles Lehre von den dussem und innem
Siimcsvermogen, p, 55.

' Cf. the notes on duct or -rropoi above, under the organ of sight.

SKNSATION xlvii

^^ustablt' jiiul tan^iliK'. 'PaHttJ '\h tlu^roforo a Hpecial form of
tlu' tactual or luiptic hiuisc. It is not perceived throu<^}i
tlio medium of a forei<(ii ])ody )>ut throu<^li an anatomical
medium, in wliich respect it ditiers Irom the seuHeH of si^lit,
hearin<^, and smell. The latter are marked by actio in
distans, while taste and touch operate by inmiediate
contact. This immediate contact is not tlic direct contact
of the sense-object with the sense-organ, wliicli is found in
no sense, but the direct contact of the sense-object with our
physical organism as a transmitting medium. Touch is
more exquisitely developed in man than in any other
creature, and taste, as a kind of touch, shares in this per-
fection. The gustable or flavour is the sapid-moist.
Gustable juices are developed in water or in a moist
element.

There is a great variety of opinions as to how these
qualities originate in water.^ Water is not to be regarded
as panchymic in the sense of containing originally the
germs of all flavours, as was held by Empedocles, but a«
primarily neutral and only potentially chargeable with
flavour. It may be so charged by the processes of nature
or by artificial means.^ Flavours in the moist are especially
developed under the influence of heat. The primary
elements taken alone are tasteless;^ flavour arises only
in their combinations, and it is only in forms of combina-
tion that the elements are fit for food.* Flavour and
the nutritive are closely connected, sweet being the most

^ De sensu, 441ft Iff. -Be seimi, 4416 12 ff.

=^ Be sens2L, 443(x 8 ff. ; Meteor. 3o8& 18.
* Be se7mi, 4416 24 ff.; Be an. 4346 19 ff.

xlviii INTRODUCTION

important flavour in growth.^ The basal flavours are sweet
and bitter,^ from which are derived the other flavours.
The number of flavours, like the number of colours, is
seven : sweet, bitter, salt, harsh, pungent, astringent, acid.^
c. The Medium of Taste. — As pointed out above, the
medium of taste is not outside the body, yet taste operates
through a medium.* We can, indeed, taste in water, but
water in this case is not the medium ; it is charged with a
gustable substance and so becomes the object, not the
medium, of taste.^ The medium of taste is the tongue.^

5. Touch.
Touch and taste are the most fundamental and therefore
the most universal of the senses, because they are necessary
for the maintenance of animal life. No animal can exist
without touch, and only animals can possess it. As it is
necessary to animal life, any stimulus sufficiently excessive
to destroy it, destroys not only the organ, as in the other
senses, but life itself. The other three senses, especially
sight and hearing, minister to higher well-being and fur-
nish materials for intellectual life. Touch and taste are
of primary importance for the maintenance of physical
well-being.^ Although the sense of sight is the most im-
portant of our senses for higher well-being, because of
the great number and variety of sensations with which
it furnishes us,^ yet that man is the most highly endowed

1 De sen.su, 442 a 2 ff. ^ Be an. 422 /> 11 ; Be sensu, 4426 16fF.

3 Cf. translation, p. 87, note 2. * Be an. 435 a 16, 422ft 9.

B Be an. 422a 12. ^ Be an. 423a 15, 4236 17, 26.

7 Be sensu, 4.366 10 ff. ; Be an. 4146 2 ff.

8 Metaph. 980a 21 ; Be sensu, 437 a 5ff.

SENSATION xlix

crcatun' is shown more \)y his toiicli than \)y his si^ht, in
which hitU'T many oi' tho lower crt^aturcH surpaHH him.
Furtlior, men of finest tactual sensi})ility are tlie best
endowed intellectually.*

a. The Orc/an of Touch. — As in tlie case of taste it is not
made clear what the organ is, so it is not made clear
in the case of touch. "^rho organ is described merely
as something intra-corporeal, i.e. it is not the superficies
of the body. Tliis may refer to the central organ as
some suppose,- or, as I think more probable, to some unde-
fined and unknown peripheral organ within the flesh.^

6. The Object of Touch. — The object of touch is the
tangible (aTrroV).* Aristotle's expression contains the
same tautology. Tactual distinctions are such as charac-
terize the body as body. They include warm and cold, dry
and moist, hard and soft.^ The objects of touch do not fall
under a single category. The objects of sight fall under
the category of colour ; those of hearing under the category
of sound ; but the objects of touch are not reducible to this
unity.^

c. The Medium of Touch.-^As it is the function of touch
to apprehend the qualities of body as body, so it is a cor-
poreal medium that transmits these qualities, viz. the flesh.
This sense gets its name from contact, which is possible
only between bodies. The body in general is the medium
of touch, and the tongue is the medium both of touch,
and taste.

1 De an. 421a 15 fF. ^^f Zeller's Aristotle, Eng. tr., vol. ii., p. 66.

3 De an. 422622. ^Be a7i. 4346 12; De gener. et corrup. 3296 8.

5 De an. 4236 28 ff. « De gener. et con-iip. 330a 25 ; De an. 4226 32,

d

1 INTRODUCTION

From the foregoing it will be seen that Aristotle
hampered as he was by the lack of scientific research in
physiology and physics amongst his contemporaries, struck
boldly out into the terra incognita of psychophysics as a
discoverer. His is not only the first attempt to create a
psychology in any approximately scientific spirit, but it is
the first attempt to formulate a psychology at all.

V.

The Common or Central Sense.

Aristotle's conception of a ' common sense ' (koipov
ala-6r)Tripiou)^ has no logical or historical connection with
the Scottish philosophy of common sense. Sir William
Hamilton, in his elaborate note appended to the works of
Reid),^ gives four meanings in which the term ' common
sense ' has been employed in ancient and modern times :
1. It was employed by Aristotle and the Peripatetics to
signify sense proper, and denoted that faculty by which
the various reports of the individual senses are reduced to
the unity of a common apperception. 2. It has been
applied not to sense proper, but to those cognitions and con-
victions which we are supposed to receive from nature and
which all men possess in common, whereby we test the
truth of knowledge and the morality of acts. This is
the meaning in which it is employed in the Scottish philo-
sophy. McCosh called it the Intuitive Philosophy, i.e. the

^ De an. 425a 14 ff. ; De somno, 455a 21; De long, et brev. vil, 467&28,
469a 12.

"^ Reid's WorkSy edited by Hamilton, vol. ii., pp. 751 flf.

Til 10 COMMON OH (.'KNTKAL SKNSK H

pliiloHopliy whicli rct^ardn the coniinon IiiluiUoiis ol" the
mind an ihu criteria oi' truth.

Dut^ald Stewart objoctod to the term ' common hoiihc; ' on
the ground of its amhij^uity, and preferred to call thewe
common convictions " ihv. fundamental laws of huuiaii
belief." Connnon sense, he asserts, is nearly symjuymous
with mother-wit, and good sense is only a more than
ordinary share of common sense. These primary or intui-
tive truths are what Aristotle calls ultimate principles
(apXOLt), but not principles of common sense. He says in
the Nicomachean Ethics : ^ " What all men believe, that we
affirm to be ; and he who rejects this belief will advance
nothing that is more convincing," which is the equivalent of
the dictum : quod semper, quod ubique, quod ah omnibus.
These universal beliefs, which Aristotle regards as the
fundamental principles of human knowledge, are akin to
the ' fundamental laws ' of Stewart. The doctrine of the
census communis y however, is quite distinct from this.

3. Common sense, when used with an emphasis on the
^jective or substantive, indicates that kind of intelligence,
the lack of which causes one to be accounted mad or foolish.

4. It denotes an acquired perception of the duties and pro-
prieties expected from each member of society ; a sense of
public spirit, a feeling of obligation towards the commonweal.
The last three meanings are all metaphorical, and do not
refer to sense proper, but to certain intuitions which, like
sensation, are characterized by immediacy, origiiiality, and
presumed trustworthiness. Thus we speak metaphorically
of a ' moral sense/ a ' logical sense,' or an ' aesthetic sense.'

^Eth. nic. 1173a 1.

lii INTRODUCTION

Aristotle employs ' common sense ' to signify a specific
aspect in the psychological process of sense-perception.
The act of sense-perception is not completed in the peri-
pheral sense-organs, but only in the central sense.^ There
are, as enumerated in the previous chapter, five peripheral
organs of sense : the eye, ear, tongue and throat, nose, skin
and flesh. These are stimulated by objects in the outside
world, which by contact with the organ work some change
(aXXoLcoG-ig) in it. The contact is effected through a medium
which transmits a stimulus from the sense-object to the
perceiving organ, and the change which the stimulus works
in the peripheral organ is further transmitted by the blood
or sense-duct to the sensorium (central organ). In every
sensation three factors are to be taken into account : (1) the
organ, (2) the object or thing sensed, (3) the medium of
transmission. In the case of vision, as explained in chap.
IV., these factors are the eye, the thing seen, and the
diaphanous or translucent medium, whether the latter be
liquid or atmospheric.

Every sensation presupposes these three elements :
organ, object, and medium. To each of the individual
senses belongs the function of apprehending a particular
quality (ISioi^ ala-QrjTou).'^ In vision, only colour is sensed ;
in hearing, only sound ; in smell, odour ; in taste, flavour
and in touch, the qualities of body as body (hardness, etc.).
These are all sensation-qualities, but they are not percepts.
By means of sight, e.g., we have the sensation of green, but
do not perceive an olive. An olive is a percept ; green is a
sensation. An olive is made up of several ideas, of hard-

1 De an. 4266 10 ff. ; De somno, 455a 10 ff. "^De an. 418a 10 ff.

TUK (X)MMON OR CKNTKAL SKNSK lili

nesH, tasto, colour, form, ina<(nitii(le, etc., and tlicHo are
unified in a particular thin*;, and tlioy constitute it a winf^le
concrete object. The j)('riplHM'al ()r<^anH of toucli, tawtc;, and
sight furni.sli us with several ideas or qualities belontring to
a concrete thin(^ ; but it is only by tlie unifying function
of the central or common sense that these various qualities
are brought toirether for knowledo:e and seen to inhere in
a single object ; in other words, it is only then that a
percept is formed. The function of sensation, therefore,
belongs to the peripheral or external senses in so far as
they mediate the qualities of an object to the sensorium or
common sense. Perception,'^ then, is one of the functions
of the central sense.

Again, it is by means of the central sense that we
recognize particular sensations as belonging to ourselves,
and can hold them up before our minds as something known
to us. We know that we see. In other words, we are
conscious of a sensation. Consciousness,^ then, is a second
function of the common sense. Locke made a distinction
between what he called the external and the internal senses.
The external sense gives us ideas of colour, sound, and other
properties of body. The internal sense gives us ideas of
thought, reasoning, memory, and the other operations of
our own minds, and is another name for consciousness.
This function, so far as it is limited to. the consciousness of
sensations and their meaning for perceptual knowledge, is
ascribed by Aristotle to the common sense.

Again, there are in addition to the particular sense-
qualities (iSia aia-OrjTo.), such as odour, sound, colour, etc.,

^De sensu, 449 a 3fF. ^ De an, 4256 12 ff. ; De seiimi, 455 a 15 ff.

liv INTRODUCTION

certain properties attaching to things which Aristotle calls
' common sensibles ' (koivo. aia-OrjTa)} These are rest, motion,
number, shape, and magnitude. They are called ' common '
because their apprehension does not belong directly to any
particular sense (although they are perceived indirectly by
each), and because they are cognized directly by the common
sense. They differ from primary or simple sensibles in
having no specific sense-organ. This is a third function of
the sensorium commune. Again, the individual senses
furnish us with colour, sound, etc., but it is not their function
to discriminate, e.g., between sweet and white, or to differen-
tiate degrees of bitter. This is a function oi judgment^ and
it is ascribed by Aristotle to the common sense. The dis-
crimination between true and false, between real and
unreal in our perceptions is made not by the peripheral
senses, but by the central sense. The sensation, because it
is only a fact and as a sense-process pronounces no judg-
ment, is always true,^ but when the sensation is predicated
of something and a j udgment is expressed, error is possible.
It is the internal or central sense that performs this office
of judgment in the sphere of perceptual knowledge, and it
is, therefore, to the central sense alone that, strictly speak-
ing, truth and falsehood in this sphere can be ascribed.

Further, sleep,* imagination,^ memory,^ and dreams,^ in
so far as they signify the interruption of consciousness or
the continued life and movement of residual sense-percep-

^ De an. 418a 17, 425a 16; De mem. 450a 10. Cf. translation, p. 96,
note 2.

2 De an. 426 /> 14 ff. ^ De an. 427 & 11, 428 a 12.

^ De somno, 454a 2.3, 456a 1. ^ De imom. 460?> 17.

^ De mem. 451a 17. ' De insom. 458 & 1 ff.

TUK COMMON OR CKNTIIAL SKNSK Iv

tiona, arc luiictions ol" tlie .stMisoiium. In Hunnnary, these
various functions of tho central or common sense are as
follows : 1. The unification of the primary sensibles, or the
complete act of sense-perception ; 2. Consciousness ; 3. The
suspension of consciousness, or sleep ; 4. The cognition of
the ' common sensibles,' magnitude, number, etc. ; 5. Judg-
ment, in so far as judgment applies to the comparison,
contrast, and discrimination of the deliverances of sense ;
6. Imagination, or residual sense-images ; 7. Memory (in-
cluding reminiscence), or the voluntary and involuntary
reproduction of sensations ; while lastly, 8. its content is the
potentiality of reason.

As the peripheral senses have an object, a medium, and
an organ, so also has the central sense. The objects are the
' common sensibles ' and the several particular sensations
which are unified by the central sense into the perception
of a single concrete thing ; the medium is the blood and the
particular sense-organs ; and its own organ is the heart.^

^ De Juvent. 467&28 ff., 469a 11. Aristotle's reasons for rejecting the
brain as the sensory centre may be summarized as follows : 1. The brain
of a living animal appears to be insensible to touch {Hist. anim. 520616).
2. Aristotle was unable to discover any brain in the invertebrates, except-
ing the Cephalopods. The ganglia in other invertebrates, owing to his
lack of instruments, escaped his notice, 3. The peripheral organs (eye, ear,
and nose) are not, strictly speaking, connected with the brain, but only
with the vascular membrane surrounding it. 4. The sense-ducts are con-
nected with the heart, from which radiates the entire vascular system.
5, The heart is the primum vivens, vltimum moriens [De part. anim.
666a 20, 667a 20 fif. ; De juvent. 4686 28) in animal life, and as sensibility
is the most fundamental animal characteristic, so the heart would appear
to be the most fundamental organ of this characteristic. 6. With loss of
blood sensibility is lessened. 7. The heart's action is plainly affected by
pleasure and pain. 8. Its central, acropolis-like position indicates that
nature's economy intended the heart to be the organ of government.

Ivi INTRODUCTION

VI.

Imagination and Memory.^

The process of knowing, according to Aristotle, develops in
three different stages : 1. The primary stage or simplest
form of knowing is sensation (aLcrOrjcrLg) ; 2. The second
stage is imagination ((pavTaa-ia), or the power of using
images of absent objects ; 3. The third stage is rational
thought (vovg). Although imagination differs from sen-
sation and conceptual thought, it is not possible without
sensation ; and thought, in turn, is not possible without
imagination. Imagination is the persistence of a sense-
impression after the removal of the sense-stimulus, described
by Hobbes as "decaying sense," ^ and by Aristotle as a
weaker ^ or less clear sense.

Imagination mediates between sensation and thought.
Sensation furnishes the mind with a body of impressions
and copies of the external world, — the raw material which
imagination and thought employ.^ Imagination is a store-
house, as it were, of copies of sense-objects, which persist
in the mind as images after the seen or heard objects have
been removed. I no longer hear, e.g., the song that once
stirred my sense, yet it sings and repeats itself in the
auditory imagery of my mind. I no longer see the player
distraught with the woes of Oedipus, yet the picture of

^See translation, pp. 110 ff.

^"Imagination therefore is nothing but decaying sense," Hobbes'
Leviathan, Part I., ch. 2, p. 7. Oxford, 1881.

^Bhet. 1370 a 28.

** Aristotle's distinctions between imagination and sensation are more
minutely given in note 1, translation, p. 110.

IMAGINATION AND MKMORY Ivii

his tragic I'aco roinaiihs in my lil'(M)f visuul inia^^iimtion. In
this inoanintij, ima^^iiiatioii in the powiji- to hold the im-
pression of sense al'ter the sense-o})ject has ^one. Sensation
refers to a present impression ; imagination refers to an
impression of somethin*^ tliat is no hm<rvA' Vxjfore us.
Imat^ination is necessary, therefore, to the life of tliought
and memory, for witliont it mind would be only the ever-
.shifting scene of kaleidoscopic sense-impressions which,
once gone, could never be revived. Imagination partakes
of the nature of both thought and sensation ; like thought,
it is a subjective, internal activity ; and like sensation, it is
the passive receiver of images and forms from the external
world.

The word (pavTaa-la is used by Aristotle to mean both
the faculty of imagination and the product of imagination.
For the latter meaning, however, he ordinarily employs
the word phantasm {(pavracT/iMa). There are three more
or less distinct senses in which Aristotle makes use
of the term phantasm : 1. Appearance ; 2. Phantasm or
false appearance ; 3. An internal mental picture of an
absent sense-object. It is in the last meaning that the
term is usually employed in his psychological treatises.
The word (pavTaala is akin to 0ao9 ('light'), and
^avTOL^ea-Qai ('to appear'); and there is in the word an
implied distinction between the phantasm and the real ;
it is appearance versus reality. Yet while the image is not
the real thing but only the real thing's form, it may be
a true copy of the real, and, as such, it is as true as sensa-
tion. The two prominent elements expressed in the word,
looked at etymologically, are form and light, without

Iviii INTRODUCTION

which the sensible world is not revealed to us. As the eye
reveals to us an external world of form and light, so
phantasy reveals to us an inner world of forms, colour,
perspective, and light, — an inner world corresponding in
its imagery to the world of lighted space.

The psychophysical process by which imagination is
produced is conceived by Aristotle as follows : Sensation is
due to a movement set up in the sense-organ by a present
stimulus. This movement has the power to persist after
the stimulus has been removed. Just as one throws a
pebble into the water and sets up a circular movement
therein, and this moving circle creates a second by its
energy, even after the pebble has disappeared, and the
second circle in turn communicates its movement to a third,
growing fainter the while, so a sense-stimulus sets up a
movement in the sense-organ, which in turn communicates
its movement to the blood, and the blood, under favourable
circumstances, conveys it to the heart, which is the organ
of consciousness and of the higher activities of the mind.
By favourable circumstances Aristotle means cases where
the movement is not inhibited or interfered with by
counter-movements of sensation, and where the sensation
is strong enough to persist. In the midst of the cross-
currents of our motley life of sensation, the movements set
up by given stimuli are constantly crossed and impeded by
other movements, and there arises amongst them, as it were,
a struggle for existence, to employ a much used formula of
modem biology.^ Those movements which at the moment
are strongest, reach the heart and become phantasms or

1 De imoni. ACAa \ ft".; De an. 4286 lOflf.

IMAGINATION AND MIOMOHY lix

conscious imap^es. Similarly also to the fainter (expression
of the coiniriiinicated movement in tli*' illustration drawn
from the pel)])le/ the communicated movement in the
phantasm is fainter tlian that in the oritrinal sensation.

In a passage in tlie Rhetoric already referred to,
Aristotle describes a phantasm as a " weak sensation,"
which is very like the view of Hobbes, who says : " All
fancies are motions within us, reliques of those made in
the sense." ^ These movements of the imagination are, as
one might expect, especially characteristic of sleep, during
which the sense-activity is suppressed. Dream-images are
not always copies of the real world, but often merely a mass
of confused, distorted forms having no apparent relation to
actual things. Imagination, therefore, has two forms :
(1) That of revived or residual sense-perceptions, i.e. copies
or images of the real world, in which the imagination is
passive or receptive ; (2) That of reconstructed o^ created
images, in which the imagination is active and productive.
The one form of imagination is called by Aristotle (pavTaala
aiaOrjTiKy, the perceptual or reproductive imagination, and
the other form (f>avTaa-la XoyiarTLKi], the constructive or pro-
ductive imagination.^ The latter belongs only to man, the

^ De insom. 461a 20 ff. and note 1, translation, p. 242.

^ Letnathan, p. 12 (Part I., ch. iii). Cf, Freudenthal, Uehe.r den Begriff
des Wortes (pavraaia hei Anstoteles, p. 24.

^ In modern psychology imagination and thought are less differentiated
than in Aristotle's writings, where imagination is always either the reproduc-
tion of sense-elements or their reconstruction into new images, withovit loss
of their sensuous or picture character. Of constructive imagination Titchener
says : " It is a ' thinking ' or judging not in words but in reproductive ideas.
Psychologically, then, there is no difference between the ' imagination '
of the poet and the 'thought' of the inventor" {Outline of Psychology^
p. 297).

Ix INTRODUCTION

former to the brute creation as well as to man. Further,
the imagery accompanying general notions and concep-
tual thought is a creation of the productive imagination.
The latter form of imagination is due to a free initiative
power in the central organ, which may take the character
of a logical construction of the elements of sense-imagery
into a coherent complex, such as is exhibited in a creation
of literary or plastic art ; or it may take the form of
arbitrary, incoherent, confused image-masses, as exhibited
in sleep, in the delirium of fever, or in the excitement of
vehement desire or violent passion. Such distortions and
malformations, corresponding to no real things, are due
mainly to physiological causes, especially to excessive heat
and disordered movements in the blood. They occur
mostly in sleep, because the activities of thought and
sensation, which act as regulators of imagination by day,
are suppressed in sleep, and, consequently, the activities of
imagery have then complete control of the central organ.
These phantasies, uncontrolled by waking consciousness,
resemble the imagery of clouds, which, as Aristotle says,^
at one moment represent a centaur, at another a man, and
are constantly shifting in their forms. Melancholy has
great influence in the production of pictures of phantasy,
because it generates excessive heat in the central organ ; so
also have such pathological conditions as are found in
ecstasy and madness, observable in the case of sibyls and
religious maniacs, in whose minds the pictures of fancy are
regarded as real objects. In these cases right judgment,

^ De, imom. 460Z> 12, 461?) 20; Metaph. 1024622; Proh, 9953a lOflf.,
9576 10 ff.

IMACUNATION AND MKMOHY Ixi

whii'h normally aH.si.st.s in tlui regulation ol' llici inuige-
makin^ function, is inhibited. Tnia<^ination, tlicii, in for
Aristotlo both an image-receiving and an image-producing
powcr.^ As an image-receiving or image-holding power, it
is the source of memory and recollection. 'JMiis is the
reproductive function of imagination. A memory or
memory-image differs from a phantasm in two particulars :
(1) memory regards the phantasm as a copy of something,
while imagination regards it simply as a picture ; (2)
memory regards the thing, of which the phantasm is a
copy, as having been seen or known by us. It is recog-
nized as part of a past experience.

The deliberate and conscious calling up of this copy
is recollection (avdiuLi'rjcrig). Recollection depends on the
original coherence of the movements or elements in experi-

^ That Aristotle employs imagination in these two senses is, I think,
demonstrable. The terms above cited, (pavracria aladrjri.K'q and ^auraaia
XoyLariKT} {De an. 433629), are thus most consistently explained. Further,
in the aims of art and the ends of conduct Aristotle employs imagination
in the constructive or productive sense {De poet. 145oa22flF. ; Eth. Nic.
11386 20tf. ), and he sharply distinguishes between the sense-imagination of
the lower animals and the rational employment made of it by man {De an.
434ra6, 429a Iff. Cf. Frohschammer, Ueber die Principien der aristotelischen
Philosophie, pp. 52 ff. ; and Teichmiiller, Aristotelische Forschungen,
Vol. II,, pp. 149 ff.). Again, it is possible to call before the mind an
imaginary object, a new and more or less arbitrary construction, which is
not possible in reproductive imagination or in discursive thought controlled
by rigid laws of procedure {De an. 4276 15 ff.). Butcher, although he
denies that Aristotle employed the term in a productive sense, yet in his
account of phantasy implies (correctly, I think) that Aristotle did use the
term in this meaning {Aristotle's Theory of Poetry and Fine Art, pp. 126 ff.
and Preface, p. viii. Cf. also Freudenthal, op. cit., pp. 31, 45). It is not
to be supposed, of course, that Ai'istotle thinks of two imaginations, but
merely of two functions of this psychological power — the one concerned
with the reproduction of sense-elements, and the other with their logistic
or rational reconstruction into new forms.

Ixii INTRODUCTION

ence. By virtue of this original coherence one image is
called up by another formerly connected with it. The laws
of association in memory^ are described by Aristotle as
(1) similarity, (2) contrast, (3) contiguity.^

Productive or active imagination, on the other hand,
creates images that do not correspond with past experiences
or sensations, but which have only an ideal or subjective
existence. These images are the phantasies of dream-life,
of delirium, of art-creation, etc. It is to the imagination
that art appeals. The image-making power is the sub-
jective source of art imitation (jULiinrja-i^). It is the function
of imagination to clothe the idea in a picture or figured
space and thus to mediate between the outward work of
art and the internal idea. Art, in Aristotle's opinion, is
essentially mimetic. Imitation in art is, in the first place,
an imitation of a picture in the phantasy. Measured
alongside the work of art, the mental picture or phantasy
is an abstraction. The work of art is the concrete ideal,
and here phantasy is active and creative. The mental
image itself, however, is either a mimetic picture of the
sensible real or it is a purified picture of the sensible
real. When art is not merely mechanically reproductive
or crudely mimetic, but is the purified or cathartic picture
of the real, then (Aristotle says) poetry is more philoso-
phical and more serious than history.^ History is par-
ticular ; poetry and art are universal, idealistic.

^ Aristotle says that experience, whicli is akin to science and art, is
derived from 'much memory' {Anal. post. 100a 5; Metaph. 9806 29). Cf.
Hobbes' Leviathan (ch. ii., Part I.), p. 7 : "Much memory, or memory of
many things, is called experience."

2 De mem. 4516 10 tf. » j)^ p^g^, 14515 5 g-.

IMA(aNAT]()N AND MKMORY Ixiii

The relation botwuc^n pluiiitasy and ai-tiHtic j^cnius \h
iinl'ortunately Hcara^ly nioi-o than touclujd upon by Aris-
totle. Iniajj^ination i.s tlu^ normative and directing power
in art, because it is iina<^ination that places before the
artist the end he wishes to attain, and this i^nd is given
in the form of a mental picture or image. The art-object
exists in phantasy prior to its existence in reality. The
creations of art are the projections of internal phantasms
into the various forms of art-expi"ession, — into the form
of tixed and arrested matter (sculpture and architecture),^
or into the form of fluent, rhythmic verbal symbols
(poetry), or coloured superficies (painting), or melodious
sequence of sounds (music). In every instance art is
concerned with appearances (^ai^Tacr/xara), and is, there-
fore, always sensuous. It is clothed exclusively in imagery
drawn from the sense-world, even the rhythm of poetry
being an imitation of aesthetic movement in a world
of sensible motion.

The final function of imagination, in Aristotle's account,
is to supply the schematic form in which the higher
activities of conceptual thought are clothed. The reason
needs general images for the schematism of general
notions, and such schemata are supplied to vovg by the
productive imagination. Furthermore, imagination medi-
ates the sense-world to the reason, and thought interprets
the imaged world of sense in the forms of science and
philosophy.

^ Architecture is not included amongst the fine arts by Aristotle, because
it serves practical ends and its primary purpose is not to minister to the
aesthetic emotions, and further because of its non-imitative character. Cf.
Butcher, Aristotle's Theory of Poetry and Fine Art, pp. 146 ff.

Ixiv INTRODUCTION

VII.

Practical Reason and Will.

The practical reason differs in its function from the
theoretic reason. These are not two reasons, but one
reason operative in two distinct fields, viz. in the field of
knowledge and in the field of morality; and as the subject-
matter and results in the two cases difier, so the two
functions have received different names. The function of
the theoretic reason is to discriminate between the true
and the false ; the function of the practical reason is to
discriminate between the good and the bad.^ The former
knows; the latter judges, weighs, evaluates, advises, and
determines. The practical reason is concerned with de-
liberation and conduct, with knowledge as applied to
action ; the theoretic reason is concerned with knowledge as
such. The theoretical reason gives no commands. The
practical reason operates in the form of a practical syl-
logism, whose conclusion is epitactic or imperative.

Aristotle describes this syllogism as follows : All de-
liberate action is resolvable into a major and minor
premiss, from which the given action logically issues.
The major premiss is a general conception or moral
maxim ; the minor premiss is a particular instance ; and
the conclusion is an action involved in subsuming the
particular instance under the general conception or law.
The conclusion is not an abstraction, as in the case of a

iZ)e an. 43l^>10, 433a 14, 434a 16 ; Eth. nic. 1144a 31 flf., 1147a 1 fif. ; De
motu anim. 701a 7 ff.

PRACTICAL HKASON AND WILL Ixv

theoretical Hyllo^i.siu, })ut con.siHtH in an actiioii and is
juHHivo, C.ij}

Major pn^misH : All iihmi should take exerciRe ;

JMinor pi-eniiss : I am a man ;

Conchision : I should take exercise ;

Or,

LiHit meats are wholesome,

This is a light meat,

.'. It is wholesome.
Our En<xHsh phrase 'acting on principle* is, as Grant
pointed out, the e(juivalent of Aristotle's practical syl-
logism.'^ The practical syllogism operates in the sphere
of conduct, of choice and the variable ^ (to. evSexo/^^va aXXaj?
tx^iv), not in the sphere of necessary truth as is the case
with the speculative reason, whose aim is demonstrable
truth, whereas the aim of the practical reason is the good,
the prudent, the desirable. The content of the conclusion
as knowledge is the essential matter for the former ; the
content of the conclusion as motive is the essential matter
for the latter. The main business of the former is with
the understanding, of the latter, with the will ; the prin-
ciple of ' sufficient reason ' is related to the understanding
as the principle of ' final cause ' or motive is related to the
will.* In the practical syllogism obligation is vested in
the conclusion, and the particular or minor premiss is more
cogent than the major, i.e. it is not the general law, but the

1 De motu anim. 701a 27 ; Eth nic. 11416 18 flf.

"^ The Ethics of Aristotle, edited by Sir A. Grant, 3rd ed., London
1874, Vol. L, p. 269.

^Eth. nic. 1140a 32 ff., 1141a 1 ff.

''Of. Grant, op. cit., p. 263. Also De an. 432a 10 ff., translation p. 132.

e

Ixvi INTRODUCTION

application of the general law to a particular person, that
stimulates to action.^

The virtue characteristic of the practical reason is
prudence or practical insight ((ppoptjang). " Prudence is
neither a science nor an art ; it cannot be a science because
the sphere of action is that which is variable; it cannot be
an art,^ for production is generically different from action;"^
and although Aristotle rejects the Socratic doctrine that
virtue is knowledge (the sphere of moral life is pleasure
and pain, rather than knowledge),^ he goes on to say that
the " presence of the single virtue of prudence implies the
presence of all the moral virtues." ^ Prudence, however, is
not itself the whole of moral virtue : " moral virtue makes
us desire the end, while prudence makes us adopt the right
means to the end." ^ Although men act on general principles
and laws, they do not perform general acts ; all acts are
particular; and so Aristotle, in describing the practical
reason and its characteristic moral quality of prudence,
further differentiates it from the theoretic reason by saying
it is concerned immediately with particulars {alo-Orjai^,
€<JX.aTOv, irpaKTOv ayaOov, to KaO' eKacTTOv)^

The jussive character of its conclusion is, indeed, derived

^Dean. 434a 17.

2 Human activities are classified by Aristotle into three main groups : (1)
knowledge, (2) action, (3) production (art). To these three groups of
activities he assigns the following corresponding forms of science : (1)
theoretic, (2) practical, (3) poetic. Cf. Metaph. 10256 20 flf.

^Eth. nic. 114061 ff.

*Eth. nic. 11046 9.

'^Eth. nic. 1145a 1 Peters' translation (4th ed., London, 1891), Bk.
VI., 13, 6.

^Eth. vie. 1145a 5 (Bk. VI., 13, 7).

'/;<//. nic. 1141616, 28, 1142a 22, 1142a 25-30.

PRACTICAL HKASON AND WILL K'vii

from tlic inajoi" [)it'ini,ss, but only \)y applying tlic major
promi.sH to a paiticular iii.staiici^ The cmpiriwil knowledge
of particular facts is more iimiuMliately important. "Prud-
ence ^ does not deal in general propositions only, but implies
knowledge of particular facts also ; for it issues in action,
and the field of action is the field of particulars. This is
why some men who lack scientific knowledge, especially
men of wide experience, are more efficient in practice than
others that have such knowledge. Prudence is concerned
with practice and needs both general truths and particular
facts, but more especially the latter." ^ It is the particular
or minor premiss that is most cogent in stimulating to
action. The minor premiss, however, is immediately per-
ceived and often obvious, and the practical syllogism then
has the form of enthymeme.

The epitactic quality of the practical reason is not think-
able apart from the virtue of the will. It can legislate,
but not execute. Volition is not vested in it, although no
moral volition is possible without it. However, as a
legislative power it guides the will by enlightening it.

^ Walter identifies practical reason and prudence, and regards the
doctrine of a vovs irpaKTiKbs as a late interpretation of Aristotle, due to
an incorrect translation of Albertus Magnus. Walter's distinctions,
although very acute, seem to me not only unprofitable refinements, but
of questionable hermeneutic soundness. The fact that the process here
referred to is described by Aristotle as syllogistic and issuing in conduct
{De an. 433a 1-16), and the frequent reference to practical reason as a
distinct psychological power {wpaKTCKos vovs, De an. 433a 16, JSth. nic.
1142a 25-30; didvoia irpaKTiK-f}, De an. 4336 18, Pol. 13256 18 ; X670S irpaKxiKos,
Pol. 1333a 25), seem to show that Aristotle regarded this not only as different
from the theoretic function or reason, but also as different from <pp6vr)<Ti.s
(prudence) as a moral quality. Cf. Walter, Die Lehre von der praktischen
Vernunjl, Jena, 1894, pp. 15 ff.

'^Ethnic. 11416 15 ff.

Ixviii INTRODUCTION

By will Aristotle understands any effort towards the good.
The lowest form of will is impulse ; its highest form is
rational desire.

Aristotle, like Plato, developed his ethical doctrines in
the closest connection with his psychological theories. His
conception of the moral will and its function is determined
largely by his theory of the practical reason. In his
analysis of the elements of consciousness, he finds only what
we should call ideational and affective elements. There
is no reference to any third conative element. The two
component elements in the ethical will are practical reason
and desire (eTriOuiuLLa, ope^ig)} Desire, as Aristotle employs it,
is not a purely pathic or affective element. Feeling as such
(theoretically) is completely passive, — mere enjoyment of
the pleasant or mere suffering of the painful. Aristotle,
however, describes desire as an effort towards the attain-
ment of the pleasant, i.e. he includes in it an activity or a
conative element. It is feeling with an added quality of
impulse (Trieh). More specifically and in detail the elements
contained in it are : (1) An idea or presentative element.
There can be no desire without cognition or imagination
{opeKTLKov 6e ovK avev (pavraa-Lag).^ An animal cannot desire
that of which it has no image. (2) An element of feeling.
In every desire or aversion there is an element of pleasure
or pain.^ (3) An element of effort or activity.* Desire
involves pursuit or avoidance, and in it is given a spring

J Be an. 4326 6 ff. , 43.Sa 2 ft'. ,4146 5, 433a I— 433/> 30, 43 la 12 ; De somno,
454631; Efh. nir. 1094a 21, 11 39a 22, lllla32tf.
^Deav. 4336 28.

'^De ail. 413623, 434a 3 ; Efh. mc. 1175627.
•^De an, 433a 9-21 ; Eth. nic. 11116 17, 1139a 22.

I'KACTICAI. KKASON AND WILL Ix

of action. Tim object ol* (lesire Ih tli(r motive in conduct.^
The plcaHure that is felt or anticipated is tlie object of (iflbrt
and the initiator ol' movement, and it m throu<(h dcinire
that tlie practical reason operates indirectly on actions.
" Mere reasoning never sets anythint;* in motion, bnt only
reason in tr about means to an end or practical reasoning,"^
i.e. reasoning which guides or modiiies tlie desires.

This deliberative process of the practical reason, issuing
in an imperative conclusion and combined witli desire, con-
stitutes for Aristotle the moral will. The reason alone does
not produce action, and the desire alone is non-rational and
non-moral. Aristotle, therefore, defines the moral will
{Trpoaipecrig)^ as desire penetrated by reason, or reason
stimulated by desire (ope^i^ SiavorjTLKi'i, uovg dpeKriKoiiy
The practical reason contains a jussive force and rightness,
while desire supplies an active, appetitive quality. The
moral will, therefore, is a complex of reason and desire,
a,nd is supposed by Aristotle to function under the follow-
ing modes : (1) deliberate choice ; (2) purpose ; (3) freedom ;
(4) fixed habit. By means of particular acts issuing from
free and deliberate choice is generated the individual's
moral character, which Aristotle describes as fixed habit
(e^ig) ^ or the persistent will.

Aristotle maintains the freedom of the will, and says it
is in our power to be "worthy or worthless."^ This, he
argues, is attested by our own consciousness of power to

1 De an. 4336 1 1 . 2 jui^^ ^ic. 1 139a 36.

•^Eth. nic. 1106a3, ni3allflf., I139a31, 33, 11396 4; De rnot. anim.
7006 23. •* Eth. nic. 1 1396 4, 1 1026 30.

^Categ. 8628, 9a 5; Eth. nic. 1106a 22, 1105625, 11576 31.
^Eth. nic. 1113614.

Ixx INTRODUCTION

do or to refrain, by the common testimony of men, by the
rewards and punishments of rulers, and by the general
employment of praise and blame. Particular acts are
always in our power, and we are responsible for them, —
we may not contend that because they are determined by
temperament or character, they are not free and we are
not responsible.^ " We are masters of our acts from
beginning to end, when we know the particular circum-
stances ; but we are masters of the beginnings only of our
habits or characters, while their growth by gradual steps is
imperceptible, like the grow^th of disease. Inasmuch,
however, as it lay w^ith us to employ or not to employ our
faculties in this way, the resulting characters are on that
account voluntary." ^ In a certain sense we are creators of
our own determinism, paradoxical as this may sound.
Aristotle says in the Topics that man is determined in
the sense that " a man's destiny is his own soul," ^ although
its character is his own voluntary creation. It is true
that by voluntary particular acts a man becomes volun-
tarily just or unjust, " but it does not follow that, if he
wishes it, he can cease to be unjust and be just, any more
than he who is sick can, if he wishes it, be whole. And it
may be that he is voluntarily sick, through living incontin-
ently and disobeying the doctor. At one time, then, he
had the option not to be sick, but he no longer has it, now"
that he has thrown away his health. When you have

^Eth. nic. 11136 5 ff. (Bk. III., ch. 5).

"^Eth. nic. 11 14?) 26 ff. (Peters' translation, 4th ed., London, 1891,
Bk. III., ch. 5, end).

'•' Top. ir2a38, TavTTju (so. ^vxv'') 7^p eKdarov ehai dalfxova.

CRKATIVK HKASON Ixxi

thrown a Htone, it is no lon^i^r in your ])()W(;r to (^all it
l)ack."i

In th(^ foretr()in<^ 1 liavc had rc^^ard only to the moral
will. Jn a general sohhc, however, — perhaps akin to
Schopenhauer'H conception, — Aristotle employs thi^ term
evtpyeia (all organic effort) as will. This form of will or
activity is, in his teleological view of the world, impulse to
the good or a striving towards self-realization, whether in
plant or animal. It manifests itself in psychical life in
such various forms as nutrition, locomotion, sensation, and
rational activity. The whole of psychical or organic life,
therefore, is regarded from the standpoint of will or
activity tending designedly towards the realization of a
given potentiality. But will in the moral sense, the
voluntas intellectiva of Thomas Aquinas and the will of
modern ethics, is rationalized desire or feeling acting under
forms imposed by reason.

VIII.

Creative Reason.^

Aristotle's account of the theoretical activity of reason
is very meagre, — wholly inadequate for any reconstruc-
tion that is not speculative and tentative. Even the
learned commentator Themistius says regarding the
doctrine of the active reason : " The philosopher himself
(i.e. Aristotle) is here more like a puzzled inquirer

^Eth. nic. 11136 14 ff.

2 This chapter is reprinted (with slight changes) from the Philosophical
Review (Vol. XI., No. 3, May 1902).

Ixxii INTRODUCTION

{(iTTopovvTi) than a teacher." ^ And Theophrastus, who
succeeded Aristotle as Scholarch of the Lyceum and was
intimately instructed in the Peripatetic doctrines, although
he accepted the theory of a twofold reason (active and
passive), was unable to explain it. How the reason could
be at once native to man and yet enter from without, and
how potentiality is related to actuality in reasoning, were
difficulties which Theophrastus, as reported by Themistius,^
regarded as serious, if not insoluble. Thus the question
regarding the nature of the active reason^ early became a
matter of controversy, and it has continued a fruitful source
of polemics among the Syrians, Arabs, and Christians for
well-nigh two millenniums.

Eudemus explained the active reason in us by saying
that it is God (not Oelov but Oeo?) in man (cf. Eih. Eud.
1248a 24). Similarljr, Alexander of Aphrodisias (called
Aristotle's exegete par excellence), who held a pantheistic
view of the world, regarded the creative reason as the
activity of the divine intelligence.'* The Syrians and Arabs
were greatly influenced by Alexander. Avicenna, however,
interprets the doctrine in terms of an emanation theory of
the world, akin to Neo-Platonism. Intelligible forms are
endowed with immaterial pre-existence in pure spirits, the
highest created intelligences. From the highest they pass

^ Themistius, Comm. in A rist. lib. de anima, fol. 7 1 b.

•^ Themistius, Paraphrasis librorvm de anima, ed. Spengel, pp. 189, 8 ;
198, 13. (On Deaji. III., 5.)

' The term voOs TroirjriKos occurs nowhere in the writings of Aristotle, but
the equivalent is given in t6 iroirjTiKbv and rb -rrotetv iravTa and by implica-
tion in the antithesis to vom TradrjTiKos. Cf. De an. 426a 4, 430(112,
430a 24.

■* Cf. Brentauo, Die Psychologic des Aristoteles, Mainz, 1867, p. 7.

ORKATIVK KKASON Ixxiii

into a HC5C()n(l .spluu*', IVoin tlui Ni'-cond iiilo a tliiid, and
.so on down into th(^ hist, whicli is tlic cicativi^ rcaHoii
{intelli(je7Ui(t (ujmx). I^'ioni this cicafiNc (cosniic;) nuison
intelli^ibK^ I'oi'ins pass into the soul, on tli(^ one liand ; as
substantial lorins tlicy pass into niatcrial tilings, on tin; otlnji-
hand. Subject and object arc thus icconcilcd by incians
of the forms (intelligible for reason and substantial for
concrete things) wliich emanate from a connnon source, viz.
the creative reason. The substantial form, i.e. tlie class-
notion immanent in sensible particulars, is correlated with
the intelligible form, i.e. the concept inmianent in reason,
and therefore knowing subject and known object are only
different aspects of one reality. Subject and object are
unified in the creative reason. The passive reason, by
means of phantasms or images, is able to apprehend tlie
substantial forms (genera), and from the active reason it
receives the light of intelligible forms (concepts). The
intelligible forms from the active reason are combined in
the passive reason with the sensible forms, and erected into
the structure of empirical science. Every act of knowing
implies receptivity from this dual source of emanated
forms — intelligible and substantial forms : a curious mix-
ture of Aristotelianism with Neo-Platonism.

Averroes, the foremost Arabic exegete of Aristotle, and
one of the most important intellectual figures of the Middle
Ages, regards both the active (intellectus agens) and the
passive reason (intellectus materialis) as spiritual entities
distinct from the body and from each other. The former's
activity consists in making sensible images intelligible, and
thereby moving the passive reason. The passive reason

Ix xi V INTRODUCTION

receives the phantasms which have been illuminated and
made intelligible by the active reason. This dual reason
(consisting of two separate entities) is the eternal in man ;
while the other powers that are concerned with the par-
ticular originate with the body and perish with the body.
In the interpretation of Avicenna, on the contrary, only
the creative reason is eternal ; while the passive reason,
depending on the life of sense-experience, perishes with the
body. In the interpretation of Averroes, although the
reason is immortal, individuality ceases with death; for
differences in individuals are due to differences in their
accumulated sensible images and phantasmata — in the
content of their experience. Rational activity, as such, is
universally the same, and it is 'only this universal, non-
individual principle of reason that persists after death.
All individuals are alike in participating in one rational
life, and they are different in so far as reason has a
different mass of images to illumine. The principle of
individuation is in plavstic matter, not in generic form, and
reason is related to sensible i masses as form is related to
matter.

Trendelenburg,^ in the commentary to his edition of the
De anima, explains the passive reason as the sum of all
the lower cognitive faculties, including the power of
sense-perception. It is passive because it stands in the
relation of receptivity to the object of cognition and is
affected by it. The completion of its processes is, however,
obtained only through the agency of the active reason.
The derivation of the universal notion from particular
* Cf. Commentary on De an. III., § 5, 2 flF.

CHKATIVK RKASON Ixxv

sonsationM is a Fniiciion of iho paHHivc reason, in mo far aft
the universal notion is I't^jrarded as [)ai't of Mie mind's
content. Tlie creative reason furnishes ihii ultimate prin-
ciples of knowle(l<j^c, i.e. it contains and applies the standard
of truth a!i(l falsity in tlu^ conceptual world as the
' connnon sense ' passes jud<i^ment on the true and false in
perceptual reality.^ The creative reason is not the divine
spirit (although it is related to the divine), but belongs tc;
the individual, and is not the same in all men. The rela-
tion betw^een the divine spirit and the creative reason in
man is nov^here explained by Aristotle, beyond his saying
in the Metaphysics that they are analogous principles.^

Ravaisson, in his Essai sur la nietaphysique cC Aristote^
says that the individual man, according to Aristotle, has
only passive reason, which as the potentiality of all forms
and ideas is analogous to primary matter. It is the uni-
versal potentiality in the world of ideas. On the other
hand, the creative activity which actualizes possible forms
and produces all thoughts is the absolute reason. The
sensible and the passively rational are fundamentally the
same ; both exist in a single consciousness, and are operated
on by the active reason. The entire passive reason (and so
all individuality) is mortal. The creative reason is con-
ceived by Ravaisson in the same way as by Alexander
of Aphrodisias. Renan* regards Aristotle's conception of
the creative reason as similar to Malebranche's theory of
seeing things in God, — a conception suggested to Aristotle,
perhaps, by the Anaxagorean doctrine of Nous.

1 Cf. Aristotle, De insom. 4616 2 fF. 2 Metaph. 10726 18 ff.

3 Vol. I., pp. 586 ff. ^Brentano, op. ciL, p. 34.

Ixxvi INTRODUCTION

Zeller considers the passive reason to mean the " sum of
those faculties of representation which go beyond imagina-
tion and sensible perception, and yet fall short of that
higher thought which has found peace in perfect unity
with itself." ^ It does not include the powers of sense-
perception, as Trendelenburg thinks, nor is it identical
with " fancy as the seat of mental pictures," as Brentano
supposes.^ Von Hertling, in calling the passive reason
" the cognitive faculty of the sensitive part," ^ would
almost seem to identify it with the sensus communis.
Zeller rejects these and all other explanations of Aristotle's
theory, and wholly abandons the reconciliation of the
twofold reason in one personality. He further considers
it entirely unjustifiable, even in Aristotle's own theory, to
apply the term nous to the ' passive reason.' Reason, he
says, is in its essence " a single immediate apprehension
of intelligible reality, constituting one indivisible act," *
which it is not possible to interpret in terms of Aristotle's
dual theory.

Wallace, whose interpretation of Aristotle is somewhat
coloured by English Hegelianism, says : " Aristotle would
seem to mean that while our intellectual powers are on the
one hand merely receptive — while they merely elaborate
and, by processes of discursive thought, systematize the
materials of thought — these materials of thought only
become so, only get formed into an intelligible world, by
an act of reason which has gone on from the creation of

' Zeller's Aristotle, Fng. tr., Vol. II., p. 102.

* Zeller, op. cit., II., p. 103. ''Von Hertling, M atone imd Form, p. 174.

* Zeller, op. cit., II., p. 105.

(MIKATIVK KKASON Ixxvii

the world an<l is in turn (MnploycMl by (^acli of uh. Shortly.
tlu'H, ilio creative nelson is thi" faculty vvliicli coiiHtantly
interpretH and, as it were, krv,\)H up an int(^lli^il)le world
Tor experience to operate upon, while the receptive reason
is the intellect applying itsell" in all tlu; various procesHes
whicli iill our nnnds witli the materials of knowledge."^

The fore<^oing account of Aristotl(5's tlieory of reason,
as interpreted by his most notable connnentators, exhibits
very wide differences of opinion. This t^ieat diversity is
due to the character of the data furnished by Aristotle
— data that are both meagre and ambiguous, precluding
the possibility of any apodictic formulation of his doctrine.
There has been no lack of ability or ingenuity expended
on it. It is entirely hopeless, in my opinion, to try to
discover any satisfactory explanation of the creative reason
in the scant}^ passages of the third book of the De anima^
to which attention has been too exclusively directed. An
explanation, if it can be found at all, can be found only in
the light of Aristotle's general system of philosophy, and
more especially in the light of his complete theory of know-
ledge. I shall proceed at once to make my meaning plain.

It is clear that the theory of a tw^of old reason, as Aristotle
held it, originated partly in the controversy regarding the
distinction between conceptual and perceptual knowledge,
and partly in Aristotle's metaphysical ideas regarding the
distinction between form and matter. The controversy
touching conceptual and perceptual knowledge had before
Aristotle's time issued, on the one hand, in the extreme
sensualism of the Sophists, and, on the other hand, in the
^ Wallace, Aristotle's Psychology, p. xcviii.

Ixxviii INTRODUCTION

extreme rationalism of Plato. Between these two Aristotle
adopts a mediating position of empiricism. To him there
are no innate ideas, and no body of rational truth totally
independent of particular reality. All knowledge is per-
ceptually derived, but the materials of perception cannot
be converted into the fabric of scientific knowledge or into
general concepts without a creative and supplementary
act of reason. For Aristotle, as for Kant, conception with-
out perception is empty. The content of perception is
made into conceptual knowledge by a process of reason,
and in this sense is a created content. Before this act
takes place, the content of mind is passive matter awaiting
a transforming and constructive process. At this point,
Aristotle applies to psychical life the metaphysical dualism
under which he views the entire organic world. Active
reason stands to passive reason in the relation of form to
matter.^ His metaphysics, then, and the distinction between
conceptual and perceptual knowledge, explain the genesis
of his theory of a twofold reason. The creative reason is
the form-principle ; the pathic reason is the sum of matter
that is formed into rational significance. Eeason receives
its content from without ; in other words, it is passive.
However, if that were all, reason would be only a receptacle
of sensations, perceptions, memory-images, and phantasmata.
But transcending these pathic elements, reason has the
informing power of changing their potentiality into the
highest abstractions and most general notions and laws.
In this way, reason, in its pathic aspect, becomes or receives
all reality ; while in its active character, it creates all

1 De an. 430a 10 ff.

CRKATIVK KKAHON Ixxix

reality hy bostowin<^ iij)()n it a lational form. Without tho
latter the mind would he a ma.sH of particulars, of unrelated
manifold tliini^H, blind. Th<' active reason creat(^H an
intellit^ible world in the Henwe of couHtructin^ itw intc^llif^i-
bility, while its real content is ^iven in the materials of tlie
passive reason which are delivered from without. This
content is potentially conceptual. The creative reason is
thus prinuirily without content, an unwritten tablet.^
Between conceptual and perceptual knowledge, between
the abstract and concrete, there is not for Aristotle the
great impassable gulf that we find in Plato's epistemology.
Although the discovery of the universal is an act of reason,
yet the universal is potentially and immanently in the
individual. The subject-matter of reason is the immanent
universal, which in a certain sense is in the mind itself.^
Thought and sense-perception are neither identical nor are
they to be completely sundered. Aristotle sharply criticises
both of these extremes in his predecessors, holding the
sophistic sensualism and Platonic rationalism to be equally
one-sided and erroneous. In thought we think, it is true,
what is potentially given in perception, and yet this object
of thought must first be made rational by a creative act of
reason. Reason creates its world in terms of itself (i.e. a
rational world) : and, as its subject-matter consists of
abstract ideas, it thinks itself, and subject and object are
identical.^ Aristotle is not a pure empiricist, although in
certain passages he speaks as if all our ideas were derived
from sense-perceptions* and apart from sense-perception

1 De an. 430a 1. ^ De an. 4176 23.

3 De an. 429a 25, 430a 2, 4316 17. * De an. 432a 2 ff.

Ixxx INTRODUCTION

there were no reality. In the Analytics, however, where
he gives the most detailed account of the origin of our
knowledge, he speaks of the highest principles of knowledge
as immediate {ra a/uLea-a) and as presupposed by mediately
derived knowledge, being the latter s starting - point.^
These ultimate principles are propositions whose predicates
are given in the subject, i.e. ' analytical a priori judg-
ments.'^ This knowledge is, however, merely potential
(empty conception) until applied to the content of experi-
ence. It does not contain any positive ideas, but, as in
the case of the principles of contradiction and excluded
middle, it comes to consciousness in the regulation and
determination of cognitive data. These regulative, axiomatic
principles are formed by the mind out of itself.^ The
content of the concepts arrived at by induction, or by an
ascent from particular to general, takes the form of mediate
knowledge ; and the most universal of these concepts is
only a " precipitate of a progressively refined experience,
and is due to the last act in successive generalizations upon
a matter given in experience." * Ideas derived from in-
duction attain a degree of certainty not higher than the
source from which they spring. On the other hand, the
ultimate principles (apxa^) oi reason are necessarily true,^"'
and such knowledge has the nature of an " intuition as
contrasted with sensible perception." ^ The apodictic
syllogism, or highest form of scientific truth, proceeds from

'Cf. Zeller's Aristotle, Eng. tr., Vol. I, p. 197. Also Aristotle, AiiaJ^
post. 86^36, 94a 9, 108/>8; Eth. nic. 1141a.

2Zeller, op. cit.. Vol. I, p. 198. '^ De an. 429&28 flF.

^Zeller, op. cit., Vol. I, p. 201. -^Aristotle, AnoU. post. 100^)5 ff.

«Zeller, op. cit., Vol. I, p. 202.

CRKATIVK REASON Ixxxi

these ultimalo piinciplcs as prciiniHHeH. Induction, proccjcd-
ing from the particular, i.s chwircr to uh lx3cauHo individual
thintT^s of sense liave more ap])ar('iit certainty. Deduction
and induction i'orin the component elements of scientific
method, hut the function oi' the former is liitrher, heing
the interpretation of phenomena by the ultimate principles
both of knowledtjje and existence, viz., by universal laws
and causes.

Ultimate principles and universal forms are immanent
both in the mind and in things. They are not mental
categories projected upon the phenomenal world, but are
discovered in the phenomenal world by reason. In a sense,
reason finds itself in the world, and the fact of this im-
manent community bridges the gulf between subject and
object. On the plane of perceptual knowledge, the passage
between subject and object is bridged by the function of
the central sense, which is the active principle in converting
received sensations into a conscious percept. The content
of the central sense — memory and phantasy — as the pathic
material of reason, is in turn converted into the form of
conceptual knowledge by the creative activity of reason.
Reason has no bodily organ, and so operates only on
psychical elements, and not on elements physiologically
mediated. Reason, then, confers on a potentially rational
world its actually rational existence ; and, moreover, in
thinking the actually rational, it thinks itself. Without
the active reason the conceptual world would be no more
known in thought than the visible world would be seen
without light.^ As light makes colour visible, so the

^ m an. 430a 15.

/

Ixxxii INTRODUCTION

creative reason makes the the universal forms intelligible.
Or, to use another analogy employed by Aristotle, the
creative reason operates on the content of perceptual con-
sciousness as an artist operates on his raw materials.^ The
two main stages in the process of knowledge, perception
and conception, are supplementary. Thought, on the one
hand, requires a sensuous image,^ and perception, on the
other, remains on a brute level when not illuminated and
elevated into conceptual form by reason.

The creative reason is akin to the divine. Corresponding
with his metaphysical conception of the divine in the
universe, Aristotle regards the creative reason as the divine
in the microcosm. It is no part of the entelechy of the
body, but is transcendent (x'^P^^'^^^' '^•^- ^^ ^^^ ^^ bodily organ
and is separable from organic life) and it enters the body
from without (OvpaOep).^ It acts, however, on the rational
life of the organism, but it acts as the ' unmoved mover,*
who is immanent in the world without being a part of it.
The creative reason is not developed with the body, but
enters the psychical element (whose immediate corporeal
embodiment is the warm air or pneuma in the seed) at the
moment of conception. Conception is the occasion, not the
cause, of its entering into the womb.* The question, how-
over, touching the preexistence and immortality of the
soul is scarcely more than mentioned by Aristotle, and,

1 De an. 430a 12. ^De. an. 431a 17, 432a 8 ; De mem. 4496 30.

^ De gener. anim. 7366 27 ff.

■* De gener. anim. 737a 5 ff. Granger in a valuable article in Mind (Vol.
18, New Series, Vol. 2, 1893, p. 317) thinks that a universal reason in
Aristotle's psychology can be spoken of only in the sense in which one
speaks of "a universal humanity." Of. the same writer in the ClassiccU
Review, Vol. VI., pp. 298 ff.

CKKATIVK HKASON Ixxxiii

indeed, it lianlly i'alls within tho .scope of hi.s psychology,
which is an essentially bioloi^ical discussion. It is ordy in
treatin<^ of the nature of reason that he goes Ixiyond the
boundaries of empiricism and makes concession to the
traditional view of the divine origin of the noetic power —
a concession that may have been prompted by liis analo-
gous view of the Prime Mover as the transcendent cosmic
reason. Aristotle constructs his psychology, a.s he does his
entire system of philosophy, on the basis of the deliverances
of the special sciences of his day — deliverances which were
penetrated and interpreted by his unifying and organizing
spirit. As Romanes says, " instead of giving his fancy free
rein ' upon the high a 'priori road,' he patiently plods the
way of detailed research."^ Yet, after he has completely
examined the data and psychical mechanism of empirical
knowledge, he finds them inadequate to explain the w^hole
of reality, and is forced to introduce a rational ego to
explain the potential rationality of pathic experience.
This noetic principle which rationalizes experience is in no
wise connected with the physical organism, 'and as it is
not a part of the latter's entelechy, so it does not perish
with its dissolution." It is the a 'priori condition of all
rational knowledge, and, as such, it is not individual.
Receptive or pathic reason,^ on the other hand, is simply

1 Contemporary JRevieiv, Vol. 59, p. 284. '^ De an. 4086 18, 4136 20 S.

^ No one familiar with Aristotle's use of terms, will discover an objection
in his applying two designations to the same thing, viz. to his calling the
sum of perceptual experience now sensiis communis, and again passive
reason. For as completed sense-experience, the sensiis communis is form
(eI5os), and as the raw material for some higher development it is poten-
tiality (CX77). That higher development is reason, which the common
sense is potentially.

Ixxxiv INTRODUCTION

the life of sensation as a potentially rational mass, and is
connected with the physical organism, with which it
perishes.^ Primarily, the creative reason is, as above noted,
without content ; it is an unwritten tablet (ypa/uLjULaretov).^
Its content is given in the passive reason, which is stored
with phantasmata ultimately derived from sense and the
free construction of imagination. Strictly speaking, the
active reason does not think things, it does not create de
novo; it merely interprets things, or rationalizes pheno-
mena, by its spontaneous activity.^ Nevertheless, we have
here not merely that which is given in sense-experience,
but a new element, rationally derived, a new significance.
Passive reason rises no higher than the deliverances of
sense-perception and their re- wrought form in memory and
phantasy. The sum of these is the sum of the content of
the sensus comonunis ; this sum, regarded as potentiality, is
the passive reason, on which the active reason operates in
the creation of a rational and conceptual world. The
creative reason does not, indeed, think anything apart
from the passive reason,* because without images derived
from experience thought has no content and nothing to
interpret or illumine. Its activity, however, is continuous,^
because its subject-matter, unlike a sense-object, is always
present. Further, as the universal reason, it is as eternal
and continuous as is the intelligibility of the eternal world.^

J De an. 430a 25. 2 j)^ ^n. 430a 1 .

^Cf. Scotus : " nullus intellcctus intcUigit, nisi intellectus possibilis. . . .
[intellectus agensj non iutelligit, sed intelligeie facit." Quoted by Schlott-
mann iii Das Vcrgdngliche und Unvergdngliche in d. menschlichen Seele
iiach Arist. p. 48.

■» De an. 430a 25. ° De an. 430a 22. « De ccdo, 2796 12.

CKKATIVK RKASON Ixxxv

Wo do nol. r('iii(Miil)i;r ' tho procoHH(5H ol' the; active retiHori —
an uiidcrHtandiii!^ oT wliicli in (lie indi\ idual is arrivcil at
only by analysis — hocauHu it is without })assivity, and
nieinory ia a passive power.

Aristotle describes the criuitive reason (1 diaw IVoni
various passa<j^es) as follows : it, is uinnixed, transcendent,
passionless, oi' divine nature, it suffers no change, is not
born, it has no bodily organ, enters the body from without,
and is inimortal.'- I'he (iU(\stion ol* the reason's transcend-
ence and innnortality, although metaphysically interesting,
has little epistemological significance, and Aristotle scarcely
does more than raise the question, and while he espouses
the view of transcendence and immortality, he does so
hesitatingly and without dogmatism. Transcendence, in-
deed, would seem to have no legitimate place in his
biological view of the soul and to be irreconcilable with
his definition of yjrvx>} ^^ " entelechy of the body." It is a
survival of the Platonic transcendentalism, with which
Aristotle had been imbued during his life in the Academy,
and whose spell he never quite shook off, — a thing to be
set down to his credit.

In the foregoing account of Aristotle's theory of reason
I have endeavoured to show how his employment of the
terms * form ' and ' matter ' and his criticism of the
Socratic-Sophistic controversy regarding conceptual and
perceptual knowledge can be made to supplement certain
dark passages in the De anima and the Analytics, and how

1 De an. 430a 23.

-i)e an. 408618-29, 413624, 430a 12 ff.; Eth. nic. 1177a 15; Be gen.
anim. 736615 ff.

Ixxxvi INTRODUCTION

these various elements can be combined into an intelligible
and consistent interpretation. Briefly summarized, this
interpretation is as follows : Aristotle adopted a mediating
position between the ultra-sensualism of the Sophists and
the ultra-rationalism of Plato. The totality of knowledge
is neither purely empirical nor purely rational, but a com-
posite (orvvoXov, as is every other combination of ' form ' and
'matter') of sense experience and rational activity. In this
composite, rational activity is related to sense-experience as
elSog is related to vXrj. The sum of sense-data constitutes the
potentiality of reason, i.e. it constitutes the passive reason,
while their construction into actual rational significance
constitutes the activity of creative reason ; the real content
is given in the former, the formal content in the latter.
The content, therefore, of the sensus communis regarded as
rational potentiality is the vovg TraOrjTLKo^ ; the power which
converts this potentiality into actual rational forms or
meanings is the vov? irotrjriKog. This conversion is identical
with the erection of perceptual materials into a world of
concepts and laws. The subject-matter of reason is an
immanent universal, — immanent at once in perceptual
reality and in the reason itself. The process which the (
reason undergoes in discovering the universal is, therefore, i
the process of finding itself in the world. The conception
of an equivalence between the universal forms existing in
the mind and universal forms immanent in nature bridged
for Aristotle the gulf between subject and object, — two
aspects of reality which he regarded as formally identical.

ABBREVIATIONS.

[ ] = words regarded by Biehl as not belonging to the text and to
be deleted.

([ ]) = words inserted by the translator.

The marginal references, e.g. 402a, are to the pagination (with column
a or b) of the Berlin (quarto) edition. The other marginal references, e.(j.
2, 3, 4, are to the sections in the chapters of the Oxford (octavo) 'edition.

ARISTOTLE'S PSYCHOLOGY.

(DE ANIMA.)

BOOK THE FIRSIV

CHAPTER I.

We regard knowledge as a good and precious thing, but 402 a
we esteem one sort of knowledge more highly than

* Bonitz regards the various chapters of De an. Bk. I. as Aristotle's,
although he thinks that the order in which they are placed is due
to another hand {Monatsberichf der Konigl. Premiss. Akad. d. Wiss.,
1873, p. 481). The authenticity of Bks. I. and II. has never
been seriously questioned. Bk. III., however, was held by Weisse
to be spurious {Aristoteles von der Seele, pp. 278 ff.), but no scholar
now, to my knowledge, accepts his view. The Aristotelian canon
is much less questionable than the Platonic, and, as far as the
acroamatic writings are concerned, has always remained compara-
tively fixed. The objection of Bonitz to Bk. I. scarcely means
more than that its Aristotelian content was subjected to editorial
arrangement, which was not always skilful, — a criticism that may be
applied to every other treatise in the Opera. To attempt to determine
how much latitude Androuicus and the succeeding editors allowed
themselves, is merely to speculate. All of the works, without exception,
are fragmentary and ill put together, but this has been explained
generally by the time-honoured hypothesis (and still the most reason-
able one) that the writings of Aristotle, as we have them, are lecture-
notes or perhaps sketches for treatises, which he never put into
finished form, the last part of his life being disturbed by quasi-
religious persecution and spent practically in exile.

A

2 ARISTOTLE S PSYCHOLOGY de anima

another either because of the acumen ^ required for its
discovery, or because it is concerned with better and
more admirable objects : for both these reasons we
should rightly assign the investigation of the soul ^ to the
first rank. Further, it is supposed that a knowledge of
the soul has an important bearing on all truth, and par-
ticularly on that of the natural world. For the soul is,
2 as it were, the genetic principle ^ in living things. Our

^ This meaning of /car' aKpi^etav appears to be the only one admissible
in the context. Cf. Passow, suh voc. The meaning which the term
has when applied to metaphysical or abstract subjects {Eth. nic. 1141a
16; Metaph. 982« 25, 1078a 10; Anal. post. 86a 17), viz., 'exacti-
tude ' in the sense of ' finally true ' or truth deduced from the first
principles of reality, is not applicable here. Aristotle regards the
materials of psychology as belonging to the natural and organic world,
which to him is never the realm of necessary or exact truth. 'Aicpt/Seta
in the ordinary sense of ' precision ' is ascribed to the mathematical
disciplines in varying degrees {Met, 1053a 1, 995a 15; Anal. post. 87a
35), but this sense is also inadmissible here (cf. 402a 11). In addition
to those meanings which refer to the science itself, the word also has a
signification which refers to the demand made by the science on the
investigator, viz., 'painstaking accuracy,' or 'acumen' (' Scharfsinn,'
Passow). In the present passage this appears to be the only usable
meaning. Vid. Wallace, Aristotle^ s Psychology^ p. 196 ; Trendelenburg,
Arist. De an. 2nd ed. p. 156.

^i^vxv ('soul,' 'life,' 'mind,') is generally translated in the following
pages by 'soul.' For a discussion of its meanings in Aristotle's
writings vid. Introduction, Chap. i.

^ 'Apxv {principium) is included amongst the notions defined by
Aristotle in his philosophical dictionary (Metaph. Bk. V.). Through
him it became a philosophical term of the first importance, and has con-
tinued so to the present time. In the sense of element {(ttoix^lop) we
find it in use as early as Anaximander. The meanings enumerated in
the Metaphysics are: In reference to (1) space and time = beginning ;
(2) methods elementary steps in learning; (3) the physical = basis ; (4)
the genetic = the moving cause; (5) the political = primary authority;
(G) knowledge =^mct^mm cognoscendi, as e.g. the premises of a
syllogism. The scholastics included these several meanings under
principium essendi and principium cognoscendi, for which Aristotle has the
corresponding expression, tow 7vw»'at Kal rrjs Kivrjaciai dpxv {Met. 1013a 22).

liK. I. oil. I. MKTIIODS OF INVESTKJATION 3

aim is to investi<,'at(j and ascertain the essential nature
of the soul, and, secondly, to discover those properties
which attach to it as accidents. Certain of the latter
are supposed to be conditions peculiar to the soul's own
nature, and others are thought to be effects produced in
living beings by the soul's agency.

Now, it is altogether the most difficult problem 3
to arrive at any fixed belief touching the soul. From
the fact that the problem is one which is common
to other subjects — I mean the problem of finding the
essence and real definition ^ of a thing — it might perhaps
appear to some that there is a single scientific method
which applies to everything whose essence we wish to
discover, as deductive proof applies to accidental pro-
perties. We shall, therefore, be obliged to make inquiry
into this question of scientific method. But if there is 4
no single and general method which applies to the
ultimate nature of things, our investigation becomes in
that case all the more difficult. And even if the
question of method were cleared up, whether its form
be that of deductive proof, or analysis, or some other
procedure, there still remains a question of great diffi-
culty and uncertainty, viz. from what principles are
we to start our inquiry ? For different principles are
employed in different subjects, as e.g. in numbers* and
in plane surfaces.

The first necessity, perhaps, is to determine under 5

^ For the meaning of rb tL ian see Schwegler's classic excursus in
his Die Metaphysik des Aristoteles, Bk. IV., pp. 369 ff. Also Trendelen-
burg in Rheinisches Museum, 1828, pp. 457 ff.

^ The different principles employed by arithmetic and geometry are
the unit and extension.

4 ARISTOTLE S PSYCHOLOGY de anima

what genus soul is to be classified and what its nature is
— I mean by this the question whether it is an individual
thing and self-subsisting entity, or whether it is a quality
or a quantity or classifiable in one of the other cate-
gories ^ already enumerated, and further, whether it is a
potentiality ^ or rather an actuality. For this makes no
402^ slight difference. "We must also inquire whether the

6 soul is divisible or whether it is without parts ; whether
it is an entirety of one sort or not. And if it is not of
one sort, we must further ask whether the differences are
specific or generic. For nowadays the men ^ who discuss
and investigate the soul appear to direct their inquiries

7 merely to the human soul. We must take pains to see
whether there is a single definition that applies to the
soul, just as e.g. there is a single definition that applies to
animal, or whether a different definition is required for
each kind of soul, just as a different definition is required
for horse, dog, man, god, and we must further inquire
whether the common notion ' animal ' ^ either is nothing

1 The categories or forms under which Being is known, are enumerated
in the Topica [lOSb 22) as follows : L Substance, 2. Quantity, 3.
Quality, 4. Relation, 5. Place, 6. Time, 7. Position, 8. Possession, 9.
Activity, 10. Passivity. All of them are reducible to subject {bvofia,
corresponding to the category of ' substance ') and predicate {prjfxa,
corresponding to the nine remaining categories).

2 For an explanation of the terms potentiality and actuality vid. note
1, p. 42.

^It is not known to whom reference is made here. Simplicius
{Comment, in lib. De an. ad loc.) thinks the Timaeus is referred to,
which is hardly possible owing to Plato's treatment of the world-soul.
Nor is it easy to see how Wallace (translating vvv fxh by "at present "
as he does), can suppose the reference is to the older physiologers.

*The question as to the nature of universals, which divided the
Mediaeval Nominalists and Realists, was here clearly raised by
Aristotle. Vid. Simplicius, Commentary ad loc.

UK. I. en. 1. MK/niOI)S OK INVESTKJATION 0

at all or olsc comes into oxiHtenco only {il'ter tlio indi-
vidual,— a ([uestion that nii^dit (upially well bo raised
regarding any other genenil notion. IF, however, there
are not several souls, but only parts of a single soul, then
the further question arises whether we should examine
the soul as a wliole before we examine the parts. It 8
is also hard to determine which of these parts is in
its nature different from the other and whether we
should first investigate the part or the part's function,
e.g. whether we should first investigate the process of
thought or the faculty of thought, sense-perception or
the organ of sense-perception ; the same question applies
to other cases. Now, supposing that the functions take
precedence of the faculties in the order of investigation,
a further question might arise here as to whether the
complements of the faculties should be investigated before
the faculties themselves, e.g. whether the investigation of
the sensible object should precede the investigation of the
sense-organ, and the object of thought precede the faculty
of thought. Not only does the knowledge of the 9
essential nature of a thing seem to be helpful towards
the understanding of the accidental nature and properties
of substances, just as in mathematics the knowledge of
the essential nature of straight or curved or of a line
or surface is helpful in understanding how many right
angles are contained in the angles of a triangle, but
conversely, the knowledge of accidental properties con-
tributes largely to the understanding of what a thing
essentially is. For when we are able to give an
account of the accidental properties of things, as we see
them, — either of all these properties or of most of them,

6 Aristotle's psychology deanima

— then we are best able to speak also of their essential
nature. For the essential nature is the true starting-
point in all deductive proof. And so in the case of
definitions where not only no knowledge of the accidental
properties is furnished, but where it is not easy even to
403 a conjecture what these properties are, it is evident that
all such definitions are framed after the fashion of
dialectics ^ and are void.

10 A further difficulty presents itself regarding the
affections of the soul, viz. whether all these affections
are common to the soul and to the body which contains
it, or whether there is a something that is the exclusive
property of the soul. And it is necessary, though not

11 easy, to solve this difficulty. In most cases the soul
apparently neither acts nor is acted upon independently
of the body, e.g. in the feelings of anger, courage, desire,
or in a word in sense-perception. Thought, however,
appears to be a function which more than any other
is the exclusive property of the soul. But if thought
is a sort of representation in terms of a sense-image, or
is impossible without this, then even thought could not

12 exist independently of the body. If, then, there were
any function or affection of the soul that were peculiar
to it, it would be possible for the soul to exist separate
and apart from the body.^ If, however, there is nothing

^ I.e. distinctions thus made are merely verbal or eristic and have no
real content.

^ The difl&cult question as to whether the soul is capable of existing
separately from the body is not very clearly or definitely answered
by Aristotle. According to Aristotle's classic definition, the soul is
the " entelechy of a body endowed with the capacity of life." From
this definition one would conclude that the soul cannot exist apart from

BK. I. (ui. I. .SEPARARTUTY OK TTFK SOUL 7

which is ita exchisivo proptirly, it (lannot oxiHt apart, but
the case is siinilar to that of a Htraij^^ht lino, wliich, as
straight, has many properties, e.rf. contact with a bronze
jjflobe at a given point, although the ([uality ' straight,'
apart tVoni some body, does not touch the globe. For
it has no abstract existence, as it is always conjoined
with some body. The same thing seems to hold good 13
of the properties of the soul : courage, gentleness, fear,
pity, audacity, also joy, love, hate ; they are all associated
with the body. For along with these psychical con-
ditions the body is also somewhat affected. A proof 14
of this is the fact that sometimes when great and
palpable misfortunes have befallen a man, he is not at
all excited or moved to fear ; on the other hand, one is
sometimes aroused by slight and insignificant mishaps,
and then the body swells in rage and is in the same
condition as when a man is stirred in anger. But this
statement receives still more support from the fact that
when nothing has happened which could awaken fear,
men exhibit those emotions which characterize a man
in fright. And if this is true, it is evident that the 15

the body, although it is not itself corporeal. It is that which gives
to a particular body its individuality and meaning, and it consists of
the following elements : power of nutrition, self-movement, sensation,
memory, emotion, imagination, and reason. Amongst these functions
of the soul, reason is peculiar to man, although reason in its passive
form is based on sensible experience and is conjoined with the life of
the body. There is, however, a further form of reason, which Aristotle
characterizes as active reason (i^oOs iroLif]Ti.Kbs), whose existence is entirely
separable from the body, and is immortal {De an. 403a 23). This form
of reason is concerned with intuition or immediately apprehended
truth, while the passive reason is occupied with mediated truth. There
seems, however, to be no place for the former in Aristotle's definition
of the soul cited above. Cf. Introduction, On the Active and Passive
Reason.

8 Aristotle's psychology deanima

emotions are ideas which find expression in the body.
So that we have, for example, such definitions as the
following : " Anger is a kind of movement of such and
such a body, or part, or faculty, under this or that
stimulus and due to this or that motive." It is for
this reason that the study of the soul belongs to the
province of the natural philosopher, either the soul in its
entirety or such part of it as has to do with the body.
i6 But the naturalist and the speculative philosopher would
frame their definitions severally from different stand-
points. For example, in reply to the question " What
is anger ? " the speculative philosopher says it is the
desire of retaliation or something of that sort, the
naturalist says it is the seething of the pericordial blood
403 b or heat ; the one has furnished in his answer the matter,

17 the other the form or reason, of the thing. For the
notion is the form of a thing, and it is necessary that
this notion be embodied in a particular matter, if it is
to exist. For instance, the notion of a house is that
of a shelter, to protect us against injury from wind and
rain and heat ; the natural philosopher, however, will
call it stones and bricks and wood, while the other
grasps the notion embodied in these things and for which

18 they exist. Which of these, now, is the real physical
philosopher ? Is it the one who busies himself with
the matter, but is ignorant of the notion ? or is it the
inquirer who is occupied with the notion alone ? I
answer, it is rather the man who combines both of
these characters. But what is the genius of each of
these two men ? Surely there is nobody who concerns
himself merely with the properties of matter that are

i.K. I (11. I. Hh^LATION OF SOUL TO HODY 9

insi'jwinihli'. iiiul iiuirtily us iiisopjirahlu ; huL the ijliy.sical
pliiloso})h(T lias to do with all tho functions and (qualities
of body and matter which are of such and such a kind.
Such properties as are not subject-matter for the natural
philosopher, are dealt with by someone else, in certain
instances by a professor of one of the arts, perhaps, as
e.g. by a builder or by a physician. But in the case
of properties which are inseparable, although they attach
to no particular body and may be abstractly regarded,
with these the mathematician is concerned ; and in 19
so far as the qualities are regarded as abstract or
transcendent entities, the metaphysician is concerned
with them. But we must now return to the point from
which our discussion digressed. We were saying that
the properties of the soul do not exist apart from the
physical matter of living things, in which such qualities
as courage and fear are expressed, and are not to be
regarded as a line or surface.

CHAPTER II.

In our inquiry into the soul it is necessary for us, as we
proceed, to raise such questions as demand answers ; we
must collect the opinions of those predecessors^ who
have had anything to say touching the soul's nature, in
order that we may accept their true statements and be

2 on our guard against their errors. The initial step in our
inquiry will be to set forth those attributes which are
currently supposed to inhere in the soul's nature. Ani-
mate nature is thought to be different from the inanimate
mainly in two particulars, viz. in movement and sense-
perception. And these, I may say, are the two
traditional characteristics of the soul which we have
received from earlier writers. Some of these writers,
indeed, affirm that motion is the first and foremost
characteristic of the soul, and in the belief that what is
itself unmoved cannot impart motion to anything else,

3 they suppose that the soul is a moving entity. This
404 a is the reason why Democritus declares the soul to be a

sort of fire or warm element. He asserts that, although

* Aristotle begins here the first extant history of psychological

opinion.

10

UK. I. (II. II. IIISTOKV OF rilKOHIKS 11

iitoiiiic structures an* inliniLr in vari(;ty, both fin; aiul
soul arc coiujioscd ol" Hplicrical atoms, similar to tIk;
particles, as wi^ call (hem, sim-h in flic air wlatn sun-
bcauis stream tliroii^li a doorway, iiiid these atoms, as
collective seed-particles, he calls the elements of the
universe. Leucippus also holds a similar view. Tt is the 4
spherical atoms, he says, that constitute the soul, because
such forms can most easily penetrate through everything,
and, bein«j: themselves in motion, can move everything
else, the theory of these philosophers being that the soul
is the principle which imparts motion to animals. It is 5
for this reason too that they regard respiration as the
function that fixes life's limit. They think that the
surrounding air presses together and expels the atomic
bodies, which, because they are themselves never at rest,
impart motion to animals, but theit relief comes through
respiration, because similar particles thereby enter into
the body from without. These latter, by restraining the
contracting and condensing element, prevent the spherical
atoms which are already in animals from being entirely
expelled. So long as they can do this, life continues.
The theory which has been handed down from the 6
Pythagoreans appears to have the same import. For
some members of this school maintain that the sun-motes
in the air are the soul; others declare that the soul is
the principle which sets these in motion. They refer to
these particles in their theory, because the particles
appear to be in constant motion, even when there is a
complete calm. The philosophers who regard the soul
as a self-moved principle come to the same conclusion.
For they all seem to regard motion as the most char- 7

12 Aristotle's psychology deanima

acteristic attribute of the soul, and while everything else
is moved by the soul, the soul is self-moved. They came
to this conclusion because they observed that nothing
sets anything else in motion without being itself in
motion. In a similar spirit Anaxagoras also declares the
soul to be the principle of motion, and this view is held
by such others, if there are any, as assert that Keason
sets the All in motion.^

Anaxagoras does not, however, quite agree with Demo-
critus. For Democritus absolutely identifies soul with
reason, and considers truth to be that which appears
to the senses. Consequently, Homer is right in singing
of Hector that he lay " thinking awry." ^ Democritus

^ The pre- Aristotelian definitions of the soul here cited are classifiable
into three main groups: (1) those that regard the kinetic or motive
attributes of the soul as its fundamental characteristic ; (2) those that
regard the intellectual and cognitive attributes as fundamental ; (3) those
that attempt to combine these two elements of activity and knowledge.

2 No such reference as this is to be found in our present text of
Homer, although the term dWocppoveopra occurs in II. xxiii. 698. Cf.
also Ar. Metaph. iv. (iii.) 5. 10096 28. The word is here employed in
the meaning of 'to think incorrectly,' while ^poveiu signifies, when con-
trasted with dWocppoueiy, 'to think correctly.' Hector lies senseless
from a blow, and as thought, in the psychology of Democritus, origin-
ates in sensation, his thinking cannot be true, but is paralyzed or per-
verted proportionately to the disturbance in sensation. Error and
mental disturbance {d.X\o<ppopeiv) are explained by disturbance in the
activity of the senses (cf. Siebeck, Oeschichte der Psychologic, Th. i.
Abth. i. p. 129 ; Natorp, Forschniigen zur Geschichte des Erktnntniss-
2irohlemes im Alter thum, pp. 171 ff. ). Democritus makes a distinction,
however, between the relative values of rational and perceptual know-
ledge, between \6yos and atadrjats, although both originate in external
stimuli. The ultimate, and in this sense the real, nature of things is
not discoverable by the senses, but only by rational thought. The true
nature of the world consists of atoms and the void, and these are known
not to our senses, but to our reasoning mind ; they are vorp-d. The
data, however, for these rational truths are to be sought in the deliver-
ances of the senses.

iiK. 1. cii. II. THKOKY or KMPKIUXJLKS 13

(JooH not (Miiploy rtMison as a Hj)ecific. faculty for the
apprelionsion of triitli, luit asserts that houI and rea«oD
are identical, Anaxaj^oras, however, i.s hjss clear on 9
this point. lM)r althoiij^h he says in many passages 404^
that reason is the cause of llic iM'autiful and the; true,
in other passaf^^es he says that reason is the same as
the soul, for it is found in all animals, j^reat and small,
high and low. Reason, however, in the sense of intelli-
gence, is not found equally in all animals, nor even in
all men.

Such philosophers as fix their attention on niove- 10
ment as the main fact in animate creation conceive ol"
the soul as the most mobile principle. On the other
hand, such philosophers as emphasize the knowledge
and perception of reality, define the soul as the
principle of things, some holding there are several such
principles, others that this psychical principle is the only
one. Empedocles, for in^stance, regards the soul as com-
posed of all the elements, and he asserts that each of
these elements is a soul. He says :

" Earth we apprehend by earth, water by water,
And air divine by air, destructive fire by fire,
And love we know by love, sad hate by hate."

In this way, too, Plato in his Timaeus^ constructs n
the soul out of the elements; for we know like by like,
and things are composed of elemental principles. A
similar theory is given in his Discourses on Philosophy ^^

1 Timaeus, 30 C, 35 A, 39 E.

^No such work of Plato is known to us, and the reference is pro-
bably to the oral discourses held by Plato in the Academy. Vid.
Bernays, Die Dialoge des Aristoteles, p. 170 ; Heitz, Die verlorenen
Schriften des Aristoteles, p. 180 ; Zeller, Phil. d. Griechen, Th. 11.
Abth. ii. 3te. Aufl. p. 64, note.

14 Aristotle's psychology deanima

where he defines an animal, regarded absolutely,
as a structure derived from the idea of unity and the
primary elements length, breadth, and thickness ; other

12 things are similarly fashioned. Again, in a different
way, Plato defines reason as unity, and science as two ;
for the latter moves towards unity in a single course. He
also defines opinion as the number of a plane surface and
sense-perception as the number of a solid. Numbers
were declared to be the actual forms and first principles
of things and to be composed of the elements. But
things are discerned partly by reason, partly by science,,
partly by opinion, and partly by sense-perception.

13 Numbers, however, are the forms of things. Since
the soul was regarded by these Platonists as at once
the principle of motion and the principle of knowledge,
some of them included both these ideas in their
definition, and explained the soul as a self-moving
number.^ These philosophers differ, however, in regard
to the kind and number of their principles. The most
far-reaching difference is that between the philosophers
who regard the elements as corporeal and those who
regard them as incorporeal. There are others who define

405 a the elements as a composite of corporeal and incorporeal.

14 They differ also in regard to the number of the elements,
some believing there is one only, and others that there are
several, and their definitions of the soul vary with their
theories of the elements. Amongst the primal elements
they classified, not unreasonably, the principle of inherent

^ Xenocrates of Chalcedon (396-314 B.C.), successor of Speusippus
as vScholarch of the Academy. Vid. Ueberweg-Heinze, Grundriss d.
Oeschichte d. Philosophies Th. i. p. 191, Sth ed.

HK. 1. (11. II. TIIMOKY OF DKMOCKITUS 16

movement. And ho .some philosopherH held the houI to
bo tire; for lire is the finest ami most nearly incorporeal
of all the elements, and furthermore, it most readily
receives and imj)arts motion. Democritus has explained is
in a very neat way the cause of these phenomena. Soul
and reason, he says, are identical, and belong,' to the
primary and indivisible bodies, and are, furthermore, the
principle of motion by virtue of their particles and
atomic forms. Amongst these atomic forms, he regards
the spherical as the most easily moved, and says that
reason and fire are of this sort. Anaxagoras, on the i6
other hand, appears to say that the soul and reason are
different, as we remarked above, and yet he employs
them as essentially one, except that he regards reason as
more than anything else the initial principle of the
world. At any rate he asserts that reason is the only
entity which is absolute, unmixed, and pure. But he 17
ascribes both attributes of knowledge and motion to the
same principle, affirming that reason sets the universe in
motion. Thales also, according to the traditional stories
of him, appears to have conceived of the soul as a sort of
kinetic principle, if it be true that he said the loadstone 18
has a soul because it moves iron. Diogenes, however,
and certain others say that the soul is air, in the belief
that it is the finest element and the ultimate principle.
It is for this reason, also, that the soul knows and
produces motion. On the one hand, it knows by
virtue of the fact that it is primary and other things
are derivatives from it. On the other hand, it is
the principle of motion by virtue of its being the first
element. Heraclitus, also, says the soul is the first 19

16 Aristotle's psychology deanima

principle, since it is fiery vapor from which every-
thing else is derived. It is also the most incorporeal of
all the elements and is in constant flux. We apprehend
that which is moved by what is in motion, and he
believed, as did most others, that the real world is in

20 motion. Alcmaeon,^ too, appears to have held views of
the soul very similar to these. For he says the soul is
immortal because it is like the Immortals, and this
property of immortality belongs to it by virtue of its
perpetual motion. Now, all divine things are in

405^ perpetual motion, — moon, sun, stars, and all the heavens.

21 Certain cruder thinkers, like Hippo, asserted that the
soul is water. They appear to have based their belief
on the nature of animal seed, which in all cases is moist.
Hippo confutes those who say the soul is blood by the
argument that the seed is not blood, and seed is the

22 elemental soul. Others, like Critias,^ regard the blood
as the soul, on the supposition that the most charac-
teristic attribute of the soul is sense-perception, and
sense-perception is due to the blood. So all the
elements, with the exception of earth, have received a
vote. No one has represented earth as the principle of
soul, unless it were certain philosophers who regarded
the soul as composed of all the elements, or as identical

23 with them all. They all define the soul, one may say,
in terms of three things : motion, sensation, and incor-

^ Alcmaeon, physician of Crotona, who is usually classified amongst
the Pythagoreans, regarded self-movement as the essential character-
istic of the soul. By means of this power of self- movement he appears
to have explained the continuity of organic life, in addition to finding
in it an argument for immortality. Vid. Siebeck, Oeschichte d. Psychol,
Th. I. Abth. i. p. 9L

''Critias, the leader of the Thirty Tyrants and uncle of Plato.

UK. I. vu. II. THKOHY OK ANAXA(;ORAS 17

poreality, and ciich of thoso Ih referred back to the
ultimate elements. Therefore, with one exception/ thoHc
who define the soul in terms of knowledge, make it an
element or a derivative of the elements. For they say
that we know like hy like, and inasmuch as it is the
soul that knows all thin<.;s, it must consist of all the 24
elements. Those philosophers'^ who maintain there is
only one cause and one element, rej^ard the soul as a
unit, like tire or air. On the other hand, the philo-
sophers who maintain that there are several elements,
make the soul a plurality. Anaxagoras alone declares
that the soul is affected by nothing and has nothing in
common with anything else. But, if this is its nature, 25
he did not explain, nor is it evident from his writings,
how the soul is to acquire knowledge and virtue. The
philosophers who include contraries amongst their first
principles ^ regard the soul as composed of contraries.
On the other hand, those who include in their principles
only particular contraries,* such as heat and cold or
similar opposites, likewise regard the soul as one of these.
And so there are some who take into consideration the 26
derivation of the words, certain of them claiming that
the soul is heat because the verb ' to live ' is derived from
this,^ others claiming the soul is cold, because the name
'soul' is derived from respiration and refrigeration. These,
then, are the traditional views of the soul, and these
are the grounds on which they have been advanced.

1 Anaxagoras. - The Ionian physiologers.

5 The Pythagoreans, who regarded the soul as a harmony of contraries.

■* Heraclitus, Empedocles, Hippo, and perhaps the pythagorizing
Alcmaeon.

^ I.e. because ^v (* to live ') is derived from ^eiu (' to seethe ') or ^vxv
{' soul ') from i^iJ^u (' refrigeration ').

B

CHAPTER III.

We must now proceed at once to the investigation of
motion. For the view ^ that the soul is a self-moving
406 fl entity, and capable of imparting motion, may not only
be a false theory of its essence, but it may even be an
impossibility for motion to inhere in it at all. We have
already said^ that what imparts motion is not of neces-

2 sity itself in motion. Everything that is moved is moved
in one of two ways : it is moved either by some other
thing or from a principle within itself. We speak of
objects moved by some other thing when they are moved
by being within a moving body, e.g. sailors. But sailors
are not moved in the same sense as that in which a ship
is moved. The one is moved in its own nature ; the
others are moved by being within a moving vessel.

3 This is clear when applied to the parts of the body ;
walking is a motion that is peculiar to the feet, but
it is also a property of man, though it is not a
property of sailors at the moment in question. Now,

^ Criticism of the view of Plato. The paraphrast Themistius cites
the Laws, Bk. 10, ed. Spengel. p. 26. Vid. Laws, 896, and Phaedr. 245,
246.

"^Phys. Bk. VII., Ch. iv. and v., 245 6-258 a.

18

BK. I. CH. III. TITK SOUL AND MOTION It

inasmuch an motion is ('m])loy(Ml in two senses, lot
iiH inv(^sti^'ato the soul, niid si.sk whether it is .self-
moved or only ])artieipate.s in movement. Movements
are of four kinds : movement in place, ([ualitative 4
cliange, decay, and growth. The soul's movement, then,
must be one, or several, or all of these. If it is not
moved accidentally, its motion must be a natural attri-
bute. If this is true, then space ^ must be an attribute,
for all of the aforesaid movements are spatial. If, then,
the essential nature of the soul is self-movement, its 5
movement will not be accidental, as in the case of the
movement of a white object or of an object three cubits
long. For what moves is body, of which these are only
predicates. Space, therefore, does not belong to them.
But space is an attribute of the soul, if the soul by its 6
own nature participates in motion. Again, if the soul is
moved by virtue of its own nature, it can also be moved
by external force. And if it can be moved by external
force, it can also be moved by virtue of its own nature.
The same conditions hold in regard to rest ; for in the
state into which an object is moved by nature, in this

^The arguments against the Platonic doctrines are, briefly summar-
ized, as follows: Motion cannot be the soul's essential nature, (1)
because this would require that the soul be spatial ; (2) the soul must
be moveable by external force ; (3) it must be held in rest by external
force, and these forced states of motion and rest are inconceivable ;
(4) the composition of the soul will be determined by the character of
its movements ; (5) it will experience the movements which it imparts,
and as it effects spatial motion, so it will experience spatial motion,
and may consequently enter into the body after having passed from it ;
(6) if movement is the displacement of the object in motion and the
soul's essential nature in movement, then motion would imply the soul's
displacement out of its essential nature. Vid. Wallace's excellent
note (Commentary ad loc), parts of which I have used in this con-
nection.

20 Aristotle's psychology deanima

state it also rests by nature. Likewise when an object
is moved by external force into a certain state, it also
rests in this state by force. It is not easy to give even
a conjectural explanation of the character of forced states
of motion and rest in the soul.

7 Again, if the soul's movement be upward, its composi-
tion will be fire, and if downwards it will be earth, for
these are the movements which are characteristic of these
elements. The same reasoning holds good of the inter-
mediate elements. Again, since the soul evidently sets
the body in motion, it is reasonable that it also experi-
ences those movements which it imparts. If this is true,
it is also true conversely that the motion which the body

406/' experiences is experienced by the soul. Now, the body

8 is moved in space. The soul should therefore change
place as the body does, and either the entire soul, or
certain of its parts, should change position. If this is
possible, then it would also be possible for the soul to
enter again into the body after it had once passed out.
From this would follow the impossible conclusion that
animals once dead can rise again. In regard to move-
ment in the sense of accident, the soul could be set
in movement by some external body, for an animal

9 might e.g. be pushed by external force. One must
not, however, suppose that a thing which in its essential
nature is self-moved, is moved by anything else save
in an accidental sense ; just as the absolute or
final good cannot be the relative or secondary good.
If the soul is moved at all, one would say that its

10 motion is caused by the objects of sense more than by
anything else. However, if the soul moves itself, it

ItK. I. (II. III.

rHI<: SOUL AND MOTION 21

must itself lixpcriuiico motion, so tliat on tho sui)positioii
that every niovuini^nt is th(5 (lisphicenKint of tli(5 o))joct
ill motion, in so I'm* as it is movcid, the soul muBt
sillier displacement out of its essential nature, provided
its self-motion is not merely accidental. Uut it is to
its essential nature that motion belongs. There are n
also some who, like Democritus, and in a spirit similar
to that of the comedian Philippus, say that the soul
moves the body^ (in which the soul resides), just as it
moves itself. For I'liilippus tells us that Daedalus
made his wooden statue of Aphrodite capable of move-
ment by pouring quicksilver into it. And Democritus 12
says much the same thing when he tells us that the
spherical atoms, which are never at rest, move the
whole body by their pull and push. But the question
we have to ask is whether these same particles produce
rest also. It is difficult or quite impossible to say how
they are to do this. In a word, it is not in this way that 13
the soul seems to set the body in motion, but rather by
some act of volition or thought.

Similarly the Timaeus ^ explains on natural principles
the soul's movement of the body : because it is self-
moved, it also moves the body with which it is
intimately bound up. The Timaeus regards the soul as 14
composed of the elements, and as divided into parts
corresponding to harmonic numbers, in order that it may
have an innate perception of harmony and possess in its
entirety harmonic movements. Timaeus thus bent the
straight line into a circle, which later he divided into
two circles joined at two points, and further subdivided

^ I.e. by mechanical action. - Timaeits, 34 A, 36 C.

22 Aristotle's psychology deanima

407 a the original circles into seven others, on the supposition

15 that the heavenly orbits correspond to the movements of
the soul. Against this view one may say, in the first
place, that it is incorrect to speak of the soul as a
magnitude ; by the soul of the universe he evidently
means some such thing as what we call reason. At any
rate it cannot, of course, be the sensitive or the appetitive

16 soul, for their motion is not circular.^ But reason is one
and continuous, as is also the process of thought. Now
the process of thought consists of thoughts, and these in
their succession form a numerical unity, though not a
unity in the sense of magnitude. Neither is reason,
therefore, continuous in this sense, but it is either
indivisible or not continuous in the sense of magnitude.
For how, indeed, is it to think, if it is magnitude ?
Does it think in its entirety or by means of some one of
its parts ? If it thinks by means of one of its parts,
it must be either as a magnitude or as a point, if

17 one can properly speak of a point being a part. Now,
if it be as a point and the points are infinite in number,
it is evident that it will never reach a conclusion ; if, on
the other hand, it be as a magnitude, it will think the
same thing many times or an infinite number of times.
But the fact seems to be that a thing is capable of being
thought once for all. If, however, it is enough that the
soul should have contact in any of its parts, why need it

^ The action of sensation and appetite is direct {i.e. they are, as Aris-
totle conceives them, directly from or to an object) and after the analogy
of a straight line. The action of reason, on the other hand, which
interprets things in terms of its own forms and laws, and in thinking
ideas returns, in a sense, upon itself, is analogous to circular movement.
The analogy is further evidenced by the continuity of its processes.
Cf. our expression to * revolve ' a thing in thought.

i.K. I. (11. 111. THK HOUL AND MOTION 23

move ill h circle or have any niai^iiitudc at all ? IJut if
thought nniuires contact in a complete circle, what is tlie
signiticanco of contact in any part ? A<^'ain, how is the i8
soul to think the divisible by means of the indivisible,
or that which has no parts by means of that which has
parts ? Reason, however, must be a circle of this sort.
For thought is the movement of reason just as revolution
is the movement of a circle. If, then, thought is a
revolving movement, reason must be a circle of which
thought is the revolving movement. And, more than 19
this, reason must always think something, if circular
motion is perpetual. Now, this cannot be true, for the
thoughts which issue in conduct have certain limitations
(they are all determined by an end), and speculative
thoughts are determined by logical processes. Every
logical process is either definition or demonstration.
Demonstrations proceed from a premise and have some 20 .
form of termination in a syllogism or conclusion. And
supposing they do not issue in a conclusion, still they do
not turn back to the premise or starting-point, but
continually take a new middle and extreme term, and so
proceed in a straight line, whereas circular motion turns
back to the starting-point. All definitions, too, are 21
determinate. Further, if rotation completes itself several
times, one will necessarily think the same thought several
times. Again, thought seems more like rest and
attention than like motion, and the same thing applies to
the syllogism. More than this, whatever is difi&cult or
contrary to nature cannot be pleasurable. Now, if motion
is not an essential property of the soul, the soul must move 407 b
contrary to its nature. And it must be painful for it to 22

24 Aristotle's psychology deanima

be united with the body from which it cannot free itself,
and such a union is even to be avoided, if it be true that
the reason is better off when separated from the body — a
view commonly held and concurred in by many persons.

23 The cause, also, of the circular movement of the
heavens is not clearly known. Circular movement is
certainly not due to the essential nature of the soul,
which moves in this way only accidentally, nor is it due
to the body, for the motion of the latter is due to the
soul. On the other hand, this motion is not ascribed to
the soul because of its being a better form of motion,
and yet it is just for this reason that God must have
endowed the soul with circular movement, firstly, because

24 motion is better than rest, and secondly, circular move-
ment is better than any other kind. Inasmuch as this
inquiry belongs more properly to other branches of
knowledge, let us dismiss it for the present. We may,
however, note one contradiction found in this and most
other theories of the soul. It consists in attaching the
soul to the body and placing it therein, without deter-
mining why this should be the case, and how the body is

25 related to the soul, although it would seem to be necessary
to know this. For it is by virtue of this union that the
one acts and the other is acted upon, that the one
receives and the other imparts motion — correlations
which are not found in things with merely accidental

26 associations. These theories simply attempt to explain
the nature of the soul, but add no explanation of the
body as its receptacle, because they suppose (in the spirit
of the Pythagorean myths ^) that any soul can clothe

^ More particularly in the myth of transmigration.

UK. I. «ii. Ml. I'KM-AUlS'rOTKI.IAN THKOIUKS 25

itself ill any body. TIiIh cannot be true, for every body
appears to Iiave a di.stinct form and cliaracter. 'I'heir
doctrine is very much like saying that the carpenter's *
art clothes itself in Ihitcs, whereas an art employs its
own instrument, just as a soul employs its own body.

^ Tho carpenter's art finds its pliysical and material cxprcasion in a
lu>usc but not in a tlutu ; further, it uses not a tlute, but an axe, as its
tool. A particular house is the expression of a particular art or of
particular ideas, just as a particular body is the expression of a definite
and individual soul. The soul is the entelechy and formative force of
tile body, and in it we look for the individuality and significance of the
man. It is precisely on the relationship between soul and body that
Aristotle lays especial stress in his definition of the former.

CHAPTEE IV.

There is another theory of the soul handed down from
our predecessors, which to the minds of many persons
is no less convincing than the theories already described.
Account has been taken of it even in our popular
treatises. This theory regards the soul as a sort of
harmony.^ Harmony, say its advocates, is a mixture
and combination of opposites. The body, too, is com-

2 posed of opposites. Although it is true that harmony
is a sort of relation in mixed parts or a combination
of parts, we maintain that it is impossible for the soul
to be either of these. Again, although motion is not an
attribute of harmony, yet almost all of the philosophers

408 a who hold the theory of harmony, I may say, ascribe
motion to the soul. Another objection is that it is
more fitting to apply the term harmony to conditions
of health or to bodily qualities in general than to the

3 soul. This becomes most evident when one attempts to
describe the effects and functions of the soul in terms

^ The reference is to the theory discussed in the Phaedo by the

guests of Socrates, — Simmias and Cebes, pupils of the Pythagorean

Philolaus. Vid. Phaedo, 86 A If.

26

UK. I. uii.iv. THK SOUL A HARMONY 27

of hariiioiiy ; for it is diflicult to find any corroHpondonce
betwocn thoin. Now, if we have two sorts (»!' liiinnony
in inind wIk^ii we use- this term, viz. harmony in the
primary sense, which means such composition of ma^^ni-
tudes in objects possessinj^' motion and position that
they fuse together and admit nothing further that is
homogeneous, and in the secondary sense, a ratio in
mixed elements, — we still object that in neither sense 4
does harmony apply to the soul. The composition of
the parts of the body can be readily examined. There
are manifold combinations of the parts, which may be
effected in many ways. Of what parts, then, is reason
a combination and how is the combination effected ?
And I raise the same question regarding the sensitive
and appetitive soul. It is equally absurd to regard 5
the soul as a ratio of mixture. The mixture of the
elements, in the formation of flesh and bone, is not in
the same ratio. If all the parts of the body are com-
posed of mixed elements, and the ratio of this mixture
constitutes harmony and soul, we have the absurd result
that we possess many souls distributed through the
entire body. One might demand from Empedocles an 6
answer to this question, for he says that every one of
these mixed elements is determined by a given ratio.^
Now the problem arises whether the soul is this ratio
or is something else begotten in the members. Again,
is Love the cause of any chance mixture or only of a
mixture in which a fixed ratio is observed ? And is
Love this ratio or something transcending the ratio
and different from it ? This theory, then, involves such 7

^ Cf. Burnet, Early Greek Philosophy, p. 227.

28 Aristotle's psychology deanima

difficulties as the foregoing. If the soul is different
from the mixture or combination, why in the world is
it that the soul is annihilated at the same moment as
the existence of the flesh and the other parts of the
living being ? Furthermore, if each part does not have
a soul, on the ground that the soul is not the ratio of
mLxture, what is it that is destroyed when the soul

8 leaves the body ? It is therefore clear from the fore-
going that one cannot regard the soul as a harmony
or its motion as circular. It is, however, possible for
it to be moved accidentally and to move itself, as e.g.
that in which it is may be moved, and this in turn
may be moved by the soul. But spatial movement is

9 otherwise impossible for the soul. One might with
better reason raise objections against the movement of

408 <J the soul, by regarding the following facts. We speak
of the soul as feeling pleasure, pain, courage, fear, and
anger, and as perceiving and thinking. Now all these
processes are apparently movements, and on this ground

10 one might suppose that the soul is moved. This, how-
ever, is not necessarily so. For even if the feeling of
pleasure or pain and the process of thinking be movements
in the highest sense of the term, and each of these be
a movement, it is possible that the movement is pro-
duced by the soul just as the feeling of anger or fear
is effected by a given movement of the heart and
thinking by a movement either of this or of some other
sort. Further, some of these movements are local, others
are processes of change, but of what particular sort or
how effected must be considered elsewhere. However,

11 to speak of the soul as feeling anger is like speaking

iiK.i. cii. IV. TlIK SOUL AND rHK UODV 29

of thn Houl lis woavin^^ or l)iiil(lint,' a house;. It is betUir
not to Hpe;ik of the soul as feelin<^ pity, or as learning
or thinkin<j;, hut nithcr of luiiu doin;^ thi.s through the
soul. We must not suppose, liowever, tliat this is so 12
because there is movement in the soul, but that move-
ment sometimes proceeds to the soul and sometimes from
it, as e.g. in sensation movement proceeds from outside
objects, in recollection the movement is from the soul
to excitations or fixed impressions lingering in the sense-
organs. Now, reason appears to be an entity which is
implanted in the soul and is incapable of being destroyed ;
for if it were perishable it would be destroyed by the 13
decay of old age more than by anything else. As a
matter of fact, the case is the same as that of the
sense-organs ; for if the old man could have the eye of
a young man he would see as well as the latter. Old
age, then, does not come because the soul has undergone
some change, but the change is in the soul's organ, the
body, as is the case in drunkenness and disease. 14

Thought and contemplation are, it is true, weakened
when some other internal organ is destroyed, but the
principle itself is unaffected. The processes of discursive
thought and the feeling of love or hate are not affections
of the reason,^ but of that which has reason in it, in so
far as it has it. Therefore, when this organism is
destroyed there is no longer either memory or love. For 15
these are not affections of the reason, but of that union
of soul and body which has perished. Eeason, on the
other hand, is something of a divine nature, and is

^ These processes are not affections of the eternal and separable Active
Reason, but only of the body in so far as it possesses psychical life.

30 ARISTOTLE S PSYCHOLOGY de anima

unaffected by these changes. From these facts, therefore,
it is clear that the soul is not in motion ; but if it is not
in motion at all, it is clear that it is not self-moved.

1 6 By far the most unreasonable of the above-mentioned
theories is the one which describes the soul as a self-
moving number,^ involving, as it does, impossibilities.
In the first place, it involves impossibilities regarding its
movement and especially regarding the notion of number.

409 a For how are we to conceive of a monad, a thing which is
without parts and without differences, as in motion, and
by what impulse and in what manner ? If it imparts
motion and is moved, it necessarily contains differences.

17 Again, since it is said that a line in motion generates a
plane and a point generates a line, then the movements
of monads will be lines, for a point is a monad which has
position. And the number of the soul is, of course,

18 somewhere, and has position. Again, if from a number
one subtracts a number or a unit, the remainder will be
a different number. But plants and many animals, when

19 cut in two, live and appear to retain the same specific
soul. It would also appear that there is no difference in
speaking of monads and of small bodies. For if the
atoms of Democritus are regarded as points, and quantity
alone remains, there will still be in this quantitative
element, as in everything continuous, a moving and a

^ The theory of Xenocrates. This theory is really a theory of
harmony. Xenocrates appears to have conceived of the elements of
the soul as commingled in such ratio as to produce a harmony (cf.
Themistius, ed. Spengel. p. 61). The real nature of this harmony is
due to the numerical ratio, and consequently the essential nature of the
soul is found in number. This is merely an application of the number
theory of the Pythagoreans to the explanation of the soul, to which,
however, Xenocrates adds the important notion of self-movement.

BK. I. en. IV. THE MONADIC TIIKOUY 31

moved factor. And tliis conseciuenco is duo not to any
dilVorcnco inside, l)ut merely to the fact that the elenienta
are (juantitative. There must, therefore, be something 20
which sets the monads in motion. r>ut if the soul is the
cause of animal movement, it will also be the cause of
movement in the nund)er ; the soul is therefore not at
once the moving and the moved principle, but the
moving principle alone. How then is it possible for the 21
soul to be moved ? There must be some difreronce
between it and other monads. But what difference can
there be in monadic points, excepting a difference in 22
position ? Therefore, even if the monads and points in
bodies differ from each other, the monads will, neverthe-
less, be in the same space as the points. For the monad
will occupy the space of a point. Now what is to
prevent an infinite number from occupying the same
space, if two can occupy the same space ? This supposi-
tion, however, is absurd ; for where the space occupied by
bodies is indivisible, the bodies themselves are indivisible. 23
But if the points in bodies are the number of the soul,
or if the soul is the number generated out of corporeal
points, why is it that not all bodies have a soul ? For,
presumably, there are points, — even an infinite number
of points, — in all bodies. Again, how is it possible
for souls to be separated and disintegrated from bodies,-^
if it be true that lines cannot be divided up into points.^

^ Xenocrates and the Platonists in general supported the doctrine of
immortality and the separability of the soul from the body. Aristotle
here attempts to disprove the number theory of the soul by showing its
incompatibility with the tenet of separability, and the consequent incon-
sistency of the Xenocratean philosophy with itself.

2 Points are not parts of lines, but only definite positions or boun-
daries.

CHAPTER V.

The peculiar absurdity of the number-theory consists, os
we said above, on the one hand in the fact that those who
advance it maintain the same position as the supporters
of the theory that the soul is a subtle body ; on the other
hand, in their explaining the movement of the body by
409^ means of the soul after the manner of Democritus. For
if there is a soul in every body capable of sensation,
there must be, on the supposition that the soul is body,
necessarily two bodies in the same space. Again, those
who maintain the numerical theory^ of the soul become
involved in the absurdity either that there are many
points in a single point, or that every body has a soul,
unless they make a distinction between physical and
2 psychical points. The consequence is that the animal is
moved by number, in the same way in which we said
Democritus explained its motion.^ For what is the
difference whether we speak of the movement of small

^ By interpreting the number-theory of Xenocrates as aelf-moving
monads, Aristotle reduces it to similarity with the atomic theory of
Democritus, and applies the criticisms of the latter to the former.

'^The animal is moved by psychical monads, just as in the theory of
Democritus it is moved by psychical atoms (cf. De an. 4066 20).

32

UK. I. CM. V. TIIK SOUL AND THK KI.KMKNTS 33

spherical hodii's or of hiri^c iik^hikIs or of moiiads ;il
all ? Kor in uitlier c.aHO thc^ Jiniiiial iiiovernont inu.st
bt' due to tiu' motion of the monads. Tlio above i
objections and many similar ones may be raised against
the third ^ chiss of philoso])hers who combine motion and
number in their theory. This is not merely an impossil)!e
dc^tinition of the soul ; it is even an impossible attribut(\
This becomes evident if one tries to explain in terms of 4
this motion^ the feelings and functions of the soul, such
as deductions, sense-perceptions, pleasure and pain, and
similar processes. It is not easy, as we said above,^ in
terms of such a theory, to form even a conjecture of the
nature of these functions. Of the three'* traditional 5
explanations of the soul, there is one which describes the
soul as the most mobile element because of its self-
movement ; there is another which describes it as the
most subtle or incorporeal element. The difficulties and
contradictions involved in these two have been pretty
fully explained. There remains for us the consideration
of the theory of its composition from the elements. The 6
soul is composed of the elements, certain philosophers
say, in order that it may perceive and know all reality.
But there are many difficulties which make this theory
impossible. Its advocates assume that like is known by

^ Xenocrates and the pythagorizing Platonists.

- In terms of number. -^ De an. 4086 32.

^The explanations apparently referred to are : (1) that which regards
the soul as a self-moving number (Xenocrates) ; (2) that which regards
it as composed of the finest and most mobile atoms (Democritus), or of
the subtlest substance (Anaxagoras), or perhaps as consisting of Har-
mony (Plato) ; (3) that which regards it as composed of the elements.
This third class of theories lays chief weight on the soul as an instru-
ment of cognition.

C

4ioa

34 Aristotle's psychology deanima

like, thus making the soul and its object in a sense
identical. But the soul knows not merely these elements ;
it knows a great number, one would better say an infinite
7 number, of other things, derivatives of the elements. Let
it be granted that the soul knows and perceives the
elements in every real thing ; by what means is it to
know or perceive the concrete object, e.ff. what is God, or
man, or flesh, or bone, or any other similar composite
thing ? For the elements are not combined in any
haphazard way to form things, but in a fixed ratio
and composition, as Empedocles himself says in regard
to bone ■}

" Earth, the lovely, in her smelting pots, broad moulded,
Obtained from sparkling Nestis^ two parts of the eight ;
Four from Vulcan's fire : so were white bones begotten."

There is, therefore, no advantage in having the ele-
ments in the soul unless the ratios and combinations are
also to be found in it. Each element will know its
similar counterpart, but it will not know bone or man
unless these also are to be found in it. One need
scarcely say that this is impossible. For who could be
in doubt whether a stone or man were to be found in the
soul ? The same holds true of the good ^ and the not-
good, and equally of other instances. Again, inasmuch as
the term * Being ' is employed in several meanings (it

^ Vid. Burnet, Early Greek Philoj^ophy, p. 227 ; Ritter and Preller,
Hist. Philos. GVaec, 8th ed., p. 14.3.

2 Water.

^To Aristotle the good is not an entity or element, and so is not
explicable by the theory of Empedocles. The good is a relation, and
consists in being a mean between two extremes, both of which (excess
and defect) are evil.

9

UK. i.<ir. V. riri': soul and rifK iimvMkxts 3B

(loimU's r.<i. i\n\ iudividiiiil corK^rete tiling', or <iuaiitity, or
(luality, or sonic, other particul.'ir caU'j^'ory), the <jii(\stion
arises whnthcr the soul is composed of all th(!se cate-
gories. Il is siij)))oscd that there are no elements which
are common to all the cate«4ories. Is the soul, tlien, lo
composed only of the elements which fall under the
category of substance '( If so, how docs it cognize the
other elements ? Are we to say that there are elements
and specific principles which belong to every category of
existence, and that the soul is composed of these ( The
soul will then be a quantity, a quality, and a substance.
Now, it is impossible to form a substance or anything
but a quantity out of elements of (juantity. These and
similar objections may be urged against the theory that u
the soul is composed of all the elements. Again, it is
absurd to say that like is unaffected by like, and yet
maintain that like perceives like, and that we know like
by like. At the same time these writers regard per-
ception, as well as tliinking and knowing, as a sort of 12
affection and movement. The theory, as Empedocles^

^ Empedocles starts with the psychological principle that like is
known by like. Consequently, if objective reality, which consists of
the four elements (fire, earth, air, and water,) is to be known, then the
knowing soul must be composed of the like elements. Aristotle's
objections are as follows : (1) The soul not only knows the elements, but
a great many other things, for which the Empedoclean theory that
' like is known by like ' makes no provision. (2) It is of no value that
the soul consist of the elements, unless in some way it be made to con-
sist of the ratios and combinations of these elements. How, e.r;., can
man or stone be known, for no one supposes that either of these is in
the soul ? (3) In what category is the soul to be classed ? It cannot be
regarded as all of them, for the different categories have no common
elements, and if it is referred to one or the other of the ten categories,
it will know only the objects that belong to this category, while it will
be ignorant of the others. (4) Empedocles is further in the dilemma of

36 Aristotle's psychology de anima

states it, that things are severally cognized by means of
somatic elements and that like elements are cognized by
like, is open to many objections and difficulties, as is
proven by what we have just said. For it is plain that
such elements in animal bodies as are composed merely of
410^ gross matter, like bones, sinews, and hair, do not perceive
anything, not even objects like themselves. According to

13 the theory, however, they ought to perceive the like.
Further, more ignorance than knowledge will attach to
every element ; for it will know only one particular
thing, while it will be ignorant of much, for its ignorance
will extend to everything else. And Empedocles is in
the dilemma of making God the most unintelligent of
beings ; for he alone is ignorant of one of the elements,
viz., Strife, while mortals know them all, because they

14 are formed from them all. There is, further, this general
question to be raised : Why is it that all entities do not
possess a soul, since everything is either an element or a
derivative of one or several or all of the elements, and

15 must, therefore, know one thing or certain things or all
things ? One might raise the further query : What is it
that unifies these elements into objects ? The elements
are like a corporeal substrate, while it is the unifying
principle, whatever that may be, that is the main thing.
But there can be no superior principle to dominate the
soul. This impossibility applies most of all to reason.
For reason is, with good cause, called nature's first-born

making God the most ignorant of beings, because one (vid. Ueberweg-
Heinze, 8th ed., Th. i., p. 83) of the elemental cosmical principles —
* Strife ' — is excluded from his nature. (5) Again, why does not every
element or combination of elements possess a soul ? (6) The theory of
Empedocles provides no unifying principle.

rK. I. (Ml. V. rilM SOUL ANI> I III': i:LKMKNr.S '^^

ruler, iilthouj^h tlu^sc, |)hil()S(»j)herH roi^ard th(3 ♦iluments as
tlio })riinjiry rt'{iliti(;H. All tlu; pliilosopliors who iniiinLaiu i6
the doctrine thiit the houI is competed of the elements
hecause it knows and perceives realities, and those who
deacrihe it as the most mobile entity, fall into the error
of not referring to the soul in its entirety. For not
every sentient creature is capable of movtMuent.^ Certain
animals are observed to be stationary in place. And yet
this seems to be the only form of movement that could
be meant when one says ' the soul moves the animal.'
A similar objection may also be urged against those who 17
describe the soul and the sentient principle as composed
of the elements, viz., that plants evidently live without
participation in movement or sensation, while many
animals are not endowed with thought. But even if
one were to make a concession and regard reason as a
part of the soul, in a sense similar to that in which the
perceptive faculties are parts of the soul, still even then
one would not be taking every form of soul into con-
sideration, nor the whole of any particular soul. And
this is just what happens in the account of the soul given 18
us in the Orphic verses, as we call them.^ For there we
are told that the soul enters from the universe into
individuals as they breathe, and that it is carried by the
air. But this is impossible in the case of plants and
also in the case of certain animals; because not all of 411 «
them breathe — a fact which the supporters of this view 19

^ This objection appears to apply not to Empedocles, but to Demo-
critus and Xenocrates. Motion cannot belong to the essential nature of
soul, for certain sentient creatures are stable and incapable of motion.

^Aristotle evidently considered the Orphic origin of these early
Cosmogonies as a doubtful tradition.

38 ARISTOTLE S PSYCHOLOfJY de amma

have overlooked. Even if we admit that the soul must
be composed of the elements, it is not necessary that it
be composed of all of them ; for either member of two
contraries is competent to discern both itself and its

20 opposite. For example, by the concept of the straight
we discern both the straight and the crooked ; the rule is
the test for both, while the crooked is not a test either of
itself or of the straight.

Certain philosophers^ maintain that the soul is diffused
throughout the universe, which may account for Thales''^
thinking that all things are full of gods. This view is also

21 attended by certain difficulties. Why is it that the soul
which is in the air or in the fire does not generate an
animal, while such generation takes place in compound
bodies, although they regard that which is contained in
the former elements as superior to that which is con-
tained in compound bodies. One might also ask the
question : Why is it that the soul contained in the air is
better and more imperishable than that which is found
in the animal body ? There is a two-fold objection to

22 this theory : it involves an inconsistency and a paralogism.
To speak of fire or air as animal is paralogistic ; while
not to call them animal, if they have a soul, is incon-
sistent. They appear to think there is soul in these

23 elements on the ground that the whole is homogeneous
with its parts. The result is, they must say that the

^ The reference here may be to the theories advanced in the Timaejis
(SOB, 34 B; cf. Bartheleniy-St.-Hilaire, Psychol. (rArisfofc, p. 155,
and Themistius Comment, ad /or.), or to the theories of Heraclitus
or Empedocles or Diogenes of ApoUonia. The theory of paupsychism
is best represented by the post- Aristotelian Stoics.

- Vifl. Burnet, Early Orcp.k PhUoso-phy, p. 42.

MK. I. en. V. TUM SOUI. AND ITS PARTS 39

soul is li()in()«^'(Mi(M)Us witli its i>!irts, ij' it he truo tbdt
jiuiiuals bocoino (UkIowimI with soul l»y tjikiii;^ into thorn-
solves S()niothin<4' from their onvironiuont. If, however,
th(i (lill'used air is honio<»eneous, luid the soul consists of
heterogeneous parts, it is evident that some of its parts
and not others will be contained in the air. The 24
consequence is that the soul must either consist of like
parts or not be found in every elenuMit of thc^ uni-
verse.

From the aforesaid it is evident that knowledge does
not belong to the soul in virtue of its composition out of
the elements, neither is it right or true to say that it
is moved. But inasmuch as cognition, sense-perception, 25
and opinion, as well as appetite, volition, and desire in
general are functions of the soul, and inasmuch as
locomotion in animals is effected by the soul, and it is
also by virtue of the soul that animals grow, reach their
prime, and decay, the question arises whether each of these
functions is to be ascribed to the entire soul. In other 411.^
words, is it by means of the entire soul that we think,
perceive, and are moved, and perform and undergo every
other process, or do we perform each different function by
means of a different part ? Again, we may ask whether 26
the principle of life is found in each one of these parts
or in several or in all of them. Or is something other
than the soul ^ the cause of life ? It is true that some
writers maintain the divisibility of the soul and that one
part exercises thought and another part exercises desire.

^ According to Aristotle, life is one of the psychical functions,
although the most elementary of all of them, and is a prerequisite to
all other forms of psychical activity.

40 Aristotle's psychology deanima

27 If the soul is really divided in its nature, what is it that
holds it together ? It is certainly not the body ; for, on
the contrary, one supposes that the soul holds the body
together. At any rate, when the soul departs the body
is dissolved and disintegrated. If, therefore, it is some-
thing other than the body that makes the soul an unit
this would assuredly be the soul itself, and we shall
be obliged to inquire again whether that unifying
principle is itself an unit or is composed of several parts.

28 If it is an unit, why should we not say at once that the
soul is an unit ? But if it is divisible, reason will again
ask what that principle is which holds it together, and so
the process will go on ad infinitum. In regard to the
parts of the soul, one might inquire concerning the power

29 which each of them has in the body. For if it is the
soul as a whole that binds the entire body together, it
would be fair to suppose that each part of the soul is the
binding principle for some part of the body. This, how-
ever, appears to be impossible. It is hard even to fancy
what sort of part the reason will bind or in what way.

30 It is observed also that plants and certain insects, when
divided, continue to live, because the sections possess
souls, which are specifically, although not numerically,
the same. Each part retains the power of sensation
and locomotion for some time, and there is nothing
strange in the fact that it does not continue to live,

31 because it has no organ for the maintenance of its nature.
Nevertheless the parts of the soul are all found in every
one of these bodily divisions, and they are of like kind
with each other and with the entire soul ; of like kind
with each other because they are mutually inseparable;

MK. I. (II. V. DiN'Fsinn.riN OK rm-: soul 41

<•!' likt; kind with thu I'lilirr soul hccjiu.sc; it in divided
into theao as })iirts. Aj^'ain, the fuixlamental principle ol
life in plants appears to be a kind of soul, and this is tin-
only principle which animals and plants have in coninion.
The principle of life can exist ajiart from sensation, but
no sentient thinj> can exist without life.

BOOK THE SECOND.

CHAPTEE I.

^i2a Let the foregoing suffice as a discussion of the traditional
theories of the soul ; and now let us resume our subject
from the start, and attempt to determine the nature of
2 the soul and its most general definition. One class of
realities we call 'substance.' This 'substance' may be re-
garded on the one hand as matter, which in itself is no
definite thing ; on the other hand, as form and idea, in
terms of which definite individuality is ascribed to a
thing. A third meaning of substance is the composite
of matter and form. Matter is potentiality ; form is
actuality or realization.^ The latter may be looked at

^ The notions here under discussion belong to the most fundamental
with which the philosophy of Aristotle operates. The soul is character-
ized by several terms, chief of which are form and entelechy. Every
individual or ' substantial ' thing is a composite of form and matter.
Form is that which gives a thing its character or significance. It is
form, therefore, that is the object of knowledge. Becoming consists in
the process of matter assuming a definite form. Matter, consequently,
represents the potentiality of a thing, and form its actuality. Viewed
from the standpoint of causation or process, these two notions constitute
the material and formal causes ; in other words, matter is the condition
nine qua non, while the form is conceptual, efficient, and final cause.

42

UK. II. < II. I.

TUK NOTION OF * SIJHSTANCK ' 43

in two ways, either as complete realization, — coinimrable
witli ])erfect(Ml knowlc^df^'c, or a.s realization in j)nK'.eH.s, —
comparable with tlu; activity of contemplation. The 3
notion of suh.stance appears to be most generally employed
in the sense of body, and particnlarly of physical body ;
for this is the sonrce of all other bodies. Some physical
bodies have, and others have not, life. Wy life we nnder-
stand an inherent principle of nutrition, growth, and
decay. So that every natural body endowed with life
would be substance, and substance in this composite sense. 4
The body, therefore, would not be soul, since body is of

These fundamental terms in Aristotle's metapliysics are applied by him
to the e,\pIanation of the soul. Man is first of all an organic whole, the
living force in which is the soul, while the body is the soul's organ.
Soul is that which dilferentiates a living from an inanimate thing,
{De an. 418a 33), and life signifies a process or a form of motion. Life
implies, further, an active and a passive element; in other words, a
moving principle and a thing moved, which in Aristotle's terminology
are form and matter. Form here is equivalent to the moving or
efficient cause. It is the energy or life that determines the g'-owth of a
particular body, or its transition, in Aristotelian language, from
potentiality to actuality. Every living thing, then, is a composite of
form and matter, or soul and body. In so far as the form is the
perfected end or final cause, in so far Aristotle describes the soul as the
entelechy of a natural organic body. In so far as it is an efficient power
or moving cause, he describes the soul as the actuality or actualization
(an inadequate translation of evipyeia). It is only in the "soul that
body attains its true reality " (Wallace, Introd. p. xxxix.). Soul is the
realization of the body, apart from which the body is only formless,
undeveloped, potential matter. Entelechy (eVreXe'xeia) means the
finished state of a thing [Phys. 202a 24) or a state in which a thing's
potentiality finds its complete development. Actualization {evepyeia),
on the other hand, means the active process by which the potential
thing passes over into the completed state or it is the completed
state in process. Entelechy is, therefore, more ultimate than
actualization (ivepyeia), although Aristotle frequently vises the terms
synonymously. On the term efipyeta, rid. Grant's AristotWs Ethic'i,
Vol. I., pp. 231 ff. 4th ed., and Trendelenburg's Aristotle' i^ De anima,
2nded., pp. 242 ff.

44 Aristotle's psychology deanima

such nature that life is an attribute of it. For body is
not predicated of something else, but is rather itself sub-
strate and matter. The soul must, then, be substance^
in this sense : it is the form of a natural body j
endowed with the capacity of life. In this meaning

5 substance is the completed realization. Soul, therefore,
will be the completed realization of a body such as
described. Complete realization is employed in two
senses.^ In the one sense it is comparable with per-
fected knowledge ; in another, it is comparable with the
active process of contemplation. It is evident that we
mean by it here that realization which corresponds to
perfected knowledge. Now, both waking and sleeping
are included in the soul's existence : waking corresponds
to active contemplation ; sleep to attained and inactive
knowledge. In a given case science is earlier in origin^

6 than observation. Soul, then, is the firsf* entelechv

' Substance is employed by Aristotle in three senses : (l) matter ; (2)
form ; (3) the composite of matter and form or an individual thing. Cf.
Zeller's Aristotle^ Engl. tr. Vol. I. pp. 374 fif. ; Grote's Aristofle, p. 454.

- These two senses are described by Aristotle in the terms entelechy
and actualization {ivepyeia), the former of which corresponds to ' per-
fected knowledge ' and the latter to the process or activity of ' contem-
plation.'

^ In the sense of being a dormant possession, or a potentiality which
subsequent activity presupposes.

^The 'iSrst' entelechy is variously explained by the diflferent com-
nientators from Simplicius down. The notion of ' first ' appears to refer
to the distinction made in the previous Note. There is a primary and
secondary substance {ovala), the former of which refers to tlie individual,
and the latter to the genera ; there is a primary matter (Trpwrrj v\r},
Metaph. 1049ft 2.")), which signifies matter absolutely formless; there is,
further, a primary soul (wpibTt} •^vxVt ^' nn. 4166 22), which is the
most fundamental or primary form of soul, viz., the nutritive function ;
and similarly there is a first entelechy {irpwrr] fVreX^xf'ct)? which is the
])rimary or most fundamentnl form of psychical life. It is primary or

I, K. II. (II. I. DI-IKINITION (H<' rHK SOUL i^t

of Ji natural body ciidowrd with (Ik; capacily of lifn.
Such a, IxmIv one would doscrilx* as or}.;ai»i( . 'I'lu* parts
of plants arc also orL,Muis, allhouj^di (jiiito simple in char- a^2/>
acter, r.t/. tlu' l(>af is the covering' of the pericarp, and
the pericarp is coverin;^ of LIk' I'ruit; tln^ roots are
analogous to mouths, both bein^' channels of nutrition. 7
If then we were obliged to give a general description
a]iplicable to all soul or life, we should say that it is the
tirst entelechy of a natural organic body. It is therefore
unnecessary to ask whether body and soul are one, as one
should not ask whether the wax and the figure are one,
or, in general, whether the matter of a particular thing
and the thing composed of it are one. For although
unity and being are predicated in several senses, their
proper sense is that of perfect realization. (0)^v»*>«jj.at.^)

We have now given a general definition of the soul, s
We have defined it as an entity which realizes an idea.
It is the essential notion which we ascribe to a body^/^
of a given kind. As an illustration, suppose that an
instrument, e.g. an axe, were a natural body. Here the
notion of axe constitutes its essential nature or reality,
and this would be its soul. Were this taken away it
would no longer be an axe, except in the sense of a
homonym. It is in reality, however, merely an axe, 9
and of a body of this sort soul is not the notional

first in the sense of being nearest to mere potentiality, and in the order
of development stands next above body. It is also tirst in being a pre-
requisite to all further development. The 'first entelechy of a body' is,
consequently, the first manifestation of life which an organism displays.
It corresponds to dormant knowledge or merely possessed science,
which is potentiality {dvvafiLs, e|is) compared with the active employ-
ment of science (evf/yyeia), and as potentiality, it is prior to the latter.
(Cf. Zeller's Aristotle, Engl. tr. Vol. II. p. 3, note 1.)

46 Aristotle's psychology deanima

essence and the idea, but soul applies only to a natural
body of a given kind, viz. a body whose principle of
movement and rest is in itself.^ The principle expressed
here should be observed in its application to par-
ticular parts of the body. For if the eye were an

10 animal, vision would be its soul, i.e. vision is the notional
essence of the eye. The eye, however, is the matter of
vision, and if the vision be wanting the eye is no longer
an eye, save in the meaning of a homonym, as a stone
eye or a painted eye. What applies here to a particular
member, must also apply to the entire living body ; for
as the particular sensation is related to the particular
organ of sense, so is the whole of sensation related to
the entire sensitive organism, in so far as it has sensa-

1 1 tion. ' Potentiality of life ' does not refer to a thing
which has become dispossessed of soul, but to that which
possesses it. Seed and fruit are potentially living bodies.
As cutting is the realization of the axe, and vision is
the realization of the eye, so is the waking state the
realization of the living body; and as vision and capacity

413 a are related to the organ, so is the soul related to the
body. Body is the potential substrate. But as vision
and pupil on the one hand constitute the eye, so soul
and body in the other case constitute the living animal.

12 It is, therefore, clear that the soul is not separable from
the body ; and the same holds good of particular parts
of the soul, if its nature admits of division, for in some
cases the soul is the realization of these very parts ;

^ The meaning is that if an axe were a body with an inherent principle
of movement, or in other words an animate body, then the notion of
axe or axehood would constitute its soul. The soul, then, is the
• notional essence,' to use an Aristotelian phrase, of a living body.

UK. II. .11. I. DKKINITION Ol' THK SOUL 47

not hiiL thai {\\viv. arc ccrtiiiii other parts whiT*^ nothiii)^
forbids thciir ])()ssible Hcparation, because they are not
realizations of any bodily nature.' And yet it is un-
certain whetber the soul as realization of the body iH
separable from it in a sense analogous to the separability
of sailor" and boat. Let this suflice as a definition and
outline sketch of the soul.

' The reference is to the Active Reason.

~As the sailor is the directing and animating principle, as it were,
of a boat and is able to leave it at will.

CHAPTER 11.

Inasmuch as the certain and the conceptually more
knowable is derived from what is uncertain/ but sensibly
more apparent, we must resume the investigation of the
soul from this standpoint. For it is necessary that the
definition show not merely what a thing is, as most
definitions do, but it must also contain and exhibit the

2 cause of its being what it is. In reality, the terms of
definitions are ordinarily stated in the form of con-
clusions. What, e/j. is the definition of squaring ? The
reply is that squaring is the conversion of a figure of
unequal sides into a right-angled equilateral figure equal
to the former. Such a definition is the expression of
a conclusion. But to define squaring as the discovery

3 of a mean proportional line is to define the thing in

^The only certain and scientific knowledge to Aristotle is that of
concepts or universals, although this is in a way derived from sensible
data. Aristotle is not, liowever, a pure Empiricist. Sense-per-
ception itself is not a passive reception of external impressions ;
these furnish rather only the occasion of a given psychical activity,
and rational thought is in still higher degree a matter of subjectivf
initiation. He rejects, however, the Platonic theory of reminiscence
and all other theories which assume the possession of a body of innate

truths.

48

jiK. II. (MI. II. ANTMATK AND INANIMATK 49

terms ol' its cuii.so.' lieHUiniii)^ our iii([uiry, wc; Hsiy,
therelbre, that the jininuiU^ is (li.stin«,MiiHhed from the
inanimate by the principle of life. lUit inasmuch as life
is predicated in several senses, <.//. in the sense of reason,
sensation, local movenicnl and rest, and furthermore
movement in the sense of nutrition, decay, and growth;" 4

'The ono definition iloscribea the result accomplished, and the other
the means and method of its Hco()m[)lishment. Altiiough Aristotle lias
great veneration for facts, to a degree remarkable in Greek philosophy,
he constantly lays emphasis on the superior significance of relations
and causes.

^Aristotle's view of soul or the 'vital principle' (neither translation
gives quite an adequate idea of the meaning of i'vxht of. Introduction,
Chap. i. ) is difi'erent from that of Stahl and the Montpellier School of
Animists. The latter regard the mind as the source of all vital phe-
nomena, whereas Aristotle regards life as the source of mind, or rather,
mind as only one of several forms of life. The distinction between the
two views is made greater by Lewes {Aristotle, p. 223) than the facts
justify, he having, as he supposes, made the discovery of this
distinction. In reality Aristotle characterizes life as a psychical
activity, though not necessarily intelligent. The organic activity in
plants is psychical, although they have no sensation. Aristotle used
life in a wider meaning than we do ; with him it included reason
and sensation, as amongst the vital activities of organized beings.
These combined activities constituted ' soul ' in distinction from the
material substrate or body, in which they are manifested. Stahl
(1660-1734), whose theory of the soul grew out of his physiological
studies and was a reaction against mechanical and chemical theories,
rejects the Aristotelian distinction of a vegetative and nutritive soul,
and refers all these functions to rational thought. The three forms of
vital movement for Stahl are the circulation of the blood, secretion, and
excretion, all of which Aristotle includes amongst the activities of
nutrition, save that the circulation of the blood takes the form of
movement from the heart to the extremities and back again. Stahl says
the cause of this is the mind ; Aristotle says it is the nutritive soul or
the lowest form of vital activity. Both are vitalists in the repudiation
of a mechanical explanation of life ; both are animists in referring the
phenomena of life to the soul. They differ in that Stahl makes all
these activities rational, while Aristotle regards as rational only specific
activities in higher animal life. Cf. Lemoiue, Le vitalisme et Vanimisme
de Stahl, pp. 33 ff.

D

50 ARISTOTLE S PSYCHOLOGY de anima

if any one of these is discerned in a thing we say that
it has life. All plants, therefore, are supposed to have
life ; for evidently they have within them a potency
and principle whereby they experience growth and decay
in opposite processes. For their growth is not merely
upwards or downwards, but in both these directions
alike and in every point where nutrition takes place,
and they continue to live as long as they are capable of

5 nutrition. Now this faculty of nutrition is separable
from the other forms of life, but the other forms cannot
exist in perishable creatures apart from this principle
of nutrition. This is made clear in the instance of
plants ; for they have no other capacity of soul (or life)

413 <j than this nutritive one. Owing to this fundamental

6 principle of nourishment, therefore, life is found in all
animated living things, but the primary mark which
distinguishes an animal from other forms of life is the
possession of sensation. For even those creatures which
are incapable of locomotion or change of place, but
which possess sensation, are called animals and are
not merely said to live. Touch is the primary form

7 of sensation and is found in all animals. But as the
nutritive faculty is separable from touch and sensation
in general, so touch can exist apart from the other forms
of sensation. By the nutritive power we understand
that part of the soul in which plants share ; and by
the sensation of touch we mean that capacity which
all animals possess. We shall later on give the ex-
planation of these phenomena.

S For the present let it suffice that the soul is the
causal principle of the aforesaid phenomena, and is

HK. II. CM. II. T\\\'] IMUN(:iI»LK OF LIKK r>|

defined in terniR of iIkmii, 1 muun, in torniH of nutrition,
aenaation, reason, motion. To tlie (|ue.stion whether each
of these forma of WW is a sonl or a ])art of the soul ;
and, if a })art, wlicthcr in the sense that the part is
oidy notionally separal>le or really separable in space, —
the reply is in some respects easy and in others
difficult. For in the case of plants, some of them appear 9
to live when they are divided up and the parts are
separated from each other, indicating that there is in
each of these plants in actuality an unitary soul, but in
potentiality several souls. And we observe the same
thing taking place in different varieties of soul, as e.(/. in
the case of insects which have been dismembered. Here
each part is capable of sensation and locomotion, but if it
is capable of sensation it is also capable of imagination
and impulse. For where there is sensation, there is also
pleasure and pain, and where there is pleasure and pain
there is necessarily also desire. Now in regard to reason id
and the speculative faculty, we have as yet no certain \ y^
evidence, but it seems to be a generically distinct type of
soul and it alone is capable of existing in a state of,
separation from the body, as the eternal is separable from
the mortal.^ The remaining parts of the soul, however, n
are from the foregoing considerations evidently not
separable, as some assert.'^ But that they are notionally

^Amongst the uncertain and wavering statements of Aristotle
regarding the separability of the rational soul and its immortality, this
b one of the most explicit passages.

2 The reference appears to be to Plato who regarded the soul as con-
sisting of three distinct faculties, — the rational, spirited, and appetitive
{Bepub. 440 a, b, Timaexis^ 69, 70), which were situated in different
parts of the body, — reason in the head, the spirited element in the
thorax, and the concupiscent faculties in the lower body.

X

52 Aristotle's psychology deanima

separable, is clear; for if perceiving is distinct from
opining, the faculty of sensation or perception is dis-
tinct from that whereby we opine, and each of these is
in turn distinct from the faculties above mentioned.

12 Furthermore, all of these are found in some animals,
while only certain of them are found in others, and in
still others only a single one (and this is the cause of dis-

414 a tinctions amongst animals). The reason for this must be
investigated hereafter. A parallel instance is found in
regard to sensation ; some animals possess all the faculties
of sense, others only certain of them, and still others only
the single most fundamental one, viz. touch.

13 The principle by which we live and have sensation,
then, is employed in a twofold sense. Similarly, we
employ the principle by which we know in a twofold
sense, viz. science and the knowing mind (for we say we
know by means of each of these), and in a like manner
the principle by virtue of which we are healthy is in one

14 sense health itself, and in another sense a part of the
body or the whole of it. In these cases knowledge and
health constitute the form, notion, idea, and, as it were,
the realization of a potential subject, — the one of a
knowing subject and the other of a healthy one,
(realization is supposed to attach to that which has
power to effect changes and is found in a passive and
recipient subject). The soul is that principle by which
in an ultimate sense we live and feel and think ; so that
it is a sort of idea and form, not matter and substrate.

15 Now, substance is employed, as we have said, in a three-
fold meaning, viz. as form, as matter, and as a composite
of these two. Amongst these meanings of substance

HK. II. (11 II. rm<: soul and body 53

matter Hi«^Miitie8 potentiality ; roiiii Ki«,niilies actuality or
complete realization. Inasmuch as it is the composite
which is the animate creature, hody cannot Ix; ni^'ardod
as the complete; realization of the soul, but the soul is the
realization of a given body. The conjecture, therefore, i6
appears well founded that the soul does not exist apart
from a body nor is it a particular body. The soul is not
itself body, but it is a certain aspect of body, and is
consequently found in a body, and furthermore in a body
of such and such a kind. It is not to be regarded as it
was amongst our predecessors who thought that it is
introduced into body without prior determination of the
particular sort of body, although no casual subject
appears capable of undergoing any casual or haphazard 17
eff'ect.^ This same result is also reached by an analysis
of the notion itself; for complete realization in every
instance is naturally found in a definite potentiality and in
an appropriate matter. From this it is evident that the
soul is a kind of realization and expressed idea of a
determinate potentiality.

* Trendelenburg thinks the Pythagoreans are meant here, owing to
their doctrine of transmigration of souls. The doctrine that one soul
can clothe itself in dijBferent sorts of bodies is as impossible as that one
craft can use the tools of other crafts indifferently. Cf. De an. 4076 22;
vid. also note, p. 25.

CHAPTER III.

In some creatures, as we have said, all of the above
mentioned psychic powers are found, in others certain of
them, and in still others only one. By powers we mean
here the power of nutrition, of appetite, of sensation,
of movement in space, and of rational thought. In
plants, only the nutritive power is found ; in other
414* creatures the power of sensation is added. If sensation

2 is added, impulse or appetite is also implied. For
appetite includes desire and impulse and wish. All
animals have at least one sense — touch ; and to whatever
creature sensation is given, to it are also given pleasure
and pain, and objects appear to be pleasant or painful.
Creatures which distinguish these, possess also desire ; for
desire is an impulse towards what is pleasant. Further,

3 animals possess a sense for food, and this is the
sense of touch ; for all animals are nourished by means
of the dry and moist, the warm and cold, and it is
touch which apprehends these. It is only incidentally
that animals discern food through other sensible
qualities ; neither sound nor colour nor smell con-
tributes at all to food. Flavour, however, is one of the

54

i«K. II. (Ml. III. VARIOUS MKANINCS OF SOUL TjS

haptic qualities.' Ilun;^'er and ihirHt are deHires ; hunj^'cr 4
is a desire of the dry and warm ; thirst a dcsin! of
the cool and moist, ami Uavour is a sort of seasoning
in these objects. We must explain tiiese Hubjects
minutely hereafter ; for the present let the statement
suffice, that amon^^st animals where we find touch
we find appetite also. The subject of imaj^ination
in animals is uncertain and must be investigated later.
In addition to these attributes we find amongst some 5
animals the power of local movement and in others we
find the power of understanding and reason, as in man
and in other creatures that are, if there be such, similar or
superior to man. It is evident that a single definition
can be applied to soul in the same way as a single
definition can be applied to figure. As in the latter case,
there is no figure beyond that of the triangle and its
derivations, so in the former case there is no soul beyond
those enumerated. A common definition might also be 6
applied to figures which would fit them all and be
peculiar to no particular figure. The same holds good in
the case of the above mentioned types of soul. It is,
therefore, absurd,^ both in these instances and in others, to
search for a common definition which shall not apply to
any individual real thing nor to any peculiar and irre- 7

^ Touch is the most fundamental of all the senses, and taste is depen-
dent upon it. These two are essential to the preservation of animal life.
No animal can be without touch and nothing that is without it can be an
animal. As the primary form of sensation, it is the lowest differential
mark of animal life, distinguishing the animal from the vegetable.

2 Aristotle is referring to an absurdity not fully expressed here.
The meaning appears to be that, although such a general definition
might be framed, it would be void of any helpful content or significance,
not being applicable to any particular form of reality.

56 ARISTOTLE S PSYCHOLOGY de amma

ducible species, thereby neglecting the particular meaning
in the general. The facts touching the soul are parallel
to this case of figure ; for both in figures and in animate
creatures, the prior ^ always exists potentially in the later,
e.g. the triangle is contained potentially in the square and
the nutritive power in that of sensation. We must, there-
fore, investigate the nature of the soul in particular things,

8 e.g. in a plant, a man, or a lower animal. And we must
415 « consider the cause of their order of succession. The

sensitive soul, for example, presupposes the nutritive, but
in the case of plants the nutritive exists apart from the
sensitive. Again, the sense of touch is presupposed by
all the other senses, but touch exists apart from them
and does not presuppose them. Many animals have no

9 sense of sight, hearing, or smell. Some that are capable
of sensation have also power of local movement, others
have not; finally the smallest number possess the power
of reason and understanding. Mortal creatures who
possess the power of reason, possess all the other psychic
faculties, but those which have each of these others do
not all have the power of reason, and certain of them do
not even possess imagination,'^ while still others live by
this alone. At another time we shall give an account of
the speculative reason. It is evident, however, that this
account touching each particular form of soul is also the
most fitting description of the soul in general.

^ The logically prior is meant.

'^ Imagination is of two sorts ((pavTaala aiadriTiK-fj and (pavraaia ^ovXcitikt}
^ XoyLariKT]), the one of which is the power of reproducing images of sense
or of reviving spent sensations ; the other is the power of constructing
the images that accompany thought, always, however, out of elements
ultimately drawn from sensation. Cf. Introduction, On Imagination.

CHArTER IV.

Iv one intends to make an investigation of the faculties of
the soul, it is necessary first to inquire into their several
natures, and then by the same method to inquire further
into other related problems. If, then, one is obliged to
describe the nature of each several faculty, e.f/. the
nature of the faculty of reason, of sense-perception, or of
nutrition, one must first be able to say what thinking
and sense-perception mean. For the activities and pro-
cesses are notionally prior to the faculties to which they
belong. If this is true, we must further observe the 2
objects of the activities before the activities themselves,
and we should for the same reason first determine our
position regarding these objects, e.g. regarding food, the
sensible, and the intelligible. First, then, we must speak
of food and generation. For the nutritive power is found
in all living things, and is the primary and most uni-
versal faculty of soul, by virtue of which all creatures 3
possess life. Its functions are to procreate, and to assimi-
late food. In all animals that are perfect and not
abnormal, or that are not spontaneously generated, it is the

most natural function to beget another being similar to

57

58 ARISTOTLE S PSYCHOLOGY de anima

itself, an animal to beget another animal, a plant another

plant, in order that they attain, as far as possible, the

415* immortal and divine^; for this is what every creature

4 aims at, and this is the final cause of every creature's
natural life. We understand by final cause two things :
the purpose aimed at, and the person who is served by
the purpose." Since it is impossible for an individual to
partake of the immortal and divine in its own continuous
life, because no perishable creature continues self-identical
and numerically one, it partakes therefore of the immortal
in that way in which it is able to share it, one thing in a
higher degree and another in a lower ; it does not itself
abide, but only a similar self abides ; in its continuity it
is not numerically, but only specifically, one.

5 The soul is the cause and principle of a living body.
These terms are used in several senses. Corresponding
to these differences, the soul is referred to as cause in
three distinct meanings ; for it is cause in the sense of
the source of movement, of final cause, and as the real

6 substance of animate bodies.^ That it is a cause in the
sense of real substance is evident, for real substance is in
every case the cause of being, and the being of animals is
their life, and soul is the cause and principle of life.
Furthermore, it is the complete realization that gives us
the real significance of a potential being. Soul is also

^ The only immortality possible for animals unendowed with Active
Reason is that of the perpetuation of their species through propaga-
tion.

'^ For example, the end or purpose of a lamp may be said to be either
(a) to give light, or (6) to serve the wants of the person who employs
the light.

• In other words, soul is used in the meanings of efficient, final, and
formal cause.

BK. II. OH. IV. SOUL AND KINAL CAIJSK 69

evid(3iitly cause in the seiiHc of final cauHo. For nature,
like rcuRon, acts witli j)urposo, and this j)urposo is its end.
In animals the soul is, hy virtues of its nature, a principle 7
similar to this. For the soul uses all natural bodies as
its instruments, the bodies of animals and the bodies of
plants alike, which exist for the soul as their end. JOnd
is used in two senses : the purpose, and the person or
thiniT which the purpose serves. Soul also means the 8
primary source of local movement. This power of local
movement is not possessed by all living creatures. Trans-
formation and growth are also due to the soul. For
sense-perception is supposed to be a kind of trans-
formation, and nothing is capable of sense-perception 9
unless it has a soul. The case is similar with growth
and decay. For nothing grows or decays by natural
processes unless it admit of nutrition, and nothing is
capable of nutrition unless it has a soul. Empedocles
ascribes downward growth to plants where they are rooted,
because the earth naturally tends downward, and upward 416 a
growth, because fire tends in that direction, and in these
respects is not right. For Empedocles does not employ
the terms up ' and ' down ' correctly. ' Up ' and ' down ' 10
are not the same for all things nor in all parts of the
universe, for roots are to plants what the head is to animals,
if one is to describe organs as identical or different in terms
of their functions. In addition, what principle is it that n
holds together these two elements of fire and earth,
tending, as they do, in opposite directions ? For they
will scatter asunder, if there be no hindering principle.
And if there is such a principle, it is the soul and the
cause of growth and nourishment. Some regard fire as 12

GO ARISTOTLE S PSYCHOLOGY db akima

the real cause of nutrition and growth. For this seems
to be the only body or element that feeds and increases
itself. One might, therefore, conjecture that this is the
element that causes growth and nutrition in animals and

13 plants. In a certain sense, it is true, fire is a co-ordinate
cause, but not the absolute cause, of growth ; this is rather
the soul. For the growth of fire is indeterminate so long
as there is material to burn ; on the other hand, in all
bodies developed in nature there is a limit and signifi-
cance to size and growth. These attributes ([of limit and
significance]) belong to soul, not to fire, to reason rather
than to matter.

14 Since the same power of the soul is both nutritive and
generative, we must first investigate nutrition ; for it is
by this function of nutrition that the faculty in question
is distinguished from other faculties. Nutrition is sup-

15 posed to take place by the law of opposites, although not
every opposite is nourished by every other, but such
opposites only as derive both their origin and their
growth from each other.' Many things are derived
from one another, but they are not all quantitative

16 changes, as e.g. healthy from sickly. Nutrition is not

^ The body is composed of all four elements and its nourishment
must include all of them. The animal waste is supplied out of these
several elements, which are themselves characterized by opposite
qualities, by means of the action of heat and cold. Blood is the final
form into which vital heat cooks the raw food. Aristotle makes really
little use of the physical explanations of the Pre-Socratics, who were
satisfied to explain all cosmical phenomena by such opposing forces in
nature as heat and cold, the moist and dry, the heavy and light, etc.
Although Aristotle still makes use of these ideas, in his dynamical
theory he sees the world full of final causes, while the purely physical
forces of the Pre-Socratics are merely the instruments employed by soul
or life.

iiK.ii. (MI. IV. THK SOUL AND NUTRITION 61

applied to these cases in the hhuw soriHe, for while water
is nutriment lor tire, lire dcx^s not nourish wut(;r. The
opposites of food and nourishment a})p('ar to aj)|)ly j)ar-
ticularly to sim])le hodies. There is, however, a dilliculty 17
here. For there are some who maintain that like is
nourished by like, as like is also increased by like, while
others, as we said, aflirm the converse of this, viz., that
opposites are nourished by opposites, on the ground
that like is incapable of being affected by like. Food,
however, undergoes transformation and is digested, and
transformation is in every case toward the opposite or 18
the intermediate. Further, food is affected by the body
which assimilates it ; the latter, however, is not affected
by the food, just as the builder is not affected by his 416^
material, although the material undergoes change through
him. The builder merely passes from a state of in-
activity into one of activity. The question whether
nourishment is to be understood to apply to the final 19
condition in which it is taken up by the body, or to its
original condition, creates a difficulty. If both are
meant, only in the one case the food is indigested and
in the other digested, it would be possible to speak of
nourishment conformably to both of the above theories ;
for in so far as it is indigested, we should have opposite
nourished by opposite ; in so far as it is digested, we
should have like nourished by like ; so that in a certain 20
sense, it is evident they are both right and both wrong.
Since nothing is nourished which does not share life, the
object of nutrition would be an animate body as
animate; so that food is determined by its relation to an
animate object and is not accidental. There is a

62 Aristotle's psychology deanima

21 difference between the nourishment and the principle of
growth ; in so far as the animate thing is quantitative,
the notion of growth applies ; in so far as it is a particular
substance, the notion of nourishment. For food pre-
serves a being as a substantial thing, and it continues to
exist so long as it is nourished. Nourishment is pro-
ductive of generation, not the generation of the nourished
thing, but of a being similar to it. For the former

22 exists already as a reality, and nothing generates, but
merely preserves, itself So then, such a principle of the
soul as we have described is a power capable of pre-
serving that in which this principle is found, in so far as
it is found ; nourishment equips it for action. When,

23 therefore, it is deprived of nourishment, it can no longer
exist. Since there are three distinct things here : the
object nourished, the means of nourishment, and the
power that causes nutrition, we shall say that it is
the elemental soul that causes nutrition, the object
nourished is the body which possesses this soul, and the
means of nourishment is the food. And since it is fair
to give everything a name in terms of its end, and since
here the end of the soul is to generate a creature like to
itself, the elemental soul might be called generative of

24 that which is like to itself The means of nourishment
is used in two senses, as is also the means of steering a
ship ; for one may refer to the hand, or to the rudder,
the ^ne being both actively moving and moved ; the other
only passively moved. All nutriment must be capable
of being digested ; heat is the element which accom-
plishes digestion. Everything animate, therefore, pos-
sesses heat. We have explained now, in outline, what

nK. 11. en. IV. PRINCIPLE OF NUTKITION 63

iiutriinont is. Tlio subjuct iiiumL ])e more minutely
treated later on in its proper place.^

' Siinplicius thinks the reference is to De (fene.r. auinuit. and Da yener.
ct corr. Sophoniufl refers to Detjener. anivial. (724a 14), The reference
can hardly bo to \Upl Tpo(f)?)<: as Hartht'leniy St.-llilairc (who follows
Trendolonburg) aupposcH. Thi.s latter treatiHo appears to liave origin-
ated in the Peripatetic School, but from the fact that it made the
distinction between veins and arteries it cannot have been Aristotelian,
and the reference in I)e sonm. 45G/' 5 must have been either to a pro-
jeoted work or to the early chapters of the Ifistor. anim. or to the
treatises enumerated by Simplicius. Cf. Zeller's Aristotle, Eng. tr..
Vol. I. p. 92, note.

CHAPTEE V.

Now that we have arrived at the foregoing conclusions,
let us discuss in general the entire question of sense-
perception. It consists, as we have said, in being moved
and affected ; for it is supposed to be a sort of internal
transformation. Some maintain that like is affected by
417 a like. In what sense this is possible and in what sense
impossible, I have explained in a general treatise On

2 Activity and Passivity} A difficulty is raised by the
question why it is that perceptions do not arise from the
senses themselves, and why it is that without external
stimuli they produce no sensation, although fire and
earth, and the other elements of which we have sense-
perception, are, either in their essential nature or in their
attributes, found in the senses. It is, therefore, evident
that the organ of sense-perception is not a thing in

3 actuality but only in potentiality. It is consequently
analogous to the combustible which does not itself
ijrnite without something; to set it ablaze. Otherwise
it would have burned itself and had no need of an

' Philoponus thinks the reference is to De gener. e( corr. (cf.

3ti36 ff.).

64

UK. n. CM. V I'OTKNTIAL AND A(VrUAL 65

active iin\ Inasmuch ns wo say that percoiviii}^ is
usetl in two iiKMinings (r.f/. we call the caj)acity to
hear and see, hearin<^' and si^dit, althon^di they may
chance to be dormant, and we a])|)ly the same terms
where the senses are actively exercised), so sense-
perception also would be used in two senses, the one 4
potential and the other actual. First of all let us
understand that the terms afHection, motion, and activity,
are used in the same meaning. For motion is a sort of
activity, although incomplete, as we have said elsewhere.^
Everything is affected and set in motion by an active
agent and by something that exists in activity. There- 5
fore in one sense a thing is affected by like, in another
by unlike, as we have said ; for it is the unlike that is
affected, but after being affected it is like.

We must, further, make a distinction touching potenti-
ality and actuality, for we are now using these terms in
a general sense. There is a sense in which we speak of 6
a thing as knowing, as when we call man knowing,
because man belongjs to the class of creatures that know
and are endowed with knowledge. There is another sense
in which we speak of a man as possessing the particular
knowledge of grammar. In each of these cases a man 7
possesses knowledge potentially, but not in the same
sense ; the former is knowing as belonging to a certain
genus and as having a native endowment ; the latter is
knowing in the sense of being able to exercise his know-
ledge at will, when nothing external prevents. In a still
different sense there is the man who is actually exercising
his knowledge, and is in a condition of complete realiza-

^Phys. 2016 31, 2576 8.
E

66 Aristotle's psychology deanima

tion, having in the strict sense knowledge of a particular

8 thing, as e.g. A. The first two know in a potential sense ;
the one of them, however, knows when he is transformed
through a discipline of knowledge, and has passed re-
peatedly out of an opposite condition ; the other knows

417^ in the sense of possessing arithmetical or grammatical
science ;^ and their passing from non-actual to actual

9 knowledge is different. Again, neither is the term ' pass-
ivity ' used in an absolute meaning : in one meaning it is
destruction by an opposite principle ; in another meaning,
it is the preservation of the potentially existent by means
of the actual and similar, just as potentiality is related to
actuality. That which possesses potential knowledge, for
instance, comes to the actual use of it — a transition that
we must either not call transformation (for the added
element belongs to its own nature and tends to its own
realization), or else we must call it a special kind of
transformation. It is, therefore, incorrect to speak of
thinking as a transformation when one thinks, just as the
builder is not transformed when he is building a house.

10 That which conduces to actualization out of a potential

^ These three forms of knowledge illustrate three stages in the
passage from undefined potentiality {bvvafXLs) to complete and definite
actuality (euepyeia). From mere rational potentiality, in which one has
no definite latent knowledge, one passes into a knowing state by
repeated application to a given science, and so from a non-knowing
condition into a knowing one. On the other hand, if one possesses a
particular science, as grammar, one has definite latent knowledge and
passes into active knowing, not by acquisition, but by applying what
one possesses in a dormant or inactive state. As a specific potentiality
it represents a higher stage in the progress towards actuality, which in
this case is the active exercise of specific knowledge. The primary
potentiality is a person teachable, the second a person taught, and the
actuality is a person actively employing what is taught.

UK. II. ("II. V. SKNSATION ANi» riioucii'r 07

stalo in the uiiittcr of reason in;^' ami Linnking iw not fairly
called teaching, but imiHt be giv(!n another nanu\ Again,
that which passes out of a potential state \>y learning or by
acqniring knowledge at the hands of what actually knows
and can teach, must either not be said to be affected as
a passive subject, or we nuist admit two meanings of
transformation, the one a change into a negative condi-
tion, and the other into a positive condition and the
thing's natural state.^

The first change" in the sentient subject is wrought u
by the generating parent, but after birth the creature
comes into the possession of sense-perception as a species
of knowledge. Active sensation is used in a way similar
to active thinking. There is, however, this difference,
that the objects which produce sensation are external,
£.g. the visible and the audible, and similarly other
sensible qualities. The reason for this is that active 12
sense-perception refers to particular things, while scientific
knowledge refers to the universal. These universals, how-
ever, are, in a certain sense, in the mind itself. There-
fore it is in one's power to think when one wills, but to
experience sense-perception is not thus in one's power ;
for a sensible object must first be present. This also holds
good of those sciences which deal with sensible realities,
and for the same reason, viz. because these sensible

^ AiddeaLs signifies a transitional condition and ^'|(s a permanent,
natural state. The former is either mere potentiality or an imperfect
stage in the passage of a thing towards its natural realization. As such
it represents a condition of privation or negation [aTeprjTtKr]), compared
with the positive, completed state at which a thing's nature aims.

'^ By ' first change ' is here meant the native endowment with the
potentiality to perceive and know.

68 Aristotle's psychology deanima

13 realities belong to the world of particular and external
phenomena.

To go into the details of these questions would be
more suitable at another time. For the present so much
may be regarded as fixed, viz. that the term ' potential '
is not used in any absolute sense, but in one case its
meaning is similar to our saying that a boy has in him
the potentiality of a general, and in another case to our
saying that a man in his prime has that potentiality — a
distinction which also applies to the capacity for sense-
H perception. Inasmuch as this distinction has no particular
418^ name in our language, although we have remarked that
the things are different and how they differ, we must
simply employ the terms affection and transformation as
applicable here. That which is capable of sense-per-
ception is, as we have said, potentially what the sensible
is actually. It is, therefore, affected at a moment when
it is unlike, but when it has been affected it becomes like
and is as its object.^

^ In other words, sensation represents an * affection ' or impression,
and is the transformatiou of a potentially perceiving into an actually
perceiving subject, in which case the sensible object is also converted
or assimilated into a knowledge-form. In this sense it is made like
the perceiving subject.

CHArXEK Yl.

In discussing any form of sense-perception we must
begin with, the sensible object. The 'object of sense'
is used in three meanings, two of which touch the
essential nature of sensation and one its accidents. Of
the two first-named, one applies specially to each par-
ticular sense, the other is common to them all. By
' peculiar object of sense ' I mean a sense-quality which 2
cannot be apprehended by a sense different from that
to which it belongs, and concerning which that sense
cannot be deceived, e.g. colour is the peculiar object of
vision, sound of hearing, flavour of taste. Touch,^ how-
ever, discriminates several sense-qualities. The other
particular senses, on the contrary, distinguish only their
peculiar objects, and the senses are not deceived in the
fact that a quality is colour or sound, although they may
be deceived as to what or where the coloured or sonorous
object may be. Such qualities are called the peculiar 3
objects of particular senses, whereas common objects are

1 Touch distinguishes the properties of body as body [De an. 423ft

27), more specifically the qualities hard and soft, moist and dry, hot

and cold, smooth and rough. Moreover, taste is, according to Aristotle,

a kind of haptic function.

69

70 Aristotle's psychology deanima

motion, rest, number, form, magnitude. Properties of
the latter kind are not the peculiar objects of any sense,
4 but are common to them all. Motion is apprehended by
touch and by sight. A thing is an object of sense
accidentally, e.g. when a white object proves to be the
son of Diares. The latter is perceived accidentally, for
the person whom one perceives is an accident of the white
object. Therefore, the sense as such is not alBfected by
the sensible object ([as a person]). To the objects of sense,
strictly regarded, belong such properties as are peculiarly
and properly sense-qualities, and it is with these that the
essential nature of each sense is naturally concerned.

CHAITEK VI 1.

The object of vision is the visible. The visible is colour
and something whose notion is expressible, but for which
there is no single definite name.^ What I mean will be
best explained as we proceed. The visible, then, is colour,
and this is dittused upon that which is in itself visible,^
and by visible ' in itself,' I do not mean notionally
visible, but something which has in itself the cause of the
visible. All colour has the power to move the actually ^jg^
diaphanous and herein consists its nature. Therefore colour 2
is not visible without light, but every particular colour is
seen in the light. For this reason we must first explain
what light is. Light is something diaphanous. By dia-
phanous I mean that which is visible, though not in itself and
absolutely, but only by means of an agent, namely colour.
Of such nature is air and water and many other bodies. 3
Water and air are not diaphanous as water and air, but
because there is in both these elements the same property
that is found in the eternal empyrean. The activity of

^Such phosphorescent and scintillating substances as mushrooms,
horn, fish-heads, etc. Vid. De an. 419a 5.

^ Colour is not a substance but a property, a property diffused on the
surface of a body and has the power to move a diaphanous medium. It
is the coloured thing which is the substance or the per se visible,

71

72 Aristotle's psychology deanima

4 this diaphanous, as such, is light. But where the
diaphanous exists only potentially, there is darkness.
Light is the colour, as it were, of the diaphanous, when
the diaphanous is made really so by fire or by some such
agent as the supernal body, for in the supernal body

5 there is something which is identical with fire. The
nature of the diaphanous, therefore, and of light has been
explained. Light is, namely, neither fire nor in a word
any body nor the efflux of any body^ (for this would then
also be a body), but it is the presence of fire or some
such agent in a diaphanous medium. For two bodies can-
not occupy the same place at the same time. Light appears
to be the opposite of darkness. Darkness is the privation
of a condition of the diaphanous, the presence of which

6 condition is light. Empedocles^ is wrong, as is every one
else who has held a like theory, in thinking that light
moves itself and at some time or other projected itself
into the interval between the earth and the surrounding
space, without our being conscious of it. For this is
contrary to plain reason and to observed facts. In
a small space, the fact might escape us, but in an
interval that extends from east to west, to claim that the

7 fact escapes our notice is asking too much. It is the
colourless that is receptive of colour, and the non-
sonorous that is capable of sound. Colourless are the
diaphanous and the invisible, or that which is scarcely
visible, as for example, the dark. Of such nature is the
diaphanous, but only when it is so potentially and not

1 Plato, TimaeusGlC.

^ Burnet thinks that Empedocles was led to suppose that light takes
some time to travel, although its speed is so great as to be imperceptible,
by this theory of "effluences." Burnet, Early Greek Philos. p. 255.

liK. II. cii.vii. VISION AND ITS MKDIUM 73

actually. Vor l\\v same iiicdiuiu i.s Hoinetiine.s diirk and
soinctimos light. Not all objocts are viHihle in the light, s
but only tho peculiar colour of each object. For cerUiin 4i9«
objects are not visible in the light, but stimulate sensa-
tion in the dark,' as r.c/. those liery, shining phcinoniena
that have no class-designation such as mushrooms, horn,
and the heads, scales, and eyes of fish, while the peculiar
colour of none of these objects is seen. The explanation 9
of their visibility is subject for a different treatise than
the present. So much is now clear : it is colour that is
visible in light. Therefore without light colour is not
visible. For it is the essence of colour to set the
actually diaphanous in motion, and the diaphanous in
actuality is light. Clear evidence of this is the fact that 10
if one places a coloured object on the eye, it is not seen.
On the contrary, it is the diaphanous, as c.[/. the air,
which is stimulated by colour, and the sense organ is
stimulated by this contiguous medium. Democritus is
wrong, then, in supposing that if the medium were a
vacuum our vision would be accurate, even to the seeing
of an ant in the sky. This is impossible, for vision takes
place from the fact that the percipient organ undergoes n
an effect, and this effect cannot be produced directly by
the visible colour. So that there remains only the
supposition that it is produced by a medium, and conse-
quently there must be a medium. And were a vacuum
produced, there would not only be no accurate vision, but
no vision at all.^

^ Phosphorescent substances.

^ Aristotle says there are three things to be taken into account in sense-
perception — the organ, the object, and the medium, all of which are
^ondiciones sine quihus non. The medium of vision is the diaphanous or

74 Aristotle's psychology deanima

12 The reason why colour is visible only in the light has
been explained. Fire, however, is visible in both light
and darkness, and necessarily so, for it is by the agency
of fire that the diaphanous becomes diaphanous. The

13 same statement applies also to sound and smell. For
nothing when placed in actual contact with the sense-
organ produces the sensation of sound or smell, but by
means of odour and sound a medium is set in motion and
through this the sense organ in each case is affected.
But if one should place a sonorous or odorous object on
the sense organ itself, no sensation would be produced.
In the case of touch and taste, similar conditions hold
good, although not apparently. The reason for this

14 will be evident later. The medium for sound is the
atmosphere ; the medium for smell has no name. It is
an element that is common to air and water, and as
the diaphanous is related to colour, so there is a some-
thing in water and air similarly related to an odorous
body. For aquatic animals appear to be capable of the

41^^ sensation of smell. But man and the respiring land-
animals smell only in so far as they employ inspiration.
The cause of these phenomena will be explained later on.

property of translucence found in air and water, a quality analogous to
that found in the aether of the empyrean and in fire. The media of
hearing (4196 18, 420a 11) and smell are air and water, and the medium
of touch (and taste) is the flesh. In this connection it is to be noted
that, while both air and water serve as media for smell, only air is a
medium for man, and only water a medium for the aquatic animals.
Man cannot smell in water. Cf. De an. 4216 8, 15, 19 ; 422a 4 ;
Hist. anim. 534a 11.

CHAITEPt VI 11.

Let us now first of all discuss the subject of sound and
hearing. Sound is twofold. It is one thing in actuality,
and another in potentiality. Some things, we say, are
incapable of sound, such as a sponge or wool, others are
resonant, such as bronze and bodies that are hard and
smooth, because they can emit sound ; that is, they have
the power to create an actual sound through mediation 2
between the resonant object and the hearing. The actual
sound is always produced by something in reference to
something and in a medium.^ A blow is the producing
cause. It is, therefore, impossible for an object, taken
alone, to produce a sound, for the striking agent and the
struck object are different. Thus the sonorous body pro-
duces sound by its relation to another body. A blow is 3
impossible without movement, and, as we have said, sound
does not result from a blow upon any haphazard object.
Wool, e.g. when struck produces no sound, but bronze

1 Theophrastus and the peripatetic commentators introduced the
term dirjx^^ to describe the medium of sound and dioa-fiov to describe the
medium of smell. Cf. Themistius, ed. Spengel, p. 115. Simplicius
Comment in lib. De an., 419a 32. Philoponus Comment iii lib. De an.
(Ed. Acad. Reg. Bor.), 355. U.

75

76 Aristotle's psychology deanima

and whatever is hard and smooth do. Bronze is resonant
because it is smooth. Hollow bodies, by reverberation,
produce many reports after the first one, because the air,
when it is once set in motion, can find no egress.

4 Furthermore, audition takes place in air and water, but
to a less degree in the latter. But neither air nor water
is the main thing in the case of sound. The percussion
of solid bodies against each other and against the air
must take place, and this takes place when the smitten

5 air resists and is not dissipated. Therefore if it is struck
quickly and violently it produces sound, for the motion of
the striking agent must anticipate the dispersion of the
air, as if one were to strike a pile or rapidly shifting
chain of sand. An echo is produced when from the air
which is made unitary by means of the vessel that confines
it and keeps it from dispersion, an oncoming mass of air
is driven back again, like a rebounding ball.^ An echo is

6 apparently produced constantly, only it is not audible,

^ Sound, according to this explanation, is produced by smooth,
resisting bodies. The production of sound depends on the following
conditions : (1) an object to be struck, (2) a striking agent, (3) a com-
municating medium, (4) a hearing organ, (5) the delivery of the blow
in such way that the diffluent air (medium) may not be dissipated and
so conduct no sound. When the air is smitten quickly and vigorously,
it is compressed before it can yield, and so emits a report, as the com-
pressed air in a bladder makes a report on bursting (an illustration
cited by Wallace from Pacius). An echo is the repercussion of air
from the resisting side of a vessel or place that obstructs the dissipation
of air, whereby instead of becoming soundless it is thrown back, like a
ball, and made to sound again. The disturbed air communicates with
the air in the ear, which being fast immured cannot be dissipated,
but interprets without variation the reports brought to it by the move-
ments of the external air. Disturbances in the condition of the internal
air, e.q. through yawning, modify the accuracy of hearing. We,
also, for the same reason hear better when inhaling than when exhaling
{De gener. anim. 781o31).

MK. II. ni. VIII. SOUND AM) ITS MKDIIJM 77

for tlu' sjiiUL' c-onditioiis hold -^ood of both sound aud
li^ht. Li^ht is oonsUinlly rctlocted (otherwiHc li^dit
would not be loun*! (werywhore, l)ut there would be
darkness outside the re«^ion illuminated by the sun), but
the retlection is not sinnlar to that which is caused by
water or bronze or any other polished solid, where a
shadow is cast whereby the light-area is delimited. A 7
void is correctly regarded as a chief factor in hearing.
Now, the air appears to be a void, and this, when it
is moved as a single and continuous element, is what
produces hearing. But, because of the swift dissipation
of the air, no sound arises unless the object struck be
smooth. In this case, however, the air by reason of 4200-
the even surface, is made one throughout, for the surface
of a smooth body is one throughout.

A body is sonorous when it is capable of setting in
motion up to the organ of hearing the single and con-
tinuous air. Hearing is naturally related to the air, aud
owing to the fact that sound is in the air, the inner air 8
is set in motion by the moving outside air. Therefore,
an animal does not hear in all parts of its body, neither
does the air penetrate everywhere. And the psychical
organ that is to be stimulated does not contain air in all
its parts. The air in and for itself is, by reason of its
facile dispersion, non-sonorous. But when it is restrained
from dispersion, its motion produces sound. The air 9
within the ears is so deeply immured as to be in itself
immovable, in order that it may detect all distinctions in
communicated motions. For these reasons we hear in
water, because the water has no access to the congenital
air, nor does it penetrate even into the ear because of the

78 Aristotle's psychology deanima

latter's convolutions. When, however, this does happen,
hearing ceases. Neither do we hear when the membrane
io is diseased, just as the eye has no vision when its cornea
is diseased. A test as to whether hearing is intact or not
is found in the ears' continually resounding like a horn.
The air in the ear has its own peculiar motion, although
sound is foreign to this internal air and is not one of its
properties. It is for this reason that we speak of hearing
by means of a void and resonant organ, because we hear
by means of something which contains confined air. The

11 question arises whether it is the striking agent or the
object struck that produces sound. Or is it both of
these, but each in a different sense ? Sound is a sort of
motion of an object which is capable of being moved in
the same way as the particles that rebound from smooth
surfaces when one strikes them. Not every object, as
has been said, produces sound when struck or when
striking another object, as e.g. in the case of one sharp
point striking another. On the contrary, the object that
is struck must be smooth, so that the air may be thrown

12 off and agitated in a mass. Distinctions in resonant
bodies are discernible in the actual sound they pro-
duce. As without light no colours are visible, so without
sound the acute and grave are not discernible. These
terms are employed metaphorically and are drawn from

13 the tactual sense. The acute stimulates sensation quickly
and strongly, and the grave slowly and in a small degree.
It is not the acute,^ however, that is quick nor the grave
that is slow, but merely the motion of the one is called

'Perhaps a criticism of Plato {Timatns 67 C), as Trendelenburg
thinks.

i.K. n. en. VIII. DEFTNTTTON OF \'(M('K 79

quick by rcafloii of its awil't ju^tioii nn ihc sense, and tlic
other is culled slow Ity reason of its tardy aeti(jn. Tin-
analogy appears to apply to acute and dull in the sense
of touch. The acute (.;/. pricks and the hlunt ])ushes, 420^
as it were, because the motion of tin; one is (piick and of
the other slow, so that the effect of the; one takes place
swiftly and of the other tardily. Let so much sufilce for 14
the discussion of sound.

Voice is the sound produced by a living b(;ing. No
inanimate thing has voice, unless one speaks metaphori-
cally, as e.g. the flute, lyre, and other inanimate
instruments are said to have a certain range, melody, and
expression, properties which are possessed also by the
voice. Many animals are without voice, as the
bloodless animals, and, amongst the sanguineous, fishes.
This has its good reason, seeing that sound is a move- 15
ment of the air. Fishes that are said to have voice,
such as those in the Achelous,^ produce a sound by
means of their gills or some such organ. Voice is the
sound made by a living creature, and made not by any
accidental organ. But since nothing emits sound unless
there is a striking agent, a thing struck, and a medium,
viz. air, it would be reasonable to suppose that only
those animals that breathe air possess voice. Now
nature employs respiration for two purposes, just as she 16
employs the tongue both for the function of taste and of
speech, of which functions taste is necessary (and therefore

^Referred to in Hist. anim. (Bk. IV. Ch. 9, 5356 18) as Kairpos, said
to make a grunting noise, which probably suggested the name {Kairpos
meaning primarily a wild boar). It is not known to what fish this
refers, although it has been thought to be the capros aper of the Aegean
Archipelago. Cf. Aubert and Wimmer's Aristoteles' Thierkuiide, p. 130.

80 Aristotle's psychology deanima

is found in all animals generally), whereas the communi-
cation of thought is given for the ends of higher living.
So it is with respiration, which performs a function in
reference to the internal warmth, and as such is neces-
sary for living (the reason will be explained elsewhere),
and another function in reference to speech, where it
subserves the ends of higher living. The windpipe is the
'7 organ of respiration, and this organ in turn subserves
another, the lungs, and it is in virtue of the latter that
land animals have more heat than others. The pericardiac
region first of all needs respiration,^ and, therefore, it
is essential that the air be inspired inwards. And
so it is the percussion of the inspired air, directed by
the soul in those inward parts, against the windpipe,
i8 as it is called, that constitutes voice. Not every sound
of an animal is voice, as we have said (for it is possible to
make noises with the tongue or such as people make in
coughing), but the impact of the air must be animate
and combined with some idea in order to be called voice.
For voice is significant sound and not merely the sound
of respired air, as is the case in coughing. On the
contrary, the animal by means of this respired air pro-
421 a duces an impact of the air already in the windpipe against

^ The organs through which cooling is effected are the brain and
lungs, and in the case of fishes the gills. The need of cooling is
found in different degrees in different animals. Bloodless animals need
it least. Insects do not inhale, but they are provided with a substitute
for inspiration in a supply of congenital air. {De respirat. Ch. 9, 474^
25 ff. ) The lungs of mammals contain most blood, while the lungs of
birds and amphibious creatures are more spongy and contain most air,
and the latter can consequently live longer without inspiring air.
The air is carried through veins that lead from the lungs to the heart.
Hi«L animal. Bk. I. Ch. 17, 496a 27 ff.

UK. II. (MI. Mil. VOCAL UTTKKANCK Hi

the tradiea ilHoU". 'I'liis is proven l)y Llic iinj)os.sil)ilily 19
of vocal utterance when we neither inhale nor exliale l)Ut
simply hold our hreatli, l)ecause in holdin;^ the broatli we
thereby disturb this vocal process. Also, we see from
this why it is that the lishes have no voice, being, as
they are, without a windpipe. Tlu^y lack this or«,Mn,
because they are incapable ol' inhalinii, or exhaling air.
The explanation of this is matter for a different treatise.

CHAPTEE IX.

Smell and its object are less easy to define than the
foregoing senses, for the nature of smell is not so clear
to us as is that of sound and colour. The reason for this
is the fact that this sense with us is inaccurate and less
perfect than in many animals. Man has a poor sense of
smell, and smells no odorous object without painful or
pleasant association, because the sense-organ does not

2 sharply discriminate qualities. It is probable that the
hard-eyed ^ animals discriminate colours in the same
way, and that distinctions in colour are not clear to them

3 except as they have the feeling of fear or not. So it is
with smell in the human race. Smell has apparently
some analogy to taste, and the species of flavours corre-
spond to those of odours; but our sense of taste is more
accurate because it is a sort of touch, and the sense of
touch is the most accurately developed of all the senses
in man. In the case of the other senses, man is inferior
to many animals, but in discriminations of touch he is

4 far superior to the others. For this reason man is the
most intelligent animal. A proof of this is the fact that
within the human race the good or bad native endow-

^ Hint. anim. ii. 13, 505a 35; iv. 10, 5376 12; De part. amm.
ii. 13, 6576 34. Such animals have no eyelids, as e.g. crabs.

82

r.K. II. (II. IX. THK SKNSK OF HMKLL 83

iiient of iiidivicluals dojurnds upon this sense or^an, and
no other. Men who have hard llesh are poorly endowed
intellectually, men vvlio have soft flesh are <,dfted.^

As one Havoiir is sweet, another bitter, so it is with 5
smells. AlthouL^di in some eases smell and llavour
correspond to each other, — I int;aii, for example, where
we have a sweet smell and a sweet flavour, — in other
cases they are contraries. In like manner we refer the
qualities of pungent, harsh, piquant, and oily to smells as 6
well as to flavours, but, as we have said, owing to the
fact that smells are not so clearly discriminated as
flavours, these terms are borrowed from taste on account
of similarity in the sense objects. For the smell of 421 d
saffron and honey is sweet, and the smell of thyme and
similar herbs is pungent. The same holds good of other 7
qualities. Further, just as hearing and each particular
sense distinguishes its own object, in the one case the
audible and inaudible, in another case the visible and
invisible, so also smell distinguishes the odorous and
inodorous. And the inodorous is so called, in one case,
from the fact that it is totally incapable of yielding
smell ; in another case because the smell is faint or
indefinite. Similarly one employs the term insipid.

Smell is transmitted through a medium, such as air or 8
water. For aquatic animals appear to smell ; so, too,
sanguineous and bloodless animals, and the birds of
the air, have this sense. Some of the latter are endowed
with the power of scent and mark their prey from afar.
It seems doubtful, therefore, whether the process of smell 9
in all these animals is alike. Man smells while inhaling,

^Compare our expressions 'thick-skinned,' 'hide-bound,' etc.

84 ARISTOTLE 8 PSYCHOLOGY de anima

but without inhaling and while exhaling or holding his
breath, he does not smell, whether the object be remote

lo or near, not even if it be placed in the nose itself. That
an object when placed upon the sense-organ itself is not
perceived, is a fact common to all the animals. But not
to perceive odours without inhaling is peculiar to man, as
may be proven by experiment. Were it not so, the
bloodless animals, inasmuch as they have no respira-
tion, would have to possess a sense beyond those already

u named. But this is impossible, if it is true that they
perceive smells, for the perception of the odorous, whether
pleasant or unpleasant, is the sense of smell. Further-
more, as these animals appear to be destroyed by strong
fumes, just as man e.g. is destroyed by pitch, sulphur,
and similar fumes, they must have the sense of smell,

12 although they do not respire. The organ of smell in
man appears to differ from that in the other animals, just
as his eyes differ from those of the hard-eyed animals.
For the eyes in man have a protection and, as it were, a
sheath in the eyelids, and without moving or opening
these he does not see. Whereas the hard-eyed animals
have no such protection, but see at once whatever comes

13 into the field of vision. So also the organ of smell in
422 a some animals is uncovered, as the eye is ; while in others

that respire, it has a covering, which opens in inspiration

14 and by the dilation of veins and pores. For this reason
the animals that breathe do not smell in water. For in
order to smell they must inhale, and in water this is
impossible. Smell is a property of the dry, as flavour is
of the moist, and the organ of smell is potentially
analogous to its object.

CHAPTER X.

The sapid is a tactual j)roperty, and this explains the
fact that it is not perceived through the medium of any
foreign body.^ For neither is the tactual so perceived.
The body in which flavour, i.e. the gustable, is found
consists in something moist as its matter, and this moist
element is something tangible. Consequently, if we were
in the water and something sweet were thrown into it,
we should perceive it. The sensation, however, would
not have been produced in us through a medium, but by
the mingling of the sweet with the moist, as is the case 2
with a beverage. Colour, on the other hand, is not per-
ceived by means of its being mingled with anything, nor
by means of emanations. There is in the case of taste
no medium ; in other respects, however, as colour is to
the visible, so is taste to the sapid. Nothing can stimu-
late the sensation of flavour apart from the moist, but an

^ The medium of touch is the flesh. The medium of taste is also the
flesh, more particularly the tongue and throat (if Aristotle concurs in
the popular opinion represented by Philoxenus, cf. Eth. tiicom. iii. 10.
10. 1118a- 33). These two senses, consequently, apprehend qualities
only through immediate contact, while sight, hearing, and smell operate

at a distance through the media of air and water.

S5

86 ARISTOTLE S PSYCHOLOGY de anima

object must possess moisture either actually or potentially,

3 as does salt. For salt is easily soluble, and melts on the
tongue.

As sisfht is discriminative of the visible and invisible
(for darkness is the invisible, and on this, too, sight
exercises judgment), further of the extremely dazzling
(for this is also invisible, but in a different sense from
darkness), so, too, hearing is discriminative of sound and
silence, of which the one is audible and the other
inaudible, and of the crashing sound, as sight is dis-
criminative of dazzling brightness (for as a tiny sound is
inaudible, in a certain sense a great and crashing sound
is also inaudible). The term invisible is used, on the
one hand, in an absolute sense, and means the same as
the term impossible does in other cases ; on the other
hand, it is used in the sense of what is naturally meant
to be seen, but is not seen, or only imperfectly seen,
just as one applies the terms footless and seedless to
animals and fruits that are imperfect. So also is taste

4 discriminative of the gustable and non-gustable ; the
latter is that which has an insignificant or indistinct
flavour, or a flavour that is subversive of taste. The
potable and non-potable seem to be the final principles
of taste ; taste implies both of them. The one is, how-
ever, indistinct or destructive of taste, while the other is
natural to the sense. The potable is common to the

422 /' senses of touch and taste. Since the sapid is moist, it is
necessary that the sense-organ be neither actually moist
nor incapable of becoming moist. For taste is affected

5 by the sapid object as sapid. Consequently it is
necessary for the organ of taste to be capable of becoming

UK. II. (!ii. X. THK ISENHK OK TASTE 87

moist, witlumt injury and without becoming; intrinHJcally
nioiHt.^ A proof is tho fact that thn ton^me, when it is
very moist or very dry, is incapable of perc(uving the sa})id.
For in this case there arises merely a tactual impression
of the simple licpiid, just as when one first tastes a strong
flavour and then essays another, or as everything seems
bitter to an invalid because his tongue is full of this 6
bitter moisture. The varieties of flavours, as in the case
of colours, are partly simple opposites such as sweet and
bitter, partly the affiliated qualities oily and salty, and
the intermediate qualities of pungent, harsh, astringent,
and acid. For these seem to include approximately all
the distinctions in flavours.^ So then the sapid sense is
potentially of the same character as the sapid object
which actually produces the sensation of taste.

^ Aristotle applies here to taste the metaphysical doctriue of poten-
tiality and actuality which he employs everywhere in the explanation
of organic life. All change is a transition from a potential state into a
state in which a thing finds its end realized or in process of realization.
So the sense of taste is only potentially taste until it is stimulated. In
this process of actualization or realization the organ assimilates an
objective quality and converts it into a subjective one, to use modern
terminology, and this process Aristotle describes as the "sense becom-
ing like the thing," or, specifically, the " capacity of the organ of taste
to become moist, without being converted into moisture, or becoming
intrinsically moist." The potentiality of the organ refers only to the
assimilation of a property or sense-quality.

-Aristotle distinguishes two fundamental colours, black and white
(which on surfaces correspond to darkness and light), and two funda-
mental tastes, bitter and sweet. Including black and white, there are
seven primary colours, all of whose elements, however, are found in
black and white, and they are produced from these two by processes of
mixture. These colours are white, black (including grey, De sensu,
442a 22), yellow, red, violet, green, and blue. Analogously the seven
primary tastes are based on bitter and sweet. The flavours are : sweet
(including the fat or oily), bitter, salt, harsh, pungent, astringent, acid
(cf. De sensu, 4. 442a 12).

CHAPTEK XL

The same kind of reasoning applies to the tangible and
the sense of touch. If touch is not a single sense but
several, then tangible objects must also be manifold.
There is some doubt whether touch is manifold or
unitary, and it is uncertain what the sense-organ is
which apprehends the tangible. Is it the flesh in
man, and in other animals something analogous to flesh,
or is the flesh only the medium, while the primary

2 organ is something different and internal ? Every
sense appears to apprehend only one contrary, e.g. sight
senses black and white ; hearing, acute and grave ; taste,
bitter and sweet. In touch, however, are found many
opposites : hot and cold, moist and dry, hard and soft,
and other similar opposites. There appears, however, to

3 be a solution for this difficulty in the fact that several
opposites apply to the other senses also, as e.g. in sound
there are not only the properties acute and grave, but
also large and small, and smooth and hard, and similar
qualities are applied to the voice. Similarly, different dis-

4 tinctions are applied to colour. But what forms the single
substrate for touch, as sound does for hearing, is not clear.

88

i.K. II. < II. \i. TUK SKNSK OK TOUCH 89

Another quostion is whether the sen.sc-ori^an jh internal
or not, or wlictlicr the IUihIi iinniediutely HenseH touch-
tlualiticH. The fact that sensation is .simultaneous with .425 a
eontact is no proof here. For as a matter of fact, if one 5
should prepare a memhrane, as it were, and draw it over
the flesh, one would still have the sensation of touch at
the moment of contact, and yet it is plain that the sense-
organ is not in the membrane. Even were it grown
together with the ilesh, the sensation would only the
more quickly penetrate it. Consequently this part of the 6
body seems to be related to us as the air would be, were
it grown to us round about. For we should then have
to perceive sound, colour, and smell in each instance
by means of a single sense-organ, and sight, hearing,
and smelling would in that case have become a single
sense.

However, as a matter of fact, since the media through
which sense-movements are transmitted are different, the
sense-organs themselves are different. In the case of 7
touch this is not clear ; for it is not possible that a living
body should consist of air or water ; it must be a solid
body. It remains that it is a body composed of earth
and those two former elements, air and water, in such way
as it is intended flesh and what is analogous thereto
should be. Consequently, the body ([i.e. the flesh]) must
be the natural medium for the sense of touch, by which the
several sensations are mediated. That they are several 8
is evident from the character of touch on the surface of
the tongue. For the tongue, as a single organ, dis-
cerns all tactual and sapid qualities. Further, if the
rest of our flesh were to discern sapid qualities, touch

90 Aristotle's psychology deanima

and taste would be regarded as one and the same sense.
But as a matter of fact they are regarded as two, because
they are not convertible.
9 Since body has depth, i.e. the third dimension, wherever
there is an intermediate body between two other bodies
the question might be raised whether it is possible for
these two bodies to be in contact with each other. Now,
neither the moist nor the fluid is incorporeal, but each
must necessarily be water or contain water. But objects
which are in contact with each other in the water, inas-
much as their extremities are not dry, must have water
between them, in which their outer circumferences are

10 submerged. Now, if this is true, it is impossible for two
objects in water to be in contact with each other. The
same holds good of the air (for air is conditioned in the
same way towards the objects in it as water is towards
objects in water, only in the former case the conditions are
more elusive for us ([who live in an atmospheric medium]),

11 just as aquatic animals fail to observe that the fluid is in
423 6 immediate contact with the fluid. A further question then

arises, whether the same process of sensation applies to all
senses alike, or whether in different senses the process is
different, just as touch or taste was seen to function by
means of immediate contact, while the other senses function
from a distance. This last distinction is not real, but
both the hard and soft we perceive through media, as we
do also the sonorous, the visible, and the odorous; in the
one case we have objects at a distance, in the other, close

12 at hand. This is the reason why the medium eludes our
observation. For we do sense everything through a
medium, but in the case of things close at hand, the

UK. II. CM. \i. Till-: MKDIUM OF TOUCH 91

oxistenco of Llw mcMliuiii (Nscapes uh. And yvX, us we
said above, wore we to perceive iill lun^Mblc! (jUJilities
throu<^'h the mediuiii of a menihnvne without knowing' tlifit
a nuMlium intervened, we should thcin he in the Hanie
condition as wo now are in th(^ media of air and water.
For we appear now to be in contact with things them-
selves, and not to ap[)r(^}iend them throuj^h a medium. 13
The tangible, however, dili'ers from the visible and audible
in that we perceive the latter by the medium producing
a certain effect on us, while qualities of touch we do not
perceive by means of the medium but simultaneously
with it, as a man who is struck through his shield. For
the struck shield does not strike him, but rather shield
and man are simultaneously struck. In a word, flesh 14
and the tongue seem to be related to the sense-organ as
air and water are severally related to sight, hearing, and
smell. For were the sense-organ itself brought into con-
tact with the object, sensation would not result either in
the one case or the other, just as little as vision would
result were one to lay a white object on the surface of the
eye. By which it is evident that the organ of touch 15
must be internal,^ for in this way it would be parallel
with the other senses. When objects are placed upon
the sense-organ, sensation does not result ; on the other
hand, when placed upon the flesh, sensation does result.
Flesh must, therefore, be merely the medium of touch.

The distinctions of body as body are tactual. By dis- 16
tinctions I mean such as characterize the elements — viz.
warm and cold, dry and moist, concerning which we have

1 The organ of taste and touch is the heart ; the media, as already
explained, are the tongue and flesh.

92 Aristotle's psycholoc4Y deanima

spoken in an earlier treatise On the elements} The sense-
organ which perceives these distinctions is touch, and the
part in which the sense of touch, as we call it, is primarily
found is potentially what tangible objects are actually.

1 7 For sensation means being affected in a certain way ; so
424 a that whatever makes another thing to be in reality like

itself does so by virtue of that thing's having this nature
in potentiality. Therefore we do not perceive hot and
cold, hard and soft, in objects that have these qualities in
like degree as ourselves, but we perceive the excesses, as
if sense were a sort of mean between opposed sensible
objects. And hence it discriminates sensible objects.

18 The mean is capable of judgment, for it becomes in refer-
ence to each of the extremes another extreme. And as
that which is to perceive white or black must not itself
be actually white or black, but both of these potentially
(and the same holds good of other instances), so also in
the case of touch, it must not be either hot or cold in
itself. Furthermore, as sight was said to discriminate in

19 a sense both the visible and invisible, and the other
senses in like manner their opposites, so also touch
discriminates the tangible and intangible. And by
intangible I mean those things where tactual discrimina-
tions are quite indistinct, as e.g. in the case of air, and
those excesses of touch that are destructive of the sense.
Each of the senses has now been treated in outline.

^ De gen. tt corr. 3296 18-.3306 9. On the lost treatise ircpl arot.x'^iijjv
see Heitz, Die Verloreuen Schriften d. Arintoteles, p. 76.

CHArXElJ XII.

In reference to sensation in general we must understand
that a sense is capable of receiving into itself sensible
forms without their matter, just as wax receives
into itself the mark of a ring without its iron or
gold ; — it receives into itself a gold or bronze im-
pression, but not as gold or bronze. In like manner
also sense is impressed by every object that possesses
colour or flavour or sound, not in so far as each of
these objects bears a given name, but in so far as it has
such and such a quality and expresses an idea. The 2
organ of sense is fundamentally that in which this
power of being impressed exists. It has therefore an
identity with the object that makes the impression, but
in its mode of expression it is dififerent. Otherwise that
which perceives would be a sort of magnitude ; whereas
the mode of expression of the perceptive faculty and of
sensation is not magnitude, but only a certain relation
and potentiality of magnitude. From this it is clear
why excesses in sensible objects destroy the sense-organs. 3
For if the stimulus be stronger than the organ, then the
relation between them is destroyed, just as harmony and

tone are destroyed when the strings are struck too

93

94 Aristotle's psychology deanima

4 violently. Why is it, then, that plants have no sensation,
having as they do a certain psychical endowment, and
being affected by tangible qualities, for they experience

424 ^ e.g. cold and heat ? The reason is that they have no
mean in their nature, nor such a principle as is capable of
receiving into itself the forms of sensible objects ; on the

5 contrary they are affected materially. One might raise
the question whether a thing which cannot smell can be
affected by odour, or that which cannot see can be
affected by colour, and so on. Supposing that the object

6 of smell is odour, odour produces the sensation of smell,
if it produces anything at all ; so that nothing which is
incapable of smelling can be affected by odour. The
same reasoning applies to the other senses. Neither can
sentient beings be affected further than they are in each
case sentient. This is also evident from the following :
neither light nor darkness, sound nor smell, acts upon
bodies, but the media in which these qualities exist
may act upon bodies, e.g. it is the air which is
combined with thunder that rives the tree. Tangible

7 qualities, however, and flavours operate directly. If
this were not so, how could inanimate bodies be
affected and changed ? Do the other qualities then
act directly also ? Or is it rather true that not every
body is capable of being affected by smell and sound, and
those which are so affected are indefinite and unstable, as
e.g. the air ? For air emits odour as if it were affected by
something. What is smelling, then, beyond this being
affected by something ? Smelling surely means also
perceiving, whereas the air by being affected is only made
the ready object of perception.

BOOK THE rUIRD.

CHAITEU I.

That there is no additional sense beyond the five we

have enumerated (I mean sight, hearing, smell, taste, and

touch), one may believe from the following considerations.

Granted that we really have perception of everything for 2

which touch is the appropriate sense (for all the qualities

of the tangible as such are apprehended by touch), it is

necessary that if any sensation is lacking, some organ

must also be lacking in us. Whatever we perceive by

contact is perceived by the sense of touch, with which we

are endowed. On the other hand, whatever we perceive

through media and not by direct contact, is perceived by

simple elements, such as air and water. The conditions

here are such that if several sensible objects which differ 3

from each other generically are perceived by a single

medium, then anyone who has a sense-organ analogous

to this medium must be capable of perceiving these

several sense-objects. For example, if the sense-organ

is composed of air and the air is the medium of both

sound and colour, the organ would perceive both these

sense- qualities. If, on the other hand, several elements

are mediators of the same sense-qualities, as e.g. colour is 425 a

95

96 Aristotle's psychology deanima

mediated both by air and water (for both are diaphanous),
then the organ which contains one of these elements
alone will perceive that which is mediated by both of

4 them. The sense-organs are composed exclusively of these
two simple elements, air and water (for the pupil of the
eye is composed of water, the hearing of air, smell of
one or the other of these). Fire, however, belongs to no
organ or it is common to them all (for nothing is sentient
without heat). Earth belongs either to no organ or it is
chiefly and in a special manner combined with touch.
Nothing would remain, therefore, excepting air and water,

5 to constitute a sense-organ. Some animals have, in
actual fact, these organs as described. Animals which are
perfect and not defective have all these senses. For
even the mole, as one may observe, has eyes underneath
its skin. Consequently, unless there are bodies other
than those known to us, or qualities other than those
which belong to earthly bodies, we may conclude there
is no sense lacking in us.^

6 Neither is it possible that there should be any peculiar
organ for the perception of common properties such as
we perceive accidentally ^ by means of the individual

^ The argument here, that there can be no senses beyond the five
enumerated, is hopelessly obscure. The statement of the argument
is probably fragmentary. Bartht^lemy-St.-Hilaire [Traits de, VAme, p.
254, note) wrongly restates the argument, in his attempt to put an
intelligiljle meaning into it, and Zeller's rehabilitation of it (Eng. tr. vol.
I. p. 62) is not less obscure than the passage itself. The argument
apparently aimed to show that we are equipped with sense-organs to
cognize the qualities of all known bodies, and, as nature does not un-
necessarily duplicate these organs, they must be complete.

- Omit ou, which Bielil has incorporated into his text from Torstrik's
conjecture, against the better reading of all the mss. The emendation
entirely destroys the sense of the passage, it being the reiterated

HK. III. CHAP. I.

THK 'common SKNSIIILKS* 97

souses, I'jj. comnioii |)r()i)crties like iiiolion, rest, lorrn,
iiia^Miitiule, number, unity. For iill these properties
we perceive by means ol" motion, e.g. magnitude is per-
ceived by motion. So also is form, for form is a sort of
magnitude, and rest we ])ereeive from the absence of 7
motion. We j)erceive numbers by the negation of con-
tinuity anil by the special senses, for each sensation is
experienced as a unit. So, then, it is clearly impossible
that any particular sense should apply to these common
properties, such as motion. For this would be like one
now perceiving the sweet by means of sight. This is s
because we happen to have senses for both qualities {\i.e.
for the sweet and for colour]), whereby when the given
qualities coincide in one object, we recognize the object
as sweet.^ Otherwise we do not perceive the sweet,
excepting in the sense of accident, as e.g. when we
recognize the son of Cleon not because he is Cleon's son,
but because he is a fair object, which for the son of
Cleon is an accident.

We have indeed a 'common sense' for the perception of 9
common qualities. I do not mean accidentally. It is there-
fore not a particular sense, for in that case we should

doctrine of Aristotle that ' common properties ' are cognized by the
' seusus commimis,' in its own nature, and by the individual senses only
per accidens (De an. 425a 20, 25 ; 418a 9 ; 418a 24 ; De sensu, 437a 8).
Biehl seems to have been influenced by the ov Kara (xvfx^e^rjKos of
425a 28 and its apparent contradiction of the present passage. There
is, however, no contradiction, the ov /card, k.t.X. referring to the
function of the ' common sense,' while the Kara o-vfM^e^riKos refers to
the function of the individual sense.

^ We cognize the quality sweet by means of sight only per accidens.
We see a sweet thing e.g. when we see a grape with a given colour and
contour, knowing by experience that the colour and contour are
associated with a quality sweet to the taste.

G

98 Aristotle's psychology deanima

perceive in no other way than as just now described in

10 the illustration of Cleon. A sense, however, perceives
accidentally the qualities that are peculiar to a different
sense, not in their own nature but because of the
unity of these qualities, as when two sense-qualities

425 b apply to the same object, e.g. in the case of bile that it is
both bitter and yellow. Now, it is not the function of
either particular sense to say that both these qualities
inhere in one thing and it is owinG^ to this fact that error

o o

arises, when in the case of a yellow substance one opines
it to be bile. One might ask why we are endowed with

11 several senses and not with one only. Is it not that
facts of sequence and coincidence, such as motion, magni-
tude, and number, might the less escape us ? For if we
possessed sight only, and this were limited to the percep-
tion of whiteness, then all other distinctions would the
more easily escape our knowledge, and because colour
and magnitude are always coincident, they would appear
to be identical. In point of fact, however, since these
common qualities are found in different sense-objects, it is
evident that the several qualities themselves are different.

CHAPTEK II.

1>UT inasmuch as we perceive that we see and hear, we
must liave this consciousness of vision either by the
instrument of sight or by some other faculty.^ The
same faculty will then apply both to sight and to colour,
the object of sight. In this case, either we shall have two
senses for the same thing, or a sense will be conscious of
itself. Further, if there is another sense for the perception
of sight, either we shall have an infinite regre3sus, or
a given sense must finally be cognizant of itself, in
which case one would better admit this in the instance
of the original sense itself, i.e. sight. Here, however, is 2
a difficulty. For, if sensation by means of sight is vision,
and colour or that which possesses colour is what we see,
then the seeing faculty itself must first of all have colour
in order to be seen. It is plain, therefore, that sensation
by means of sight is not employed in a single meaning.
For even when we do not see, it is by means of sight
that we judge both of darkness and light, although not in
the same way. Furthermore, the seeing subject is in a

^ This function of consciousness is performed by the * sensus com-
munis.' Cf. Introduction, Chap. iv.

99

100 ARISTOTLE S PSYCHOLOGY de anima

3 certain sense saturated with colour, since each sentient
organ receives into itself the sensible object without its
matter. This explains the fact that when objects of
sense have been removed, the sensations and images still
persist in the sense-organ.

4 The actualization of the object of sense and of the
sense itself is one and the same process ; they are not,
however, identical with each other in their essential
nature.^ I mean, for instance, actual sound and actual
hearing are not the same. For it is possible for one
who has hearing not to hear, and for a sonorous body

5 not to emit sound at every instant. When, however,
that which has the potentiality of hearing and that
which has the potentiality of sounding, actually hear
and actually emit sound, at that moment the realized
hearing and the realized sound are simultaneously

426 a complete, and one would call them respectively the

6 sensation of hearing and the act of sounding. If,
then, movement, activity, and passivity are implied in
the produced object, it must be that actual sound
and hearing exist in a potential state. For creative and
motive activity is given in antecedent passivity.^ It
is, therefore, not necessary for the moving principle
to be itself in actual motion. For as action and
passion find their expression in the object acted upon
and not in the producing agent, so too the actualization
of the sensible object and the sense-organ is expressed

7 in the latter. The actualization of a sonorous body
is sound or sounding ; the actualization of the

' The one is the condition of the other.

^That is, in a potential condition or :v condition to be acted upon.

UK. III. CHAP. II. SKNSK-riHU^KrriON 101

hearing ort,'an is audition or hearing. For hearing in
twofold and sound is twofold, and the same statement
applies to other senses and sense-objects. In some
instances the two have a distinct name, as e.g. hearing s
and sounding ; in other instance's one of the two is
nameless. For the actualization of sight is called seeing,
but the actualization of colour has no name ; the actual-
ization of the organ of taste is called tasting, while the
actualization of tlavour is nameless. Inasmuch as 9
the actualization of the sense-object and the sense-organ
is one and the same process, although the two things
differ in their essential nature, it is necessary that
hearing and sound, in this sense, should be both either
destroyed together or preserved together ; and the same
applies to tlavour and taste, and to the other sense-
correlates. This necessity does not, however, apply to
the sense-correlates in their potential signification. On
the contrary, the old naturalists were wrong here,
supposing, as they did, that neither white nor black has
existence apart from sight, nor flavour apart from taste.^
In one way they were right and in another wrong. For lo
owing to the fact that sense and sense-object have a
twofold signification, namely that of potentiality and
that of actuality, their dictum was applicable to the one
meaning, but not to the other. They applied it, however, ^ i
to things absolutely which are not predicated absolutely.

^ By the old naturalists are probably meant Empedocles, Democritus,
and the Protagoreans (Philoponus Comment, ad 426a 22. Ed. Berl.
Ac. p. 475). Democritus distinguishes between the primary and
secondary qualities of things, referring the latter {e.g. colour, flavour,
etc.) to the perceiving agent, and the former [e.g. weight, density, etc.)
to the object. Cf. Theophrastus, De sensu, 63.

102 Aristotle's psychology deanima

If harmony is voice of a certain kind, and if voice
and hearing are in a sense one and the same, and in
another sense not one and the same, and if, further,

12 harmony is a relation of parts, hearing must likewise
be a relation of parts. It is for this reason {[i.e. because
sensation is a kind of proportion]) that every excessive
stimulus, whether acute or grave, disturbs hearing. In
like manner the sense of taste is disturbed by excessive

426 <^ flavours, the sense of sight by extremely glaring or
extremely faint colours, smell by excessive odours,

13 whether cloying or acrid. Consequently, qualities are
agreeable when, pure and unmixed, they are reduced to
proportion, as e.g. the pungent, sweet, or saline, or in
the domain of touch, the warm and cool. It is then
that properties are pleasant. In general, the mixed,
rather than the acute ^ or grave alone, is harmony. And
sensation is proportion. Excessive stimuli either produce
pain or pervert the organ.

14 Every sense is directed to its own peculiar sense-
object ; it is given in the sense-organ as such, and it
distinguishes the different qualities in its appointed
sense-object, as e.g. white and black in the case of sight,
sweet and bitter in the case of taste. And the same
can be said of other senses. Now inasmuch as we
distinguish white, sweet, and every sense-quality by its
relation to a particular sense, by what instrument do we

15 perceive that these qualities differ from one another? We
must do so by means of sensation, for they are sense-
qualities. Is it not plain that the flesh is not the final
organ of sense ? For the judging subject would then

^ Acute and grave are here used generically for extremes.

HK. Ml. . iivr. II. TIIK 'COMMON SKNSK 103

necoHSJirily diHtin^uisli an (»l)itH'-t l)y contaf.t. Neither iB
it pos.sible by ineariH of the (h.stiiict soriHeH to jml^e that
aweet is dillnreiit from while, Imt it is neccHsary that
both these (iiiJiliti(;.s be; cognized by some one j'aculty ;
otherwise it wouhl l)e like my perceiving one thing and
you anotluM', and so proving that tliey are different. A i6
single faculty must, therefore, say that they are different.
Kor the sweet is actually dilferent from the white. r)ne
and the same faculty, then, must alHrm this. And as
this faculty affirms, so do thought and perception agree.
It is clear that we cannot judge of distinct qualities by
different senses, and we can conclude from this that we
cannot judge of them at distinct intervals of time. For
it is one and the same principle in us which says that 17
the good is diftereut from the bad. Further, it says that
they are different and distinct at the moment when this
affirmation is made. And ivhen is not used here in an
accidental sense, by which I mean : ^vhen does not apply
merely to the time of the affirmation, e.tj. I say noiu that
it is different, but it applies also to the thing affirmed, I
say that it is different now, i.e. the time applies to the
assertion and thing coincidently. So the two elements 18
here are inseparable, and are given in an indivisible
moment of time. It is impossible for the same thing or
an indivisible entity to undergo opposite processes simul-
taneously and in an indivisible moment of time. For if
sweetness stimulates sensation or thought in one way,
then bitter stimulates it in an opposite way and white- 427 a
ness in some other way. Is, then, the judging principle^
something at once numerically indivisible and inseparable, 19

^ The j udging principle is the ' common sense. '

104 Aristotle's psychology deanima

yet separable in the mode of its existence ? There is a
sense, then, in which as divisible it perceives the divisible,
and a sense in which as indivisible it perceives the indi-
visible. For in its significant being it is divisible, but
spatially and numerically it is indivisible. Or is this

20 not possible ? Potentially, indeed, one and the same
indivisible thing may contain opposite properties, but not
in actuality ; in its realized self it is separate, and it is
impossible for a thing to be at the same moment both
black and white. So that it is not possible for even the
forms of experience to undergo these opposites, if sensation
and thought be such forms.^ Rather the case here is
similar to what some call a point, which is divisible or

21 indivisible, as one regards it in its single or dual nature.^
In so far as it is indivisible, the judging principle is one
and coincident with perception ; in so far as it is divisible,
it is not one, for it employs twice and simultaneously the
same mark. In so far as it employs a terminal mark as
two, it distinguishes two things, and these are separable
for it as a separable faculty.^ In so far as it regards
the point as one, it judges singly and coincidently with
perception.

In this way, then, let us state our definition of the
principle by virtue of which we say that animals are
sentient beings.

1 By the law of contradiction. Cf. Met. 10636 19 ; Cat. 126 10.

2 That is, as a single thing, or as the beginning of one line and the
end of another.

•'In so far as the mind looks at this single thing from two stand-
points, as beginning and end, it acts in a way distinct from perception ;
in so far as it looks at it as a single object, apart from relations, it coin-
cides with the act of perception.

CHAPTER TIL

Inasmuch as the soul is defined mainly by means of two
attributes, namely by locomotion on the one hand and
by thought, judgment, and sensation on the other, it is
supposed that thought and reflexion are a kind of
sensation (for in both instances the soul discriminates
and cognizes some reality), and even the old writers
tell us that reflexion and sensation are identical, as e.g.
Empedocles, who said : " Wisdom groweth in man in the
face of a present object " ; and in another verse : " Hence
is given unto them the power of reflecting ever and anon
on diverse things " ; and the words of Homer have the 2
same meaning : " Such is the mind." For all of these
ancient writers regard thought as something somatic, like
sensation, and believe that both in sensation and
thought like is apprehended by like, as we said in the
beginning of this treatise.^ They should at the same 3
time have spoken of error, for to animals this is more 427 <J
natural than truth, and their souls pass most of their
existence in error. According to this theory, as some 4
hold, either all phenomena must be true or else error

1 De. an. 4046 10 flf.
105

106 Aristotle's psychology deanima

consists in the contact of the unlike, for this is the
opinion that is opposed to the cognition of like by like.
Further, in this case error and knowledge of opposites
seem to be identical. That sensation and reflexion,
therefore, are not identical is evident. For all animals

5 share in the one, but few only in the other. Neither is
thought,-^ in which right and wrong are determined,
i.e. right in the sense of practical judgment, scientific

/ knowledge, and true opinion, and wrong in the sense of
the opposite of these, — thought in this signification is
not identical with sensation. For sensation when
applied to its own peculiar objects is always true, and
is inherent in all animals; but it is possible for discursive
thought to be false, and it is found in no animal which
is not also endowed with reason. Imagination, too, is
different from sensation and discursive thought. At the
/ same time, it is true that imagination is impossible without
sensation, and conceptual thought, in turn, is impossible

6 without imagination. That thought and conception, how-
ever, are not one and the same is evident. For imagina-
tion is under our control, and can be stimulated when we
wish (for it is possible to call up before our eyes an
imaginary object, as one employs images in the art of
mnemonics). Conception, on the other hand, is not

7 under our control. For it must be either false or true.
Furthermore, when we conceive that something is terrible

' Noerv is used here as genus, of which <pp6vr]<ni, iinaTijiin], and
o6^a dXrjdrjs are species. Thought is called (pp6vT)(TL<i {prudence) when
directed to a practical end, iiriaTT^fMrj {scientific knowledge) when it is
theoretical and the conclusion is demonstrable, du^a iXrjdrjs {right
opinion) when the conclusion is not reached by scientific procedure or
is not demonstrable and yet is true.

UK. III. riiM-. III. IMACINATION 107

or rcarriil, we liiiv(; at once* a correspondirjj^ icelin^', and
the saint' may l)(; Haid of what inspires courago. lint in
the case of iniaj^ination we. arc in the .same condition as
if we wore to pliice a terrible or a courage-inspiring
object before us in a picture. In conception itself tliere
aiv distinct forms, such as knowledge, opinion, reflexion,
and their opposites, concerning whose different meanings
we shall speak later.

Since thinking difi'ers from sense-perception, and in s
one signification appears to be imagination and in another
signification conception, we must proceed to the treat-
ment of the latter, after we have defined imagination. 9
If imagination means the power whereby what we call a 428 a
phantasm is awakened in us, and if our use of language
here is not merely metaphorical, then imagination is one
of those faculties or mental forces in us by virtue of which
we judge and are capable of truth and error. And these
faculties include sensation, opinion, scientific knowledge,
and reasoning. That imagination is not to be con-
founded with sense-perception is plain from the following lo
considerations. Sensation is either a mere power or a
distinct act, like sight and seeing, but imagination is
present when neither of these conditions is realized, viz.
in the phantasms of dreams. Again, sensation is always
present, but this is not true of imagination. If in reality
it were identical with sensation, then all animals would
have imagination. This does not seem to be the fact, as
we find in the case of the ant, the bee, and the worm.
Again, sensations are always true, while imaginations are u
for the most part false. In the next place, we do not
say when we are accurately observing a sense-object, that

108 Aristotle's psychology deanima

we imagine it to be a man. We say this rather when we

12 do not clearly perceive [and when the perception may
be true or false], and as we said above, we see imaginary
pictures even when our eyes are closed. But neither is
imagination one of those faculties whose deliverances are
always true, as e.g. scientific knowledge and reason.
For imagination can also be false. It remains to be
considered whether it is opinion, for opinion can be either

13 true or false. Opinion, however, is followed by belief (for
no man can have an opinion and not believe what he
opines), and none of the lower animals possesses belief,
although imagination is found in many of them. [Again,
every opinion is followed by belief, as belief is followed
by persuasion, and persuasion by reason. Now, some of
the lower animals have imagination, but none of them

14 have reason.] It is plain, then, that imagination is not
opinion combined with sensation, nor mediated by sensa-
tion, nor a complex of opinion and sensation, and, for
the same reason, it is clear that opinion has for its
object nothing else than what sensation has for its object.
I mean e.g. that imagination is the complex of an opinion
of whiteness and a sensation of whiteness, and not the
complex of an opimon of goodness and a sensation of

428 <^ whiteness. To imagine, therefore, is to opine what,

15 strictly regarded, is a sense-object. Again, there are
false appearances when we have correct conceptions, as,
e.g. in the case of the sun which appears to be a foot in
diameter, whereas we believe it to be larger than the
inhabited earth. The consequence is that we must either
have thrown aside our true opinion which we held,
without the thing having changed and without any for-

MK. III. ( IIAI-. III. IMACMNATION AND TKUTII lOli

getfulnoss or chaii^o of oonvictioii on our purl : or if otim
still holds it, it is ncccHHary that the Htiiiie oi)inion be both
true and false. lUit an ()i)inion has lu'conie false in a i6
case where an object, without our knowing it, has
changed. Iniaijinalion, then, is not one of these faculties 17
nor a derivative of them.

Since one thin<^' when moved can communicate motion
to another, luul since imagination is held to be a form of
motion which does not come into existence without
sense-perception, but only in sentient creatures or in
reference to objects to which sensation applies, and since
motion is produced by the action of sense-perception, and
this motion must be equal to the strength of the sensa-
tion, one can affirm that the motion of imagination
would never be possible without sensation nor could it
take place in non-sentient creatures. Further, the one
who experiences it can act and be acted upon in many
ways, and one's experiences may be true or false. This 18
truth or falsehood is due to the following causes. Sense-
perception is true when it concerns its own peculiar
objects; at any rate, there is involved in this case, the
least possible amount of error. In the second place, sense-
perception may concern the accidental, and here error
begins to be possible. One is not mistaken in saying that
a thing is white, but if one says the white object is this
or that particular thing, error arises. In the third place, 19
error applies to common properties and concomitants of
the accidental, in which peculiar properties are involved.
I mean e.g. motion and magnitude, which are accidental
properties of sensible objects, and concerning which we
are especially liable to error in sense-perception. The

110 Aristotle's psychology deanima

motion set up by the activity of sensation will differ in

20 terms of the three following forms of sense-perception.
The first movement is when the sense-perception continues
present, and this is true ; the other two may be false
whether the object is present or withdrawn, but are
especially liable to error when the sense-object is
removed.

If imagination contains nothing but the elements

429 a named and is what we have described it to be, it would

be a movement stimulated by actualized sense-perception.

21 Since sight is our principal sense, imagination ^ has

^ The words (pavraaia and (pdos are derived from cognate roots {(pav
and (paF) and (paiueadat and (pavTaaia are etymologically akin. Aristotle's
statement that the one is derived from the other is not strictly correct.
It has been shown that imagination is not atadrjais (sensation), nor vovs
(reason), nor iTnaT-qfii) (scientific knowledge), nor Bb^a (opinion). It
originates, however, in the ■sen-'^us communis and is a movement set up
there by a past sensation. A sensation when past may leave an after-
eflFect in the sense-organ which again, unless some greater or cross -
stimulus inhibits it, may pass to the heart (the organ of the 'commor
sense ') and there be revived as a pictorial image or phantasm, the real
object being no longer present. This revival of a sense-image is
imagination or phantasy ((pavraaia), and the image thus reproduced is a
phantasm {^duraa/jLa). Sensation, therefore, is a prerequisite of im-
agination, although the revival of the residual image of sense is
emancipated from the action of the sense-organ itself. Aristotle dis-
tinguishes imagination from sensation : (1) imagination is a function of
the internal or ' common sense ' {De mem. 450a 10), sensation is a
process of the external sense ; (2) imagination may be active in sleep, when
the senses are inactive, or when the eye is closed one may have visual
imagination (428a 16) ; (3) sensations, as such, are true, while imagina-
tions are in large part false ; (4) sensation is possessed by all animals,
imagination by certain ones only (428a 10). Again, imagination is
distinct from reason (vovs) and scientific knowledge (eVKmy/iT;), for (1)
both the latter proceed by necessary steps and are consequently true,
while imagination is sometimes true and sometimes false (428a 18) ; (2)
the steps in rational or scientific knowledge are not in our control, they
follow from inherent necessity, while the pictures of imagination are
arbitrary (427/' 18). Further, imagination is distinct from opinion

iiK. III. <iiAi. 111. I.\IA(JINA'I'I<)N AND LU'.WV 111

derived it.s iiaiiK; from li^^ht, lH»cauHO si;^'lii is iinposHible
without li^ht. I)(^cause inia^(;H ])orMiHt and r('.s(»iiible
sense-perccptioiiH, animals re^ulato tlnjir actions to a large
degree by imagination, some of them because they are
incapable of reason, as the lower brutes, others because
reason is sometimes veiled by passion, disease, or sleep, as
is the case amongst men. (.Concerning imagination, what its
nature is and what end it subserves, let the foregoing suffice.

(56ta) : (I) opinion is accompanied by belief, which is not true of
imagination ; (2) we may have a correct opinion about a thing, but our
imagination about the same thing may be quite at variance with the
opinion {4'2Sh 2). Further, it is not a combination of opinion and
sensation as held by Plato (Soph. 2G4i5, avfifxi^is aicrdrjaews Kai oo^-qs),
because opinion and imagination may contradict, and consequently, in
this case, must exclude, each other.

When the image is recognized as that of an object perceived in the
past, with a consciousness of time, the imagination is then termed
memory {ixv-qix-q) and the image is jxirqjxbvevixa. If the reproduction of
the image is conscious and deliberate, the act is recollection [dvd^ivqais).
Inasmuch as the latter act requires reflection, only man is endowed
with it, although memory is shared by the brutes [De mem. 453a 6 fi).

There is another form of imagination which one may call the general-
izing imagination, and which Aristotle regards as the source of the
images that accompany conceptual thought. He says there is no
thought without an image (403a 8, 431a 16). As sensation is to the
imagination, so is the imagination to thought (431a 14). Residual
images are, therefore, the intermediary links between sensation or
sense-perception and thought. Regarded as after-sensation, imagina-
tion is called (pavraaia aiad-qTiK-q ; regarded as the prerequisite of
thought, it is called pavraaia XoyLCTLK-q (4336 29). Imagination is a
weak or spent sensation {atadt)(TL^ dcdevrjs, Rhet. 1370a 28) or in Hobbes'
language a "decayed sensation." Cf. Freudenthal, Ueber den Begriff
des Wortes (f>avTa(Tla p. 24.

The imagination in its reproductive function is the source of memory,
recollection, and the association of ideas ; in its productive or con-
structive function, it is the origin of fancies and distorted pictures in
dreams, fever, and melancholia. Without it language would be im-
possible (4206 32), and it gives clearness to conceptual thought by
clothing this in the schemata of sense (427a 16 ; 4316 4 ; 432a 9).

CHAPTEK IV.

Regarding that part of the soul by virtue of which one
knows and reflects, whether it be a distinct part or
whether it be distinct only notionally and not really, we
have now to consider what its differential mark is, and by
what process thinking is exercised. If thinking is like
sense-perception, it would be either a kind of impression
made by the object of cognition or some analogous

2 process. It must, then, be impassive and yet receptive
of the form,^ and in its nature potentially like to the
object of thought without being this object ; and as the
sense-organ is related to the object of sense, in a similar

3 way thought must be related to the object of thought.
Eeason must, therefore, be unmixed, as Anaxagoras says,
since it thinks everything, in order that it may rule, i.e.
in order that it may know.^ It is the nature of thought

^ Sensation is described by Aristotle as the receptivity of the form
or idea of a sensible thing without its matter {De an. ii. 12, 424a 18,
deKTiKdy tCjv ala6r]Tu)u eidwy &pev ttjs vXrjs).

'^This interpretation of Anaxagoras is regarded by Burnet (Early
Greek Philos. p. 28.3 fr. 6 and 293, note) as unhistorical. He thinks
the power of Nous to * rule ' means only the power to move and direct
{Kv^epudv). Aristotle himself gives precisely Burnet's interpretation
of the Anaxagorean Nous in Fhys. 2566 25 {KLvqocws dpxv*' > Plato,

112

i.K. III. en. IV. TirKOKV OK KKASON 1 1 .'i

to j)roc;lu(le and reHtniiii the ehiinoiit that is foreign and
adjacently seen. Its nature is, therefore, exchisively 4
potentiality. What we call reason in the soul (by reason
I moan the instrument by which the soul thinks and forms
conceptions) is, prior to the exorcise of thought, no reality
at all. It is, therefore, wrong to suppose that reason itself
is mixed with the body. For in that case it would have
certain qualitative distinctions such as warm or cold, or
it would be a sort of instrument, like a sense-organ. P>ut
in point of fact it is nothing of the kind. Certain writers^ 5
have happily called the soul the place of ideas, only this
description does not apply to the soul as a whole, but
merely to the power of thought, and it applies to ideas
only in the sense of potentiality, and not of actuality."

Gratyhui^ 413c), and according to De an. 4056 22 and 4296 23, he
would seem to have been unable to find any epistemological use for
this Nous. The interpretation of Aristotle in the passage before
us can, however, very well be a correct deduction from the principle
of Anaxagoras, viz. that in order to rule and arrange all things best,
the reason must also know all things, and it is not unlikely that
Anaxagoras even made explicit mention of this ; it is certainly
implied in the fragments. " Nous is the subtlest of all things and
the purest [i.e. the least mixed], and it knows all and has all
power " (fr. 123, Burnet p. 2S3). By virtue of its subtle nature, and
its being unmixed with the elements (I am not concerned here with the
moot question of its incorporeality), the Nous is able to penetrate
everywhere, and so has the most far-seeing knowledge as well as most
wide-reaching power. Nous must then be unmixed and pure to be
almighty and all-knowing, and consequently the commentary of Aris-
totle seems a legitimate construction to put upon Anaxagoras (cf.
Zeller, Phil. d. Gr. Vol. I. 4th ed. p. 887 ; Trendelenburg, De an. 2nd
ed. p. 385). In fact, it was precisely the element of knowing that was
the important factor in the Anaxagorean Nous, as Orderer of the All.
^ Plato and the Academy.

* Potentially, reason is that which becomes thought (there are no
innate ideas) ; but the actual reason is identical with the actual
thought, and in thinking its ideas the reason thinks itself (4296 9).

H

114 Aristotle's psychology deanima

It is evident from the sense-organ and from the nature
of sensation, that the term impassivity is employed in a

6 different meaning in sensation and in thinking. For
sense-perception cannot take place when the sense-

429 <J stimulus is excessive, as one does not hear sound in the
midst of loud noises, neither can one see nor smell in the
midst of excessively bright colours and strong odours. On
the other hand, when the mind thinks a very profound
thought, it thinks not in a lesser but in a deeper
degree minor details. For the power of sensation is not
independent of the body, while the mind is separable.

7 When reason becomes its several objects in the sense in
which an actually learned man is said to be learned (and
this takes place when he can exercise knowledge through
his own agency), even then reason is in a certain sense
potential, although this potentiality differs from that
which preceded learning and discovery. In the latter

8 case, potentiality signifies the capacity of thinking itself

There is a difference between concrete magnitude
and the ultimate nature of magnitude, between water
and the ultimate nature of water (the same distinction
can be applied to other instances, though not to all,
for in some cases they are identical). Concrete flesh
and the ultimate nature of flesh one judges either by
a different and distinct faculty or by the same faculty
under differing conditions. Flesh is not separate from

9 matter, but like a snub-nose, it is a particular thing
in a given something. By means of a sense-organ one
discriminates heat and cold and those qualities of which
flesh is a sort of register. On the other hand, reason
judges of the essential nature of flesh either by a

HK. 111. ni. IV. ARSTRACrr TllOUf JHT 1 1 T)

iliflrreiit Jind distinct faculty, or in the way in which
a bent lin(^ is related to itself when straightened.'
We refer the straip^ht line as we do the snub-nose to
abstract entities,* for they are both associated with the
continuous. Hut the essential notion of a tiling, if
straightness and the straight line are different (and they
are two things), is apprehended by a different power.
The mind, then, judges in the two cases by means of
a different power or by means of a power differently lo
conditioned. In a word, therefore, as there are things
abstracted from matter, so there are things that concern
the reason. If the mind is simple and impassive, and
has nothing in common with anything else, as Anax-
agoras ^ says, and if thinking means to be somehow 1 1

^ The bent line represents the concrete, distorted things of sense
and the straight line the pure notion, and the two things correspond,
apparently, to the distinction made above between to aapKi ehai and
ffdp^, etc. Cf. Kirchmann and Wallace ad loc. Teichmiiller's explana-
tion (quoted by Wallace) of the bent line as reprcserting reason,
although ingenious, is not helpful here.

^ These conceptions belong to mathematical notions and figures, and
are abstract when contrasted with a material thing, but concrete when
contrasted with the essential notion. Mathematical ideas (including
' snub-nose ' as a figure) occupy a middle place in their degree of
abstraction between the pure notion and a sense-object. The mathe-
matical and the sense-object both belong to the continuous or the
extended in space (fxera <xvvexovs). Cf. Phys. 194a 10 ; De an. 4316 15.
Mathematical entities are separable from matter only in logical con-
ception. Metaph. 1026a 7 fi". ; 1061a 28 flf.

^ Anaxagoras gave no detailed account (as far as the fragments go)
of the way in which we get our ideas of things, beyond the state-
ment that the senses are too weak to discover the ultimate nature of
reality, and that we know the existence of the 6/ioto/xepeiat (as his
successors called the original homogeneous seeds or particles of things)
only by processes of reason. This latter by its subtle and pure nature
is capable of penetrating everywhere {vid. note 2, p. 112) and making
the finest distinctions. In his theoiy of sensation Anaxagoras says we

116 Aristotle's psychology deanima

impressed, one might ask, How will thought be possible ?
For it is only in so far as there is something common
to two things that the one appears to act and the
other to be acted upon. A further question might
be raised, viz. whether the mind itself is the object of
thought. If it is, mind will then either be found in
other things, unless it is the object of thought in some
way different from other objects, and unless the object
of thought is a specific and single thing ; else it will
have a mixed composition which makes it like other

12 things, the object of thought. According to our former
definition, * to be affected in reference to a common
element,' means that the mind is potentially the object of
thought, though perhaps not actually so until thought takes
place. It must be that the case here is similar to that

430 « of the tablet on which nothing has been actually written.
This is what takes place in the case of mind, and it is

13 the object of thought as other things are. Where entities
are without matter, the subject and object of thought
are identical. Speculative thought and the thing specu-
latively known are one and the same. The reason why
thought is not continuous must be investigated. On
the other hand, when entities are material they are
severally the object of thought only potentially ; mind
is not an element in them (for reason is the potentiality
of such objects in abstraction from their matter), whereas
it is in the reason itself that the object of thought will
be found.

do not apprehend like by like (Empedocles), but unlike by unlike, cr/.
heat by cold, etc. Cf. Zeller Phil. d. Or. Vol. I. 4th ed. p. 908.

CHArTER V.

In the whole of nature there is on the one hand a
material factor ^ for every kind of thing (and this is
what all things are in their potentiality), and another
factor which is causative and productive of things, by
virtue of its making all objects, as art stands related to A^*^^'
the matter it employs. These distinctions must also
hold good when applied to the soul. Reason is of such 2
character that on the one hand it becomes all things,
and on the other creates all things, in this respect
resembling a property like light. For light in a certain
sense converts potential into actual colours, and reason, in
the present meaning, is separate, impassive, and unmixed,
being in its essential nature an energizing force. Now,
action is always higher than passion and causal force
higher than matter. Actual knowledge is identical 3
with its object. Potential knowledge, on the other hand,
pre-exists in the individual ; regarded absolutely it does

^ * Material factor ' does not necessarily mean a thing constituted of
crass matter, but refers to the metaphysical distinction between * form •
and 'matter,' which in other terms are ' actuality' and 'potentiality.'
In this meaning sensations as containing the potentiality of ideas are
their 'matter.'

117

118 Aristotle's psychology deanima

not so pre-exist. For mind does not at one moment
think and at another not. In its separated state alone
reason is what it is, immortal and eternal. We have no
memory of it, because this part of reason is impassive.
The passive reason, on the other hand, is perishable,
and without it there can be no thought.^

"^ Vid. Introduction, Chap, viii., and The Classical Review, Vol. VI.
(1892), pp. 298 ff.

CHAPTEPt VI.

When thoii<]jht is applied to indivisible terms, error does
not arise. Where error and truth are both found is just
in the combination of thoughts into a sort of unity.
Empedocles^ e.g. says; "Wherefore the heads of many
creatures sprang into life without necks," and later on
by the attraction of Friendship they were joined to-
gether. So, too, these disjoined ideas are combined 2
together by the reason, as e.g. the ideas of the incom-
mensurable and the diagonal. If the ideas refer to the
past or to the future, the element of time is added in 430*^
the mind and combined with the ideas. Error is always
due to the combination. For even in the case where one
might think the white not to be white, one has made
the combination of the ' not-white.' ^ It is further
possible to apply disjunction to everything. It is not 3
only possible for the statement ' Cleon is fair ' to be
true or false, but this may be applied to the past or to
the future. The unifying principle is in every case the

1 Burnet, Early Greek PhUosophj/, pp. 226, 229. Ritter and Preller
Hist. Phil. Gr. p 140a.

'■^Omit (^Kai) (XevKovy which Biehl adopts from Cod. T and Roper's
conjecture against the better reading of all the other Codd.

119

120 Aristotle's psychology deanima

reason.^ Since the simple or indivisible may be looked
at from two standpoints, viz. either as potentiality or as
actuality, there is nothing to prevent the mind from
thinking the indivisible when it thinks of extension
(which in its actual state is indivisible), and when it
thinks it in an indivisible moment of time. For
divisibility and indivisibility apply to time just as they

4 do to length. It is, therefore, impossible to say what
the mind thinks in each half of a time-division.
For the half does not exist, except in potentiality, if
the division has not been made. But in the act of
thinking each half separately, the mind divides the
time also, and then the time corresponds in its division
to the two lengths.^ If, however, the mind thinks
the object as a whole composed of two halves, it does
this also with regard to time in its relation to the

5 two halves.

That which is not quantitatively but only notionally
indivisible, the mind thinks in an indivisible time and
by an indivisible power of the soul. It does this, how-
ever, accidentally and not in so far as the factors of
thought and time are divisible, but in so far as they
are indivisible. And there is also in these cases an
objective factor which is indivisible, although perhaps not

6 a separate entity, that gives a unity to time and exten-
sion. And this is likewise true of everything that is
continuous, whether in time or space. The point and
everything obtained by division, and whatever (like a
point) is no longer divisible, are explicable in terms of

' The principle that combines or unifies terms into judgments.
^ And the single length is then a unit and no longer a half.

UK. III. < II. VI. THOIKIHT AND TIUITM 121

privation.' Similjir reasoning' iniiy he applicid to other
cases, as e.g, the way in which we know evil or hlaek.
For we know them somehow or other hy means of their
contraries. Hut the knowing mind must be these things
potentially, and they must be reduced to unity in the
mind itself. If, however, in the case of any causal 7
principle there is no opposite, then it knows itself, and
is in actuality and is separate. A predication, as e.g.
an affirmation, asserts something of something else, and
is in every instance either true or false. This does not
apply to the mind always, but when the mind asserts
what a thing is in its essential nature and not what
attaches to something as a predicate, then it is true.
And just as sight is true when it concerns its own proper
object, and on the other hand the opinion that a
visible white object is or is not a man may not always
be true, so it is with all immaterial entities.

^ As privation of extension.

CHAPTER VII.

431a Actual knowledge is identical with its object. Potential
knowledge is earlier in time in the individual, but taken
absolutely it is not earlier in time. For all becoming
proceeds from actual being. The sensible object appears
to convert the potentially sensitive organ into an actually
sensitive organ. For the sense-organ itself is not affected,
and undergoes no change. That is the reason why we
2 have here to do with a form of motion different from
motion in the ordinary sense. Motion was defined as a
realization of the incomplete, but motion, absolutely
regarded, is a different kind of activity, viz. the activity
of the perfected thing. Mere sense-perception, then, is
like a simple expression or a simple thought ; when,
however, the sensation is pleasant ^ or painful, and thus
corresponds to affirmation or negation, the thing is
pursued or avoided. To feel pleasure or pain signifies
to experience an activity in a mean function of the
sense-orcjan relative to orood or bad as such. Avoidance

1 When the simple term or thought is converted into a judgment, it
takes the form (intellectually) of affirmation or negation, and the form
(in practice) of doing or avoiding. In the one case we have truth or
error, and in the other right or wrong.

122

HK. 111. (Ml. VII. TIIOUCJHT AND 1MA(JKS 123

and pursuit in thoir Jictual natures aro identical, and the 3
apj)etitivo j)ow(M- wlu^rcby vvi; dosirc or pursue a thin^ is
not difVerent iVoni the power whereby we avoid a thin^'.
They do not diller Iroui (muIi other or from the sensitive
faculty. Only the expression of their being is different.
Images are employed by the concej)tual reason as sense-
presentations arc by the sentient faculty. When the
mind makes an affirmation or negation touching the good
or bad, it avoids the one and pursues the other. The
soul, therefore, never thinks without the use of images. 4
As the air produces such or such an effect on the pupil
of the eye, and the pupil in turn produces another effect
(the same illustration may be applied to hearing), and
yet the ultimate interpreter or medium of sensation is a
single power whose being is expressed in several ways,
([so it is with images^ in reference to thought.]) As to
the faculty by which we discriminate sweet and warm,
although the problem has been mentioned above, it
must be again discussed as follows. There is some
unitary principle, and this unitary principle has the 5
character of an ultimate term. Its deliverances are
reduced to unity by means of comparison and numerical
statement, and are related to each other as the outward
things are related to each other. The question as to
how the mind judges like qualities, does not differ from
the question as to how it judges opposite qualities such

^ As the air is a condition of sensation, so are images conditions of
thought. The illustration is not a very happy one, but the meaning
appears to be that as there is an unitary principle of sense which
elaborates its varied materials into a whole, so there is an unitary
principle of thought which reduces these images (ultimately drawn
fi'om sense) to the form of connected concepts.

124 Aristotle's psychology deanima

6 as white and black. Let A, the objectively white, be
related to B, the objectively black, as the idea C is
related to the idea D, or it may be stated conversely.
Now, if the ideas CD attach to a certain thing, they will
be related to each other ([in the concept]) just as AB are
related to each other, — they will form one and the same
thing, though not identical in mode of being ; and the
former combination (CD) is analogous to the latter
(AB) ^. The same reasoning holds in case one were

431 d to apply A to a sweet object, and B to a white

7 object.

The reasoning mind thinks its ideas in the form of
images; and as the mind determines the objects it should
pursue or avoid in terms of these images, even in the
absence of sensation, so it is stimulated to action when
occupied with them. For example, when one sees that a
beacon is lighted, and observes by means of the ' common
sense ' that it is in motion,'^ one comprehends that an

8 enemy is near. Sometimes by means of the images or
ideas in the soul the mind reasons as a seeing person,
and takes thought for the future in terms of things before
one's eyes. When the mind there in its world of images
says that a thing is pleasant or painful, here in the world
of things it pursues or avoids, — in a word, it acts.
Apart from action the true and false belong to the same
category as the good and bad. They differ, however, in

^ The illustration appears to mean that just as qualities are
combined in a given thing and form an unitary object, so subjectively
they form a single and unitary concept. They are identical in signifi-
cance, though different in their mode of being.

2 Motion is one of the koivo. aiadrjra and as such is not discerned by
any individual sense but only by the * common sense.'

liK.iii. (Ml. VII. Tiroudirr and its ohjkct 125

the ubsoluto chanic.tcir ol" the one and tlie relative
character of the other.'

The mind thinks abHtractions, as c.y. when it thinks 9
the snub-nosed, which in one sense is a snub-nose, atid in
another sense, if one thinks it actually, one would think
it as a curvature without the flesh in which the curvature 10
is found. So too with mathematical figures, though in
actuality not separate from bodies, the mind thinks them
as separated, when it thinks them. In a word the mind
is the thing when actually thinking it.~ Whether or
not it is possible to think any abstraction when the mind
itself is not separate from magnitude, must be investi-
gated later.

^ The true and false are universally valid, regarded merely from the
standpoint of cognition, but when regarded in the light of wrong and
right they are relative to the individual. Or the passage may have
another significance, viz. the notions of good and bad affect our wills and
stimulate to action only when they are referred to particular objects.
Vid. Kirchmann, p. 183.

^ In the act of thinking, subject and object are identical ; the think-
ing mind is the idea thought.

CHAPTER VIII.

Looking at the main features of what has been said of
the soul, let us reiterate the statement that it is in a
sense all reality. For everything, whether sensible or
intelligible, is psychical ; intelligible objects are in a
sense knowledge, and sensible realities are sensations.
How this is possible remains to be investigated. Con-

2 ceptual knowledge and sense-perception are each divided
into two kinds, corresponding to their objects ; potential
knowledge corresponding to potential objects, and actual
to actual. The sensitive and conceptual powers of the
soul are, potentially regarded, the objective things, viz.
the intelligible and the sensible. The soul, then, must be

3 either the things themselves or their form. It cannot, of
course, be the things themselves. For a stone is not in
the soul, but the form or idea of the stone. Consequently,

432 fl the soul is to be thought of as a hand; for a hand^ is the
instrument of all instruments, and the reason is the form
of all forms and sensation in the form of all sensible

4 realities. Since, however, there is no object, as is supposed,

^ As the hand is the master instrument, so the soul is the master
interpreter and reduces all things to a significant form.

126

jiK.ni. (11. VIII. IDKAS AND IMA(iKS 127

apart from acjnsihlo ina«^nitmles,' it follows tliat iiitclli-
j^ible objects, — I uunm abstractions, a.s we call them, on the
one hand, and the qualities and condition.s oi* the scnsible.s,
on the other, — must be sought in the sense-forms. For 5
this reason, also, it would be inj])ossible for one to learn
anything or understand anything without sense- perception,
and when one contemplates a thing, one is forced to con-
template it in conjunction with an internal image. These
images are like sense-presentations, with the exception that
they are without matter. Imagination is different from 6
aftirmation and negation ; for the true and the false are the
combination of ideas into a judgment.^ In what way are
the primary ideas ^ to be distinguished from imagination ?
Or is it true that these * ideas are not themselves
images, yet they cannot be produced independently of
images ?

* The world of magnitudes and objects in space are mediated to the
imagination by means of sense-presentations (alad-^/xaTa), and to thought
by means of sense-representations or images {(pavrdafiaTa).

^Images {(pavrda/xaTa) of the productive imagination, although they
may correspond to no reality, yet are not, strictly speaking, either true
or false. Truth and falsehood belong only to judgments or to an image
when something is predicated of it.

•* The primary ideas {irpOra vo-fifxara) refer to our highest abstractions.
Although these notions are not (pavrda-fiaTa, their derivation is dependent
on such images.

4 Read ravra (Torstrik) instead of riWa.

CHAPTEK IX.

Since the soul of living beings is defined in terms of two
powers, viz. the power of judgment (which is the function
of thought) and the power of sensation on the one hand,
and the power of locomotion on the other, let the above
suffice for our treatment of sensation and thought, and
let us now consider the moving principle and ask what
part of the soul it may be. The further question arises
whether it is an individual part of the soul and separate,
either concretely or notionally, or whether it is the
entire soul. If it is only a part, we must ask whether
it is a peculiar part and distinct from those usually
described and already mentioned here, or whether it is

2 one of these. There is a difficulty at the start con-
cerning the sense in which we are to employ the term

3 ' parts ' of the soul, and concerning their number. For
in a certain way they seem to be innumerable, and not
merely confined to those which certain writers distin-
guish, viz. reason, will, and desire,^ and others classify
as rational and irrational elements. For according to
the differences by which they distinguish these parts,

' riato, liejmhlic 441a (XoyLariKdy, dv/xoeid^s, ixidvp.r)riK6v).

128

i.K. MI. (II. i\. J'OWKRS OK 'rirr, soul 120

ihcro iSc.ciu L(» l»ci oilier parts that aro t;ven nioTv. distinct
from each othrr tliaii these, concerniii{^ which we liave
just now spoken, viz. tlie nutritive part, wliich i.s found
even in phints as well as in all animals, and the sensitive
part, which one could not easily classify either as irrational
or as rational. Aj.;aiu, the power of imagination, which is 4
different in its mode of being from the others, appears to 432'''
be a distinct part, but in what particular it is identical with
or dillerent from the others, is very difficult to say, if one
is to regard the parts of the soul as existing inde-
pendently of one another. In addition to these, there is
the desiderative part, which both notionally and function-
ally might be supposed to differ from all the other
parts. And yet it would be absurd to sever this from 5
the others. For it is in the thinking element that
volition arises, and in the irrational element we have
desire and passion. But if the soul has three distinct
parts, then the desiderative element must be in all of
them. Moreover, the question again comes up which we 6
raised just now, viz. what is the principle in animals
that produces locomotion ? One might suppose that it
is the generative and nutritive powers, found in all
living things, that produce the motion involved in growth
and decay common to them all. The subjects of inspira-
tion and expiration, sleeping and waking, must be
investigated later, for all of them present great difficulties.
But regarding locomotion, we must inquire what it is 7
that gives animals the power of progressive movement.
It is evidently not the nutritive power, for progressive
movement is always towards some end and accompanied
either by some image or desire. For where there is no

130 Aristotle's psychology deanima

8 desire or revulsion, there is no motion, excepting where
external force is used. Further, if motion were due to
the nutritive power, plants would be capable of loco-
motion and would have some organic member adapted to
this motion. Soo, too, it cannot be the sensitive power
that is the source of motion ; for there are many animals
which have sensation and yet, throughout their existence,

9 are stationary and motionless. If, then, nature creates
nothing in vain, neither does she omit anything that is
necessary, save in cases of deformed or imperfect beings.
And such animals as we have in mind are normal and not
deformed. A test of perfection is the capacity to
reproduce, to reach the prime of growth, and then decline.
Consequently, such animals should also have organs of
movement.^

10 But neither is the thinking power nor what we call
reason the cause of animal motion. For the contempla-
tive power does not think upon what is to be carried
into execution, neither has it anything to say touching
what is to be avoided or pursued, whereas motion always
belongs to that which pursues or avoids an object. On

11 the contrary, when one contemplates anything, the mind
does not bid one pursue or avoid ; e.g. the fearful or
pleasant is often the subject of thought, but the feeling of
fear is not suggested ; the heart, however, is agitated, or
if the feeling is pleasure, some other organ is stirred.

433 a More than this, even when the reason commands and
intelligence tells us to avoid or to pursue a thing, motion

^ If locomotion were a function of the sensitive soul, these animals
that are endowed with sensation, and are normal, would not be
stationary, as some of them are (cf. note 1, p. 171), but would move.

UK. III. (Ml. IX. KKASON AND DKSIKK 1 .11

doos not follow, hut onn acts according to one's desire,
liki; an iiitonipt'nitt' man. We observe, in general, that 12
the man versed in nicdicinc^ docs not lical, hecause it is
something other than Hcience that has the power of
acting according to the ])rinci|)los of science.^ Neither,
again, is desire the dominating ])rincij)le''^ in this motion;
for continent men, though filled with desire and ai)petite,
do not do the things for which they lust ; on the con-
trary, they follow reason.

' It ia not science, but nature, the principles and laws of whose
operation are formulated by science, that heals.

- Neither desire nor reason taken alone is the principle of action in
men, but the combination of these two. Cf. 4'A3a 23.

CHAPTER X.

There are two powers in the soul which appear to be
moving forces — desire and reason, if one classifies imagina-
tion as a kind of reason. For many creatures follow
their imaginations contrary to rational knowledge, and in
animals other than man it is not thought nor rational
procedure that determines action, but imagination. Conse-

2 quently, both of these, reason and desire, can produce
locomotion — I mean here the reason that considers ends
and is concerned with conduct.^ It differs from the
theoretical reason in having a moral end. Every desire

3 aims at something. It is the final end that is the initial
cause in conduct.^ So that it is reasonable to regard
these two principles, viz. desire and practical reason, as
motor forces. For the object of desire stimulates us, and
through it reason stimulates us, because the object of
desire is the main thing in the practical reason. Imagina-
tion, too, when it stimulates us to action, does not do so
independently of desire. The one single moving force is

^ This is the epitactic reason {(Ppdvrjcris iirLTaKTiKr)) of the Ethics
{Eth. nic. vi. 10, 2). The theoretical reason deals with necessary truth,
while the practical or epitactic reason deals with the contingent or
what is matter of choice.

' The end of action is motive or starting-point.

1.S2

UK. III. (!ii. X. PSV(JH()L(M;Y and (JONDUCT 133

llie object oC (Icsirc. Fur <3V(;n il" Lliorc- vvcin; two moving
powers, reason and desire, still tlu^y would i>roduce
inovoiiient in accordance with some eoiniuon idea. Ah a 4
matter of fact, however, reason does not appear to produce
movement independently of desire. For volition is a form
of desire^ and when one is prompted to action in accord-
ance with reason, the action follows also in accordance
with volition. But desire prompts actions in violation of
reason. For appetite is a sort of desire. Keason, then,
is in every case right, but desire and imagination may
be right or wrong. It is, therefore, always the object of 5
desire that excites action, and this is either the good or
the apparent good — yet not every good, but only the
good in conduct, and this practical good admits of varia-
tion.

Evidently the psychical power which excites to action
has the nature of desire, as we call it. In analysing 6 .
the elements of the soul, if one analyses and distinguishes 433 <^
them in terms of powers, they become very numerous, as
e.g. the nutritive, sensitive, rational, deliberative, and
desiderative. For these differ from each other more
than do the desiderative and spirited elements. Although
desires arise which are opposed to each other, as is the 7
case when reason and appetite are opposed, it happens
only in creatures endowed with a sense of time. (For
reason, on account of the future, bids us resist, while
desire regards the present ; the momentarily pleasant
appears to it as the absolutely pleasant and the absolutely
good, because it does not see the future). The moving
principle, which is the desiderative faculty as such, is
specifically one, though numerically several motive forces

134 ARISTOTLE S PSYCHOLOGY de anima

may be included in it. The main element here is the
object of desire (for this by being the object of thought or
imagination excites movement, while it is itself unmoved).

8 There are, then, three terms to consider here, first the motor
power, secondly the instrument of motion, and thirdly
the object set in motion. The motor power is twofold :
on the one hand, it is an unmoved element, and on the
other, a moving and moved element. The unmoved
element is the good to be done ; the moving and moved
element is the desiderative faculty (for the desiderative
faculty in so far as it desires is moved, and desire in
process of realization is a form of motion) ; the object
which is set in motion is the animal. The instrument
by which desire effects motion, is of course the body, and
consequently it must be investigated where we have to

9 do with functions which are common to the body and the
soul.^ One may, however, say summarily here that
motion is organic in those cases where beginning and end
are one, as e.g. in a joint. For here the convex and
concave are beginning and end. Therefore the one is at
rest and the other in motion, and while they are notion-
ally distinct, they are concretely inseparable. Everything

10 is set in motion by push or pull, and there must be con-
sequently, a fixed point, as the centre in a circle, and
this is the initial point of motion." In a word, then, as
we said before, an animal in so far as it is capable of

^ The reference is probably to the Parva Naturalia. Cf. Zeller,
Aristotle ^ Eiig. tr. vol. i. p. 89 ; Freudeuthal in Rhein. Museum^
N.F., Bd. 24 (18C9), p. 82; Rose De Aristot. lih'ortim ord. t*
aurt. p. 163.

'"^As in the illustration of the socket-joint and the circle, there is a
part at rest from which motion proceeds and a part in motion.

i«K. in. CH. X. FUNCTION OF DKSIKK 135

desire is captibk; of .seir-inovoiiK^nt. Desin^ however, in
not found apart from iina^Miiation, and all iina;^dnation is
either rational or sensitive in origin, and the lower
animals share in it.

Analogously, tlio reason is not itself in movement hut ia that from
whicli movement proceeds. The attractive thing on the one hand, and
the commanding reason or desiring mind on the other, constitute the
push and pull in animal life.

CHAPTEK XI.

We must inquire also into the nature of the moving
principle in those imperfect animals which possess only
434 a the sense of touch. Is it possible for them to have
imagination or desire ? They appear to feel pleasure and
pain, and if these are felt they must necessarily have
desire also. But how could they have imagination ? Or
are we to say that just as their movements are indefinite,

2 so too this power is possessed by them, only it is in-
definitely developed. Imagination derived from sensation
is, as we said before, found in the lower animals, but
deliberative imagination is found only in those animals
which are endowed with reason. For whether one shall
do this or that is, of course, a matter of deliberation, and
there must be some single instrument of measurement at
hand (for it is the greater good that is to be pursued), and

3 so the mind is able to make a single representation out

of several images. The ground for supposing that

animals do not have opinion is that they do not have the

faculty for drawing rational conclusions, and opinion

involves this. Consequently, their desire lacks the

deliberative quality. Sometimes the desire overpowers

136

i!K. III. CM. XI. THK M(WTN(J PRINCIPLK 1:57

the dcliborativo (ileiiUMil in 111:111 and cxciLcH to action.
At other times th(i will ()V(^r])()Wor.s the desire, and a^ain,
like a ball tossed to and I'ro, one desire over])OW(!rK
another, as in the case of intemperance. In the workinj^s
of nature the hi<j;h(!r element always has the ^'reater
authority and is the moving' power. There are, tlien,
three forms of movement.^ The faculty of conceptual 4
thouL!;ht is not moved, but remains at rest. Since we
have two principles in conduct, on the one hand the
general conception ' and notion, and on the other hand
the particular notion (of which the one says a man of
such and such a kind shall act in such a way, and
the other that this particular man — and I am that
particular man — shall act in a given way), it is the latter
notion that incites to action, but the general one does
not. Or both of them combined may lead to action,
although the general notion is quiescent, and the par-
ticular one active.

^ There is (1) the command issuing from the unmoved reason, which
acts on desire in a manner analogous to motion in the form of * push ' ;
(2) when an object stirs the desire and through the desire the reason is
awakened, the case is then analogous to motion in the form of
' attraction ' or ' pull ' ; (3) the completed process terminates in an
act of bodily or physical movement.

2Cf. Eth. nic. vii. 3, 6, lUla 1-10.

CHAPTER XII.

Every living thing must have a nutritive soul in order
that it may live and continue to live from birth until
death. What has been born must grow, reach its
complete development and decline, and this is impossible
without food. A nutritive power must, therefore, be
given to everything that grows and dies ; but sensation

2 is not necessary to all living things.^ Whatever has a
simple body cannot be endowed with the sense of touch
(neither is animal life possible without touch), and
whatever is incapable of interpreting the forms of things
without their matter is also incapable of touch. An
animal must have sensation, if it is true that nature
creates nothing in vain. For everything in the natural
world exists for a purpose, or is the condition of some-

3 thing that exists for a purpose. If, then, a body which
is endowed with the power of movement were deprived
of sensation, it would perish and would not attain the

434 <^ end for which nature strives. For how will it nourish
itself? Amongst organisms fixed to one spot, a source
of food is provided for them from which they naturally

^ Vegetable life exists only in the lowest or nutritive form.

138

itK.iii. (MI. xii. NUTKITION AND SKNSATION 130

^Tow. It is, h()Wt;v(M', iinpoHsihh; for a Ixxly Llmt is not
stationary, and is producLMl i)y ^'onOration, to liavt; life
and a thinking' mind, and yet not liavo sonnation. No
more is this possible, in bodies tliiit an; not produced by
j^onoration.^ For to what end will tlu^y lack sensation? 4
It must be because such lack will be better either for
their soul or body. lUit neither is true. For the one
will thereby think none the better, nor the other last
any the longer. Consequently, no moving body has a
soul that is unendowed with sensation. If, however, the
body is endowed with sensation, it must be either single
or mixed. The former is impossible ; for in that case ^ 5
it could not have touch, and touch is necessary. That is
clear from the following grounds. Since every living
creature is an animated body, and every body is tangible,
and tangible is that which is sensed by means of touch,
it follows necessarily that the animal body must be
capable of the sensation of touch, if the animal is to 6
persist in life. The other senses, such as smell, eight,
and hearing, perceive through other media than the
tangible body. If, however, an animal on being touched
were to experience no sensation, it would have no power
to avoid certain things and pursue others. And if this
were the case, the animal could not survive. Therefore,
taste is a kind of touch, for it is concerned with food,
and food is a tangible body. Sound, colour, and smell, on 7
the other hand, furnish no nutriment and do not con-
tribute to growth and decay. Consequently, taste must

^ Even the eternal and unbegotten bodies (stars) have the power of
sensation. Cf. De Coelo, 285a 29, 2926 2.

2 Touch implies the duality of perceiving soul and tangible body.

140 Aristotle's psychology deanima

be a sort of touch, because it is a sense that concerns a
tangible and nutritive object. Both of these senses
([touch and taste]) are necessary to every animal, and it is
evident that no animal can exist without touch. The

8 other senses exist for the sake of higher well-being ^ and
are not found indiscriminately in animal species, but only
in certain of them, viz. in such as are capable of pro-
gressive motion, and here they are necessary, For if
such an animal is to survive it must not only apprehend
an object by touching it, but must be able to do this
at a distance. This result would be attained if the
animal were capable of sensation through a medium,
and the medium were impressed and set in motion by

9 the sensible object, and if the sense-organ were in turn
stimulated by the medium. Just as a body moving in
space causes a transfer of energy up to a certain point,
and the propelling body causes another body to become
propulsive, and through the mediate term motion is
continued ; and as the initial agent moves and exerts
propulsion without being itself propelled, while the last
body in the series suffers propulsion without exerting it
and the intermediate bodies (of which there may be many),

435 rt both suffer and exert it; so it is also with the process
of change ([in sensation]), excepting that here change may
take place while the object continues on a single spot.
For example, when one dips an object in wax, movement
of the wax takes place up to the point that immersion
has taken place. A stone, however, would not be moved

^ Certain creatures are endowed merely with fitness for life, while
the endowment of others fits them for aesthetic and moral life {koXov
'4veKa ^rjv), Eth. nic. 1143a 15, 1170a 16, 1180a 10 ; rod €v eVe/ca, De an.
435& 21 ; De sensu 437a L

HK. Ml. ni Ml. SKNSA'I'ION ANM) WI-II.L KMINiJ 111

ill tlii.s way at all, wliilci vvalcr would \tv. movc^l mon; lo
lliaii wax. 'V\\v nio.sl nKihilc i^leiiKJiit, hoLli in its ]H)wer
to rtH'oivc and coininunicato motion, in the air, j)rovi(le(l
it is confiniMl and is a unit. (>onc(;rnin^ the iiIicikmikmioii
of th(> relloction of li^^ht, then, it is luitter to 8ui)po.sc that
the air, in so far as it is a continuous mass (and this is the
case upon livery smooth surface), becomes charged with
form and colour, rather than that the visual image after it
has once issued from the eye is reflected back to the
eye.^ Consequently, the air reacting on the eye stimu-
lates it, as if the impress in tlie wax were to penetrate
through to its opposite extremity.^

^ The reference is to Empedocles, who believed there was a dual
eflflux or emanation from the eye and from the object (cf. Plates Menon
76c flF., Aristot. De seiisu 438a 1 fF.) and to Plato {Timae^m, 45c).

'^That is, the visual image is supposed to penetrate through the
mass of air, as it were, to the opposite side and so pass into the seeing
organ, just as one might conceive the seal with its impress piercing
entirely through the mass of wax into something capable of receiving it
on the remote side.

CHAPTER XIII.

Evidently an animal body cannot be simple. I mean that
it cannot e.g. consist simply of the element of fire or
air. For without touch one cannot have any other
sensation. Every body endowed with soul has the
capacity of touch, as we have already said. All the
other elements, excepting earth, might become organs of
sensation, but all of them produce sensation by the

2 instrument of intermediary bodies. Touch, on the cod-
trary, appears to act by immediate contact with bodies,
and hence its name, and although the other sense-organs
effect sensation by means of contact, yet the contact is
indirect and mediated ; whereas touch is the only sense
that acts by direct contact. So then no animal body
can be constituted exclusively out of such elements ([as
are fitted for mediate perception]), neither can it be

3 constituted exclusively out of earth. For touch is, as it
were, the mediator of all tangible things, and the sense-
organ is capable of receiving not only all the various
qualities that attach to earth, but also the hot and cold
and all other tactual distinctions. Therefore we have

no sensation in our bones, hair, and other such parts,

142

UK. III. (11. xm. SKN.SI-: OK 'roUCII I1'5

l)Ocaiis(; tlicy air couHlitiiU'd out, ol" tlic cltMiient of earth.
Kor tliiH reason also plants Imvo no Hunsation, bocauHO 4.i5 ''^
they an^ coniposcd of carlli. Without touch there can i
be no other son.sation, but the or^^'aii <»!' touch is not
cuniposcd exeluHively of earth nor of any other sin^^dc
element. It is ])lain, then, that this is tlie only sense,
the (lej)rivation of which necessitates the death of
aninuUs. For neither is it possible for anything' that
is not an animal to have this sense, nor is it necessary
for anything that is an animal to have any sense beyond 5
it. Therefore, other sense-qualities, such as colour, sound,
and smell, do not by their excess destroy an animal ;
they only destroy the sense-organ, except in some acci-
dental case, as where a push or blow accompanies the
sound, and when other objects are set in motion by
sights and smells which, by their contact, work destruc-
tion.^ Flavour, in so far as it is conjoined with a 6
tactual nature,'^ works destruction by virtue of this
latter. But excess in tangible qualities such as heat,
cold, or hardness, destroys the animal. For the excess
of every sensible quality destroys the sense-organ, so
that the tangible destroys the tactual sense, and it is
in terms of this that life is defined. For it has been
demonstrated that without the sense of touch a living
creature is an impossibility. Consequently, excess of 7
tangible impressions not only destroys the sense-organ,
but also the animal itself, because this sense is the sole
requisite to animal life. An animal possesses the other

^ Simplicius {ad loc. ) thinks that lightning is meant here.

2 Aristotle would appear to refer death by poison to its tactual
qualities.

144 Aristotle's psychology deanima

senses, as we have said,^ not for the sake of life but of
a higher life. It has sight, e.g. in order that it may
see, since it lives in a medium of water, or air, or, in
a word, in a diaphanous medium, and it has taste, because
of the distinctions of pleasant and unpleasant, and in
order that it may detect these qualities in its food and
so desire it and be moved to obtain it. It possesses
hearing in order that information may be communicated
to it, and a tongue in order that it may communicate
information to others.

1 Cf. De an. 434/> 24.

(TAKVA NATIIUALIA.)
ON SENSATION AND THE SENSIBLE.^

CHAPTER I.

Now that we have treated of the soul in its essential 436 «
nature and of the faculties that belong to it, part by part,
our next duty is to investigate the subject of living
creatures and everything that has life, to determine what

^ The following opuscules of mixed physiological and psychological
content are never cited by Aristotle under a general title, but always
referred to separately. They were given the title Parva Naturalia by
the scholastics, but even the learned Leonicus apparently does not know
by whom {Comment, in Parva Natur. fol. 1530, p. 11), and Simon is
only able to say ^ ' denominatio a Latiuis inventa est" {Coram, in lihr.
de sensu, 1566, p. 1). The designation is used by Egidio Colonna (cf.
Rhein. Museum, vol. 24, 1869, p. 81), who was a pupil of Thomas
Aquinas, and we may assume that the title came into existence about
the time of Thomas, when great interest was taken in the interpretation
of the Aristotelian writings, although Freudenthal was unable to find it
either in Albertus Magnus or in Thomas. The tractates discuss, in the
main, the organic functions of animal bodies, and form at once a con-
tinuation and supplement to the De anima and an introduction to the
treatise On the Parts of Animals. They form thus a transition from
Psychology to Zoology. In content they are mainly biological and physio-
logical, concerned chiefly with the physiology of the senses. They
supplement the De animain the following particulars: In the De anima the
soul is regarded as the principle of organic life, which is manifested iu
the forms of cognition and physical vitality. The detailed consideration of
the relation between these two things is left for the Parva Naturalia ;
K 145

146 Aristotle's psychology desensu

functions are specific^ and what functions are general. Let
us then take what has already been said touching the
soul for our basis, and as we proceed to the remaining
inquiries let what is first by nature ^ be first in our dis-

2 cussion. The most important vital phenomena, whether
one regards the specific or general attributes of animals,
are those which are the joint concern of soul and body,^
such as sensation, memory,"* anger, desire, and impulse in
general, and, one may add, pleasure and pain. These are

3 experienced by almost all animals. In addition to these,
however, there are other attributes which are common to
all animals that share in life, and others still that belong
only to certain animals. The most important of the
former class may be enumerated in four pairs, viz.,
sleeping and waking, youth and old age, inspiration and
expiration, life ^ and death. We must study the nature

further, the nature of memory, the association of ideas, and the subject of
dreams, are treated almostexclusively in the opuscules. Thebrief accounts
of 'common sense,' pleasure and pain, and motion in the De anima are
supplemented here. Further, such biological considerations as the con-
ditions, disturbances, and duration of organic life were scarcely noticed
in the De anima, but receive detailed treatment in the tractates On
Youth and Old Age, Life and Death, and On Respiration.

^ Reason and Recollection e.g. are specific functions, while nutrition
and growth are general and common to all living organisms.

2 By this is meant the elemental functions connected with the life of
the body {kolvo. ttJs ^vxv^ Kal tou Tilj/xaTos ^pya), on which depend nutri-
tion and reproduction, sleeping and waking, etc.

■^Dean. 433& 19, 20.

* Memory [fiu-qix-q) but not recollection {av&ixviidLs) , which involves
reflection, and is peculiar to man.

'' To these four pairs of biological phenomena is added a fifth below —
health and disease. Youth and old age, life and death are treated in
one opuscule, sleeping and waking in another, inspiration and expiration
in another, while the subject of health and disease was either not
treated at all, or the treatise has been lost. No such treatise was
known to Alexander Aphrodisiensis (Comment, ad 436a 17).

CHAP. r. 1»UUP()S1«: OF SKNSA'J'ION 147

of each of thoso plK'iioineim and tho causes of its occiir-
roncG. Tli(^ iiivestijj^atioii, Loo, of Uie ultimate^ j)rincij)lcs
of health aiul ilisoaHc is the provinoe of the naturalist; for 4
neither health nor disease can apply to creatures when
deprived of life. And so it happens, as I think, that
most natural j)!iilosophers and those; physicians who have
a more philosophical understandini; of their science, con-
clude in the one case with the investigation of medicine,
and in the other begin their practice with deductions 436^
from the laws of nature and their application to medi-
cine.^ The above-mentioned phenomena are evidently 5
the common property of soul and body. For they are
all conjoined with sensation or are mediated by it. Some
of them are modifications of sensation or persistent condi-
tions of it, others are protective or preservative of
sensation, while others still are destructive and negative.
That sensation is mediated by the body to the soul is plain
both with and without the use of rational proof. How-
ever, regarding the essential nature of sense-per^.eption
and the reason why animals are endowed with it, we have 6
already stated our views in the treatise On the SouL"
Every animal, in so far as it is a living creature, must
have sensation. For it is in terms of this that we
distinguish between animal and non-animal. Touch and 7
taste must belong to all animals individually, touch
for reasons given in the treatise 0?i the SouV^ and
taste on account of food. For it is by taste that animals

^ Cf. 480/> 25, where the tractate on Respiration closes with an
almost verbatim repetition of this statement.

-In the De an. the purpose of sensation is described as two-fold,
(1) the survival of the animal, (2) the ends of higher living (cf. 420Z>
20 ff., 4346 22 ff.).

148 ARISTOTLE S PSYCHOLOGY de sensu

discriminate between agreeable and disagreeable in foods,
and so reject the one and take the other; in a word
flavour^ is an affection that belongs to the nutritive

8 soul. Sensations that are excited by external objects,
such as smell, hearing, and vision, are found in animals
capable of locomotion, and are given to all of them
for the sake of their preservation, in order that they may
scent their food and pursue it, and flee from what is
harmful and destructive. In the case of animals endowed

437 a with intelligence, they are given for the sake of higher
well-being. For these sense-perceptions convey to us
various distinctions, out of which the knowledge of intel-

9 lectual and moral concepts is built up. Amongst the
senses, vision is the most important, both in itself and for
the necessities of life ; on the other hand, for the uses of
reason, and accidentally, hearing is the most important.^

10 The power of vision informs us of many and various dis-
tinctions, because all bodies are suffused with colour, so
that by means of this sense more than by any other we
perceive the common properties of objects (by common
properties I mean form, magnitude, motion, number).
Hearing, on the other hand, informs us merely of dis-
tinctions in sound, and in some instances of distinctions in

^ That is, flavour as a property of food affects the process of growth
or the nutritive soul. Touch is the lowest or most fundamental
sense, and taste is a form of touch mediated by the tongue. These two
serve the primary or lowest ends of life. Sight and hearing serve the
higher or more intellectual needs.

- Although sight conveys to us the greatest number of impressions
touching the outside world, Aristotle considers hearing the most
important of the senses intellectually, because it mediates oral instruc-
tion. This is called per accidens, because per se the hearing mediates
only sound, and it is accidental to the function of hearing that this
sound should be significant or have meaning.

cMAi'. I. TMT'OUTANCK OK Tri<:AHIN(; Ml*

articulates voice Indirectly, hovvovcr, hojirini» contiihutes u
the ^rcatoHt Hluin^ l(» our iijt(;lli;ctuiil lilc. For it is the
spoken and l»c;ird word tliiit is tho .source of knowlcMl^e,
and hearin*^^ is the source not, in itstdl" but accidentally.
Lan^uaj^e is coniposml of words, and (ivery word is a
symbol. This ex])lains the fact that in cases where men 12
are deprived of one or the otiier of these senses from
birth, the blind are more intelligent than the deaf and
dumb.^

^ This is no doubt correct, owing to the advantage the l)lind liave
over the deaf and dumb in the use of language. Tliis advantage has
been greatly modified, of course, by the development of linguistic
instruction for the deaf and dumb. The necessity of language for
thought is a still unsettled question. C^f. James, Prinriples of
Psychology, Vol. I. p. 269, who considers language, in its ordinary
meaning, unnecessary for thought. Sully ( The Human Mind, Vol. I.
p. 420), on the other hand, says : "It seems safe, therefore, to conclude
that apart from verbal or other general signs the full consciousness of
generality does not arise." Romanes {Mental Ecolution in Man, p. 149):
" These unfortunate children [i.e. the deaf and dumb who are never
taught finger-language] grow up in a state of intellectual isolation,
which is almost as complete as that of any of the lower animals."

CHAPTEK 11.

We have already treated of the function of the several
special senses. Writers now-a-days attempt to correlate
the senses with the physical elements ^ as found in the
bodily members in which the sense-organs have their
natural development. With the fifth sense they are
hard pressed, not finding it easy to pair five senses with

2 four elements. All of them agree in regarding vision as
connected with fire, on account of a certain phenomenon
whose nature they misunderstand : viz. when the eye is
pressed and moved it seems to scintillate." But this
takes place in the dark or when the eyelids are shut, in
which case darkness is produced. And there is also

3 another difficulty here. For if it is impossible for a
perceiving and seeing subject to be unconscious of a seen
object, then the eye must necessarily see itself. Why,
then, does this not take place when the eye is at rest ?
The explanation of this phenomenon, as well as the
solution of the entire difficulty and of the apparent fact
that vision is fire, is to be found in the following con-

^ Empedocles, Alcmaeon, Democritns, Plato.

^ Pressure on the optic nerve, of which Aristotle knew nothing,
stimulates the sensation of light.

150

DK 8KNHU

TIFK OHdANS OK SKNSK 151

sidemtiona. It is Uio imlun» of Hiiioolh Hurfaces to shine 4
in the (larknoss, althou^Mi thoy ])ro(lucM'. no li<^'ht ; now we
observe th.it the dark central portion of tlie eye has a 437 ^
smooth surface. This boconies apparent when tlie eye is
moved, because the single organ is thereby made doul)le,
an ellect wliich is produced hy the rapidity of the motion.
In this way the seeing organ and the seen object appear s
to be different.^ For the same reason, also, this effect
fails to be produced, when the motion is not rapid and
does not take place in the dark.^ For it is in a medium
of darkness that a smooth surface naturally shines, as we
see in the case of the heads of certain fishes ^ and in the
juice of the cuttle-fish. The consequence is that when the
eye is moved slowly, the seeing organ and seen object do
not appear to be at once unitary and dual. When, on 6
the other hand, the movement is rapid the eye sees itself,
as in the reflection of a mirror. Now, if vision were fire,
as Empedocles declares and as we read in the Timaeus,^
and if seeing resulted from the passage of light out of the
eye as from a lamp, the question arises : Why is it that 7
we do not see in the dark also ? To say, as the
Timaeits^ does, that the light when it passes out from
the eye is extinguished in the darkness, is a totally empty
assertion. For what is meant by an extinction of light ?
The warm and the dry, it is true, are nullified by the
moist and the cold, as one sees in the case of a coal fire

^ That is, the seeing eye, which according to Empedocles is fire,
appears to be seen and so to be different from the eye itself.
- Because the smooth surface shines only in the dark.
^Cf. Dean. 419a 5.
■* Timaeus, 42 e, 43 a ff. ; Meno 76 c.
^ Timaeus, 45 b ; cf. also Theaetetiis 156 c.

152 Aristotle's psychology desensu

8 or a flame, but neither of these has anything to do with
light. If, however, they ^ are attributes of light but are
concealed from us owing to their subtle presence, then
light ought to be extinguished in the day during rain, and
darkness should increase in frosty weather. Flame and
ignited bodies are so affected, but nothing of the sort takes

9 place in the case of light. Empedocles appears to hold
the view that vision results from the eye's radiating light,
as we said before. His own words, at any rate, are as
follows " :

"As a man taking thought for his journey
A lantern prepares, whose flame flashes light
Through the blustering niglit, as he passes,
And shutters he fastens, defence from winds,
To scatter the breath of the blowing blasts.
While the light pierces through, by its fineness,
And gleams over the threshold unfailing ;
So, of old,^ fire elemental was fixed
438 rt In membranes, and suff"used* the round pupil.

Held in thin tissues, a check to the water.
While the fire pierces through, by its fineness."

10 Sometimes he gives the above explanation of vision,
and at other times he explains it by means of emanations
from visible objects.^

^ The warm and the dry.

2Cf. Burnet, Early Greek Philosophy, p. 231.

^ Instead of to t' read t6t'.

■* Instead of Xoxd^ero read ix^^o-ro.

^ Each of these parts represents only half of the Empedoclean
tlicory of perception. Light emanates from the fire in the eye, as from
a lantern, and effluences come from sensible objects. These efliuenoes
enter into the pores or passages of the eye, and in proportion as these
eSluxes are fine or crass, they enter into the larger or narrower
passages. The fire is in the interior of the eye, ami between this and
the outer covering is a mass of water held by a fine net. The fire ia

(!iiAi-. II. Til MO KIMS OK VISION \'>'^

Donioc'.ritua says that vision i.s duo to water, an<l in
this ho is ri«^ht ; l)iit hi^ is wron;^ in tliinkin)^ that it
consists in n^llootidu. Kor rollootion is produced l)ocause
tlio oyo is a smooth suilace ; vision, howover, doos not
take |)hic(' in this smooth surfacM; Imt in the seeing
snhject. Now, the condition to which he refers is only a
reflection of light. lie has, however, as I think, no cluai
idea whatever concerning the general nature of images n
and reflection. It is also strange that it never occurs to
him to raise the question why it is that the eye
alone sees, while no other object in which images are
reflected, has vision. His statement that vision partakes
of the nature of water, is true ; but vision is not due to
the fact that the eye is water, but to the fact that it is
transparent, which characteristic it has also in common
with the air. Water, however, is easier to fix and is 12
thicker than air, and it is for this reason that the eye and
its pupil are composed of water.^ This can be proved
also from actual facts. When the eyes are destroyed
water is seen to flow out of them, and even in their quite
embryonic stage the eyes are exceedingly limpid and
brilliant. Further, the white of the eye^ in sanguineous ^3
animals is fat and oily, which serves the purpose of
keeping the humid element from congealing. Conse-
quently, the eye can resist cold better than any other
organ of the body. No one ever experienced the sensa-

the interior by reason of its fine, subtle nature, penetrates through these,
as the light penetrates through the sides of the lantern and out through
the atmosphere. In this way the images thrown oflf from things are
illuminated. Cf. Burnet, Early Greek Philosophy, p. 265.

^ The aqueous and vitreous humours.

2 The sclerotica.

154 Aristotle's psychology desensd

tion of cold in the interior of the eye. The eyes of
bloodless animals are covered with a hard skin
which furnishes protection. The theory is altogether

14 irrational which makes vision consist, as some hold, in a
sort of radiation, and regards this radiation of something
from the eye as extending to the stars, or as extending
to some point and there effecting a combination with the
object. It would be better to assume that this com-
bination of the eye with its object were in the eye's
original nature. But even this is nonsense. For what
is one to understand by this combination of light with
light ? Or how is such a thing to take place ? For

438 b nothing combines in a haphazard way with anything else.

15 Further, how can the internal light combine with an
external one, for between them is the intervening
membrane. Resfardin^ the fact that there is no vision
without light, we have spoken elsewhere.^ But whether
the intervening medium between the visible object and
the eye is light or air, it is in any case the motion
through this medium that produces sight. And it is
reasonable to regard the interior of the eye as composed

16 of water ; for water is diaphanous. And as nothing
external is seen without light, the same thing applies to
the internal. The internal also must, therefore, be
diaphanous. Since this diaphanous is not air, it must
be water. For the soul or the perceptive power of the
soul is not found on the eye's surface, but evidently

17 within. Consequently, the eye's interior must be
diaphanous and sensitive to light. And this we can see
empirically. For cases have happened in war where

1 Dt an. 41S/> 1, 419a 9, 430a IG.

riiAr. II. THK ORCJANS OF SKNSK IW

persons liave received sucli a Mow across t!i(; temples '
that the ocular conduits were severed and darkness
seemed to ensue, just as wluui a lamp is j)Ut out, and
this is (hu; to the fact that the diaphanous, i.e. the
])upil as we call it, was cut off, as in the snulhng of a i8
lamp. If, therefore, this takes place in some such way as
we descril)e, it is evidently necessary to render an expla-
nation of this kind and to correlate each sense-or<^an
with one of the elements, viz. the seeing power of the
eye we must derive from water, the sense for sound from
the air, and smell we must associate with tire. For the
organ of smell is potentially '^ what smell itself is 19
actually. The sensible object stimulates the sensation
into actuality, and consequently the latter must have an
antecedent potential existence. Smell ^ is a smoke-like
exhalation,"* and this is derived from fire. It is for this 20
reason, too, that the organ of smell is especially assigned
to the environment of the brain, for the material sub-

^ The eye must be translucent, and therefore composed either of air
or water, in order to transmit vision to the inner soul, vision not taking
place on the eye's surface. This is proven by the fact that when the
optic passages are severed, as Aristotle supposes, by a blow on the
temple, one becomes blinded.

2Cf. Dean. 417a 12fif.

=^ Be ail. 421a 7 ff.

■* Smell is considered by Aristotle one of the most difficult senses to
analyze, which is due to the fact, he thinks, that it is very imperfectly
developed in man. Taste is closely allied to it, but much better
developed. The one is concerned with the ' sapid dry ' (443a 7) and the
other with the * sapid moist.' Flavour is found in the moist only,
while for respiring animals odour is found only in the dry. It can,
however, exist in the moist as shown by the sense of smell in aquatic
animals. For the latter reason it cannot be a * smoke-like exhalation.'
Aristotle appears here to be speaking only in terms of a current
explanation. Cf. 443a 23 fF.

156 Aristotle's psychology desensu

strate of cold is potentially warm. And the same
explanation holds good for the development of the eye.
It is formed from a part of the brain, for the brain is the
21 moistest and coolest member of the body. The organ of
touch is derived from the element earth, and taste is a
439 a form of touch. Consequently, the organs of these two
senses, taste and touch, are found to conduct towards the
heart. The heart occupies a counterposition to the brain
and is the warmest member of the body. Eegarding the
sense-organs of the body let the above determinations
suffice.

CHAPTER III.

In the treatise On the Soul ^ I have given a general
account of the objects of sense in their application to the
several sense-organs, such as colour, sound, smell, flavour
and the tangible. I have explained their function and
their activity, organ by organ. But we must also deter-
mine what each of these things is apart from the organ,
e.g. we must ask : What is colour ? What is sound ?
What is smell ? What is flavour ? We must likewise
inquire regarding the tactual, and we must begin with
colour. Everything has a twofold significance, viz. that 2
of actuality and potentiality. It has been explained in the
treatise On the Soul ^ in what way actual colour and actual
sound coincide with and differ from the actual sensations
of seeing and hearing. We must now explain what each
of these sensible objects must be in order to produce
sensation and its activity. We have already said in the
above-named treatise regarding light that it is the colour 3
of a diaphanous medium, accidentally produced.^ For

1 Be an. 418a 26— 424a 16. 2 j)^ ^^^ 4256 29 ff.

^ Neither colour nor light belongs to the essential nature of the pel-
lucid medium, which may be charged at one time with one colour and
at another time with another, or in the case of darkness it maj' suffer
privation of light.

157

158 Aristotle's psychology desensu

when anything fire-like is found in the diaphanous, its
presence constitutes light and its absence signifies dark-

4 ness. What we understand by diaphanous is not a
property peculiar to air or water or to any other
so-called body, but it is a certain natural constitution
and power, ^ common to both these bodies and found
also in certain others, in greater or less degree, but
which has no independent and separate existence. And
furthermore, as there must be a limiting surface in

5 bodies, so here also. Light is found in an indeterminate
diaphanous. It is also evident that the diaphanous in
bodies must have a surface, and that this surface is colour
is plain from observed facts. For colour is found either
in the boundary or it is itself the boundary. It is for
this reason that the Pythagoreans ^ characterized the
visible superficies as colour. Colour, indeed, is given in

6 the boundary properties of body, although it does not
itself constitute that boundary. On the contrary, one
must suppose that the same colour-quality^ which is

439/; observed on the exterior applies also to the interior.*
Both air and water are seen to be coloured, for even their

7 shimmer is colour. In these cases, however, air and

^ Aristotle rejected the view of Empedocles that light is motion and
travels from heaven to earth (4186 20, 446a. 26). Light is not motion,
although it is caused by movement or change (dWoicoais). In its own
nature it is a definite qualitative condition of the air or water, just as
the frozen represents a condition of water (4466 28 — 447a 3),

^Cf. Plut. Epit. Mem. I. 15; Stohaei Eclog. I. 15 quoted by Diels
Dox. Or. p. .313.

^The treatise On Colours {irepl xpw/udro;;/) is not genuine. Cf. Prantl,
Aristot. iiber die Farhen, pp. 82-84.

■* Aristotle appears to have in mind such objects as jewels, whose
colour he considers not merely superficial but as penetrating through the
substance.

CUM'. 111. TllK UIAJ'HANOITS 109

the sea, because of iIkmi' imlixed character, do not have
the same colour when viewt'd luvdv ;il liaiid and from a
distance. In solid bodies, on tlu^ other hand, tlu^
appearance of the coU)ur is fixed, unh.'ss tiie surrounding^'
niedimn makes it sliift. It is evident, therefore, that the
principle which is sensitive to colour is, in both the former
and tile latter instances, the same. The dia])lianous,'
then, in so far as it is found in bodies (and it is found 8
more or less in them all), causes them to be satu-
rated with colour. Inasmuch as colour is found in the
boundary of bodies, it would also be found in the
boundary of the diaphanous substance. Consequently,
colour might be defined as the boundary of the diaphanous 9
in a definite body. Colour attaches also to diaphanous
bodies themselves, such as water and other similar
elements, and it is also found in all such bodies as have
a surface-colour which is peculiar to the body "" itself.
There is then, on the one hand, the possibility that the
positive principle which in the air produces light should
also be contained in the diaphanous ; on the other hand,
it is possible that this should not be the case, but that
the condition then should be one of privation.

As in the case of air we have the two phenomena,
light and darkness, so in bodies we have the two qualities, 10

^ The diaphanous is that which mediates colour, and light is that
which converts the potentially diaphanous into the actually diaphanous.
In other words, a diaphanous or pellucid medium, such as air or water,
is not actually pellucid without light, but is dark. Colour has the
power to set the diaphanous in motion (419a 10), by which means the
images of remote surfaces affect the visual organ.

2 Fire or some positive principle such as is found in the aether is sup-
posed to illumine the diaphanous ; the withdrawal of this is darkness
or the privation of light.

160 Aristotle's psychology desensu

white and black. Eegarding the other colours we must
now decide, after analysis, in how many ways they can
be produced. For black and white may be so juxtaposed
that each of the two, on account of its minuteness, when
taken alone will be invisible, while the combination of
the two will be visible. The latter cannot be seen

11 either as white or black. But inasmuch as it must have
some colour, and it can be neither of these two, it must
be a mixed colour, and different in kind from the others.
It is, then, a possible supposition that there are several

12 colours besides white and black, but their manifoldness is
due to proportion.^ This proportion can be expressed by
the relation of 3 : 2 or of 3 : 4, or colours can be related
to each other in terms of other numbers, and some may
not be expressible at all in terms of any proportion, but
in terms of some incommensurable plus and minus. The
same thing applies also to harmony of tones. Those
colours which are expressed by harmonious numbers, as is
also true of tone-harmonies, appear to be the most pleasing,

440 a such as sea-purple, crimson, and a few others like them ;
they are few for the same reason that harmonious tones
are few.^ The other colours are not numerically expres-
sible. Or, is it true that all colours are numerically

^ White and black, the correlates of light and darkness, are the
basal colours, as sweet and bitter are the basal flavours. Between these
two extreme opposites there are intermediate colours, into which the
primary colours are convertible by composition {Phys. 188a 32 ; 1886 21 ;
2296 14; Metaph. 1057a 23). These intermediate colours are red,
violet, green, blue, and yellow. Gray is included in black, and is not
regarded as an independent colour, while yellow is perhaps included in
white (442a 22). Cf. Goethe, Farheiilehre (ed. 1810), Bd. II. pp. 11-53.

"^ In the first place because they do not form a continuum, and so are
not infinitely or indefinitely divisible, and secondly because they are
objects of feeling.

cMArMii. THEORY OF COLOURS H)!

expressible, althou^^'h some colours depend upon ti re<,ailjir
order, while others depend upon an irre^'ulur order, and
the latter have this character when they are not pure ?
This is one^ explanation of the genesis of colours ; another'
explanation is that they shine throuj^di one another, as we 13
see sometimes in the works of artists, when they superadd
a colour on a back<^round of a difl'erent colour, e.g. when
they wish to produce the efVect of an object seen in the
water or in the air. So it is also with the sun, which in
its own nature appears white, but red when seen through
mist and smoke. And many other colours will be pro- 14
duced in the same way as above described. That is to
say, a certain proportion might be supposed to exist
between the colours on the superficies and the colours in
the depths, and others again may not be expressible in
terms of 'proportion' at all. It is, therefore, absurd to 15
say with the ancients that colours are eftluxes, and for
this reason are visible. For in their opinion it is
absolutely necessary that sensation be effected through
contact, and it is consequently better to say at once that
the medium of sensation is set in motion by the sensible
object, and that in this way sensation is produced by
contact and not by effluxes. In the case of juxtaposed 16
colours, just as one must suppose an invisible magnitude,
so must one suppose an imperceptible moment of time,
in order to explain the fact that the movements issue
imperceptibly, and because they are simultaneously visible
the impression is a single one. There is, however, no
such necessity here, but the colour on the superficies

^ Viz. the number- theory which Aristotle rejects.
2 xA.lso this theory of superposition is rejected.

162 Aristotle's psychology desensu

when unmoved, and when set in motion by its substrate,
produces unlike motions in the medium. Consequently,
it appears different, and neither white nor black. So

17 that if an invisible magnitude is not possible, but every
magnitude must be visible from a certain distance, so
there must be here also a certain mixture of colours. In
this way one may suppose that in objects viewed from a
distance a certain common colour is seen. For that there

18 is no invisible magnitude is a matter that must be in-
440 ^ vestigated later. If a mixture^ of bodies takes place, then

it is not merely in the way that some think, viz. by the
juxtaposition of minimal parts which are imperceptible to
our senses, but also in the form of a general mixture of
the entire substance together, as explained in outline in

19 our treatise On Mixture} By the former method of com-
position only those substances can be mixed which are
capable of analysis into minimal parts, e.g. men, horses, or
seeds. In the case of ' men,' a man is the minimal
part;^ in the case of 'horses,' a horse. Consequently, in
both instances the mass is formed by juxtaposition of
these minimal parts. We do not, however, speak of a

20 man being mixed with a horse. Whatever cannot be
analysed into minimal ([homogeneous]) parts, is incapable
of mixture in this sense, but only in the sense of total

^ The first two theories, viz. the numerical and the superpositional,
are here rejected in favour of the theory of substantial mixture.

^ This treatise {irepl /xi^ews) has been lost. For Aristotle's definition
of mixture, and his distinction between it and synthesis, see De gen. et
corr. 328a 5 ff. The former implies homogeneity, while the latter
may be merely mechanical juxtaposition. The former produces a whole,
the latter an aggregate (321a 34).

•^ Read i\ix'-<^Tov for Adx«a^Tos. Cf. Berliner Wochen-'ichri/t fur class.
Philoh, 1898, p. 998.

t'liAi'. III. (^(H.OUK, AND MIXTUKK lO.'l

iiiixturo, wliicli is wliat luiturally liikcH place in nioHt
caHOH. In our treatise On Midttrr W(^ liave already
explainiul how this can take j)laee. Wh(;re bodies are 21
mixed their colourH must evidently 1x5 mixed also,
and this is the ])rinei})al cause of the multiplicity of"
colours, which is not explained by their being super-
posed or by their iuxta])osition. It is not true that
what is mixed has one colour when viewed near by, and
another when viewed at a distance, for it has one colour
when viewed from all points. And colours will be
manifold because of the possibility of manifold proportions 22
being employed in mixtures, some of which will be based
on numerical proportion, others on that of disproportionate
mass. Further, the same thing may be said of mixed
colours as was said of juxtaposed and superposed colours.
The explanation of the fact that we have fixed and
definite varieties of colours, flavours, and sounds will be
given later.^

1 Cf . De sensu, 4456 3 ff. ; 446a 20.

CHAPTEE IV.

We have now explained the meaning of colour and the
cause of its multiplicity. We had already discussed
the subject of sound and articulate speech in the treatise
On the Soul} Smell and flavour now remain to be
discussed. Both these terms signify almost identical
natural affections, only each of them is found in a

2 different organ. The quality of flavours is more distinct
to us than that of smells. The reason is that our sense

441 a of smell is inferior to the same sense in other animals,
and is inferior to all our other senses, while we of all
animals have the most accurate sense of touch, and taste

3 is a sort of touch.^

Water in its own nature has no flavour. And yet
it is necessary that water should contain within itself
the varieties of flavours, which owing to their infini-
tesimal character are indiscernible, as Empedocles^ says,
or else there must be in water some such matter as is

1 De an. 420b 32. ^De an. 423a 19.

•^ Other than this we have no knowledge of the Empedoclean theory
of taste, with the exception of the statement in fr. 139 that flavours
depend upon adaptability to the sense-pores. Cf. Burnet, Early Oreck
Philos. p. 265.

164

DKHKNHU NATURK OK FLAVOURS 105

the uiiivcrHul i^'oriii-ori^^in (if llavours/ and in this way
all llavours are generaUid uul of water, dilVercnt llavourH
t'roni difVerent ])arts ; or a|^ain, HUpposing that watn
contains no qualitative dilVerenceH, we must then find
some other efficient cause of flavour, such as hc.at r>r
the inliuence of the sun. The error of the JMnpedoelcan 4
theory is very easy to detect. For we actually observe
flavours undergoing change under the inliuence of heat,
<'.//. when we expose fruits to the sun by removing
their pericarps or by heating them before a fire. They
do not acquire this new flavour by drawing it out of
the water, but by undergoing a change in the removal
of the pericarp itself When fruits are dried and stored
they become in time, instead of sweet, pungent or bitter,
or change their flavour variously, and when cooked they
acquire, so to speak, all sorts of flavours. So too, the
theory that water is a panspermic matter is impossible. 5
For we observe that out of one and the same thing,
as out of the same food stuff, different flavours are
generated. There remains the theory that water by
undergoing some external influence, changes. It is plain 6
that the phenomenon which we call flavour is not due
to the potency of heat. For water is the thinnest of
all liquids, subtler than oil itself. Oil, however, is more
expansile than water because of its viscous character,

^ I think the reference here is more likely to Anaxagoras than to
Democritus, as Wallace supposes (Aristotle's Psychology, Introd. p. Ixvi),
although both of them are said to have used the term TravaTrepfiia. The
description of the theory {4:4\a 19) as one of dynamism would conform
better with the general principles of Anaxagoras than with the
mechanical philosophy of Democritus. In strictness, iravaTrepixla is a
term which Democritus could not legitimately use.

166 Aristotle's psychology desensu

water being non-cohesive. For this reason it is harder
to hold water in one's hand than it is to hold oil.

7 Now, since water is the only liquid which when heated
exhibits no denser consistency than before, we must
evidently look elsewhere for the cause of flavour. For
all flavours are more dense when heated. Heat is a
contributing cause ([not the sole one]). Apparently the

441 /; flavours that are found in fruits have a prior existence

8 in the earth. In the same spirit many of the ancient
physiologers ^ say that water is like the soil through
which it passes, and this is particularly evident in the
case of salt waters, for salts are a form of soil. Also,
water that has been filtered through bitter ashes acquires

9 a bitter taste. Further, we often find springs that are
bitter and others that are pungent, while others still
have different flavours. The greatest variety of flavours
is found, as one might suppose, amongst plants. It is
the nature of moisture, as of other things, to be affected
by its opposite and its opposite is the dry. Conse-
quently, it is affected by fire, which is by nature dry.

10 Now, heat is the peculiar property of fire, and the dry
is the peculiar property of the earth, as was said in
the treatise On the Elements!^ Neither fire, nor earth,
nor any other element, as such, acts or is acted upon.
It is only in so far as each thing contains in itself the
principle of opposition that it either acts or is acted upon.^

' Lewes fiuds this idea expressed in Hippocrates. Cf. Aristotle, p. 250.

2 The reference is probably to De gen. et corr. 329ft 18-3306 9. On
the lost treatise trepl <jtolx^Iu}v see Heitz, Die verlorenen Schriften d.
Aristoteles, p. 70.

•'A thing acts or is acted upon through certain of the qualities
possessed by it and through the action of opposing qualities.

oiiAiMV. FLAVOUR AND MOISTURK 167

As, theroforo, those who diasolvo a colour or ;i n
Havour in waiter, causes tho water to absorb it, ho
iiaturo acts u])on tlio dry and (uirthy elements, and
by filterin*^' water throu)^di these (dements and stimu-
latin<^' them into activity by heat, it causes the moist
element to ac(|uire a certain ([uality. This condition, 12
which is wrought in moisture by means of the above
mentioned dry element, is Havour, and it consists in
the conversion of a potential jtaste into an actual one.^
For the sense-organ which is already in a condition of
potentiality, passes over into a condition of actuality.
The process of sensation does not resemble learning so
much as it resembles contemplation. That flavours do
not attach to everything dry, but only to the dry that 13
is nutritive, either as a positive or negative condition,
one may conclude from the fact that the dry is not
found apart from the moist nor the moist apart from
the dry. Neither one when taken alone is food-stuff
for living creatures, but only when combined. In
animal food it is the tactual elements which effect 14
growth and decay. And it is by virtue of the warmth
or cold ill the assimilated food that these phenomena
are produced. For these are the properties that cause
growth and decay. The administered food nourishes in 442 a
so far as it is gustable. For everything is nourished
by means of the sweet, whether pure or mixed. This 15
subject must be more definitely treated in the work

^ The gustable or flavour (xv/xos) is described at 4416 19 as an efifect
produced in a moist substance by that which is dry. Flavour is
therefore, the sapid moist, while the object of smell is described (443a 2)
as the * sapid dry.' The odoriferous and the gustable (savour and
flavour) are closely allied.

168 ARISTOTLE S PSYCHOLOGY de sensu

On Generation ^ ; for the present we only touch upon
it so far as necessary. Heat disposes to growth and
brings food into a prepared condition ; it absorbs what
is light and rejects the salt and bitter because of
their heaviness. What external heat effects in external
bodies, is also produced by internal heat in animals
i6 and plants. Nourishment, then, is caused by the sweet.
The other flavours are mingled in food in the same
way as the bitter and pungent, i.e. to serve as a
relish. This is for the purpose of counterbalance, and
because the sweet is over-nutritive and swims on the
stomach.

As colours are a combination of white and black, so
flavours are derived from sweet and bitter. They depend

17 severally on a proportion of more or less, on a proportion
of mixture and motion either numerically expressible, or
indeterminate. Those mixtures, however, which produce
pleasure are numerically expressible. The oily flavour is
to be classed with the sweet ; the salt and bitter are
closely allied, while the sour, pungent, astringent, and

18 acid are intermediary. And so the varieties of flavours
and colours are pretty nearly the same in number; for
there are six of each, if one regards, as is reasonable, the
gray as a sort of black.^ We have then to include
yellow in white, just as we referred the oily flavour to the

^ Aristotle is here referring to the subject of growth and decay, not
to the nature of taste. The subject is treated in De gen. et corr. 320a
8ff.

2 And further, if one regards yellow as a species of white. Otherwise
we have seven colours as enumerated at note 2, p. 87. I have retained
iSusemihl's conjecture i^ for eirrd, adopted by Biehl (cf. Alexander
Aphrod. Comment, ad loc). Prantl, however, calls the Aporia of
Alexander '* ungeschickt" {Aristot. Ueber die Farhen, p. 117).

<'HAi'. IV. TIIK SMNSK OK TOUCH 109

Hwoot, while, crimson, Hea-pui'ple, ^nuiii, and Mnc, ai(»
intcruuHliary bctwccni wliitc, and Mack, and all oUht
shades are combinations ol' these. Ah black is privation 19
of the whiter in a diaphanous medium, so the salt and
bitter are privation of the swcict in a nutritive; moist
substance. Conseciuently the ashes of anythin;^' that has
been burnt are bitter ; for the potable element has been
consumed.

Democritus and most of the physiologers who treat the
subject of sensation make the most remarkable blunder,
for they resolve all sensible objects into the tangible. If, 442/^
indeed, this is correct, each of the senses becomes evidently 20
a sense of touch. It is not difiicult to see that this is
impossible. Further, they treat the common functions of
all the senses as special functions. For the perception of
magnitude, figure, roughness, smoothness, and sharpness
and bluntness in solid bodies, is the common function of
all the senses, and if not of all, then at least the common
function of sight and touch. It is in these perceptions, 21
therefore, that the senses are subject to error ; but they
are not subject to error in their special sensations,
e.g. sight is not fallible regarding colour nor hearing
regarding sound. Again, these physiologers refer the
special functions to the general, as Democritus does with
white and black,^ the latter of which he identifies with
the rough and the former with the smooth, and he

^ White is due to smooth atoms and their aggregation is a smooth
surface. Black is due to rough and uneven atoms and their aggrega-
tion is a rough and uneven surface (cf. Theophrastus, De seiisu, 73).
Further, however, the quality of the visible is affected by the rapidity of
motion in the effluxes and by the condition of the air itself (Theoph.
De sensu, 80).

170 Aristotle's psychology desensu

reduces flavours ^ to atomic forms. And yet it is
either not the function of any sense to discern common
properties, or else this power belongs to the eye more

22 than to any other organ. If, however, this power
falls rather to the lot of taste, it is at any rate the
function of the most delicate sense to discriminate the
slightest distinctions, each after its kind, so that taste
would have to discriminate common properties better than
any other sense and be the most discerning judge of

23 atomic figures. Further, all sensible objects contain the
principle of opposition, e.g. in colour black is the opposite
of white, and in flavour bitter is the opposite of sweet; but
one figure does not appear to be the opposite of another
figure, for to what sort of polygon would a circle be

24 opposed ? Further, the atomic figures being infinite in
number, it necessarily follows that flavours are also
infinite in number. For what is the explanation of the
fact that one flavour produces a sensation and another
flavour does not produce it ?

We have now treated the subject of the gustable and
flavour. The other aspects of flavour receive their
proper consideration in the treatise On the Physiology of
Plants?

^ Flavour-qualities are explained by Democritus in a way similar to
variations in colour, i.e. white and black are analogous to sweet and
bitter. Sweet is due to round smooth atoms ; bitter to rough and
angular ones (Theoph. De sensu, 65, 66).

2 The two books on plants {Tcpl (pvrQv) are frequently referred to by
Aristotle (468a 31, 4676 4, 656a 3, 7836 20) and are mentioned in the
catalogue of Diogenes Laertius, but were apparently lost as early as the
time of Alexander Aphrodisiensis (Jlo7\ circa 220 a.d.); cf. Zeller,
Aristotle, Eng. tr. Vol. L p. 91.

CHAPTEli V.

In like manner one must also treat of smell. For the
same effect which is produced by the dry or the moist, is
produced in another connection by savoury moisture in
air and water equally. Now we observe that the
diaphanous is a common principle in these two elements ;
the element, however, is not odoriferous by virtue of its
being diaphanous, but by virtue of its capacity to exude 443 a
and throw off dry savour. For smell is exercised not
only in the air but also in water. This is evidently so
in the case of fishes and mollusks ^ ; for these are known 2
to be endowed with smell although there is no air

^ The Testacea (6(rrpa>c65ep/ia), as used by Aristotle, include the
Mollusca (in the modern meaning), excepting the Cephalopods. They
include also the Ascidians and Echini, although these are sometimes
grouped by Aristotle amongst the Zoophytes. The Testacea form the
lowest group in the animal scale, lacking as they do the power of
locomotion and the higher senses, as sight and hearing. The Mollusca
{fxaXcLKLa) correspond to the modern Cephalopods, and the Crustacea
{/xaXaKdarpaKa) include the crabs, crayfish, lobster, etc., which have a
soft interior and a shell-like exterior, the shell being, however, flexible
and not brittle as in the case of the Testacea. These three classes
and the Insecta {evTo/Ma) form Aristotle's four classes of bloodless
animals. Cf. Ogle's Aristotle on the Parts of Animals, pp. xxix, 222;
Meyer's Aristotele>i Thierkunde, pp. 159 ff.

171

172 Aristotle's psychology desensu

in the water (for the air comes to the surface when
found in water) and they have no respiration. If one
assumes that both air and water are moist elements,
smell would be the dry sapidity in the moist and such

3 would be the nature of an odoriferous body. That this
condition in an object is derived from a sapid element is
a plain conclusion from things that do and do not emit
smell. For the simple elements, such as fire, air, earth,
and water, are non-odorous because the moist and dry in
them are non-sapid, excepting when a combination is

4 produced. This is why even the sea has a smell ; it
contains a sapid dry element. Salts are more odorous
than niti^e, as is proven by the oil derived from them.
Nitre, in turn, is more odorous than earth. Further, a
stone is inodorous, for it is without sapidity ; woods, on
the other hand, are odorous, for they are sapid, and
amongst woods those that are watery are less odorous.

5 Further, amongst metals gold is inodorous, for it is not
sapid ; bronze, however, and iron are odorous. When
the moist element is burned out of metals, the slag
becomes still less odorous. Silver and tin are more
odorous than some and less odorous than other metals ;

6 for they contain moisture. Some writers regard smell as
a smoke-like exhalation which is common to earth and
air [and all the naturalists fall back on this explanation
of smell]. And so Heraclitus made the remark that if

7 all things were smoke, we should discern everything by
our nostrils. Now, the naturalists all explain smell on
this theory, some of them describing it as vapour, others
as an exhalation, and others as a combination of both of
these. Vapour is a kind of moisture, whereas a smoke-

(MiAi-. V. NA TURK OK SMKM. 173

liko oxliiilation is, its we have said, coiiiinoii to air ami
earth. Water is (l(Miv(»(l I'nuii vapour, and a sort of
eartli is diivolopod from Hiiioke-like exhalation. lUit
neither of these two seems to be the odorous. For vapour 8
is due to water, wln'le smoke-like exhalation cannot possibly
be generated in wat(»r. And yet creatures that live in
the water have the sense of smell, as was said above.
Again, exhalations here have the same meaning as emana- 443/'
tions, and if the emanation theory was wrong, so is this
wrong. It is clear that the moisture which is found in 9
the air (for the air also has a moist character) and in water
is capable of deriving something from the sapid dry element
and of being affected by it. Furthermore, if the dry
element, when saturated, as it were, acts in moisture in
the same way as it does in air, smells must evidently
correspond to tastes. But precisely this fact is found in 10
certain flavours and savours. For there are pungent,
sweet, harsh, astringent, oily smells, and one might say
that rancid odours correspond to bitter tastes. 4s the
former, therefore, are revolting to the taste, so rancid
tastes are revolting to the smell. Evidently, then, that
quality which in water is flavour, in air and water is
smell. This explains why cold and frost blunt flavours u
and obscure smells. For cold and frost nullify heat,
which is the moving and active principle here.

There are two sorts ^ of odorous objects; for it is
untrue that there are no varieties of odorous objects, as
some maintain. Such varieties do exist. One must,
however, explain in what sense this is true and in what 12
sense not true. One variety corresponds, as clearly

^ The agreeable and disagreeable.

174 Aristotle's psychology desensu

explained, to flavour, and contains the pleasurable and
painful accidentally. For owing to the fact that these
smells concern our nutritive power, they are agreeable to
those who have desire and disagreeable to those who are
sated and feel no desire. Neither is the smell agreeable to
those to whom the food which has the smell is disagreeable.

13 Consequently, these smells contain, as we said, the pleasant
and painful accidentally, and this is the reason why they
are common to all animals. There is another variety of
smells which are pleasant in themselves, e.g. the fragrance
of flowers. For they incite us in no respect, whether more
or less, to food, nor do they in any way contribute to the
stirring of any desire ; they have rather the opposite
effect. What Strattis ^ says, mocking Euripides, is true :

When lentil-soup you cook,
Pray, add no spices to it.

444 a By mixing such spices in their potations, men now-a-days

14 force pleasure, as is their habit, believing that the
pleasure which is really derived from two sensations^ is

15 derived from only one. Smell of this sort is peculiar to
man, but smell that is based on flavour is sensed by
other animals,^ as remarked above. The varieties of the

1 Strattis, of Athens, the comedian ijlor. 410 B.C.). Cf. Meinecke,
Fragm. Com. Graec. p. 436.

2 The pleasures of eating and drinking are combined from smell and
taste.

^ The qualities of smell are few and inexact, because of the lack of
development of this sense in man {De an. 421a 10). Man possesses
the most delicate sense of touch and the worst sense of sniell. In the
lower animals smell is merely a handmaid of touch, while in man it
not only serves in this capacity but interprets the odoriferous world as
pleasant and unpleasant per se, i.e. apart from its association with
flavour.

«IIAI'. V.

KUNCriON OK SMKLI. 175

latter, bccauHc the i)lcuHant is incidental, are clasHified in
terms oi" ilavourH, which does not apply to the former
class, because there the smell is pleasant or disaf,'reeable in
itself. The reason why this class of smells is peculiar
to man is because of the condition of his brain. For lO
man's brain is by nature cool, and the bl(K)d in its
surrounding veins is thin and pure, though easily chilled
(which explains why the evaporation of food when cooled
in this region causes catarrhal colds), and so this variety
of smell has been developed in man as beneficial to his
health.^ For no other function can be ascribed to this
class of smells, although this function is evidently 17
exercised by them. Food, whether solid or liquid,
although agreeable, is often harmful ; but the smell
exhaled from savoury food indicates, one may say, what is
absolutely and always beneficial to man in whatsoever 18
condition he is. Consequently, smell is mediated by
respiration, not in all animals, but in man, the quad-
rupeds and such other sanguineous animals as have a
larger share in the employment of air. For smells being
transmitted to the brain by virtue of the levity of the
heat in them, the regions about the brain are thereby
the more healthy. For the potency of smell is naturally
warm. '''Nature employs respiration for two purposes ; 19
its main purpose is to assist the functioning of the
chest ; its secondary function is to transmit smell. For
in respiration the air produces, as it were in passage,
motion in the nostrils.^"''' Smell of this sort is peculiar to 20

^ Owing to their warm, dry nature.

2 This sentence is out of connection with the following one, and the
passage enclosed in asterisks should probably be inserted at the markt

4446 7.

176 Aristotle's psychology desensu

human nature, for man has, in proportion to his size,
the largest and moistest brain of all animals. For this
reason man is the only animal, one may say, that senses
the smell of flowers and similar smells, and finds pleasure
in them. For the warmth and movement in these
444'^ smells is proportional to the excess of moisture and
coolness in the brain. To the other animals that are

21 endowed with lungs for respiration, nature has given the
perception of another kind of smell, so as to avoid the
creation of two sense-organs. It is enough for these
respiring animals that they have the sensation of only
one class of smells, while man discriminates both

22 classes. tThat the non-respiring animals possess the
sense of smell is evident. For fishes and all the varieties
of insects, on account of the connection between food and
smell, distinguish smells with precision and at a distance,
as we observe in the case of bees and that variety of
small ants sometimes called cnips ^ and purple sea-fish,
as well as in the case of many other similar animals which
have a keen sense of smell for food. The organ of sensation

23 is not so clearly defined. One might, therefore, raise the
question as to the organ of the sense of smell, although
smell is mediated exclusively by respiration (this is
plainly so in all respiring animals). None of the above-
mentioned animals, however, respire, and yet they
perceive smells, unless we are to assume an additional

^ The term * Cnips ' has come into use in Zoology to describe a beetle
allied to the Cryptarcha (cf. E. Reitter, Verh. Ver., Briinn, xii. 1873,
p. 163). The reference here, however, appears to be to some small
variety of ant such as the formica Jf.ava, or to the common red ant
{monomorium pharaonis, cf. Comstock, Manual for the Study of InsectSf
p. 643).

CHAP. V. SMia.L ANf> RKSPIKATION 177

sense beyond tlio livo, and this is inii)08Hii)le. For it is 24
smell that senses the odorous, and th(*se animals d(;tcct
odour, though perhiips not in the same way as respiring
animals. In respiring animals the breath lifts up a
superficial membrane, a sort of cover, as it were (for
which reason they do not smell without respiration),
whereas in the non-respiring animals^ this is lacking, just
as over the eyes some animals have eyelids and without
lifting these do not see, while others are hard-eyed and
have no lids, and so do not need to lift any covering, but
see at once from the moment they are able to see. And 25
so, too, no other animal feels discomfort from a smell
which is intrinsically malodorous, unless it chances to
be harmful. But by these harmful smells animals are
sometimes destroyed, just as men often get a headache
from coal-gas and frequently lose their lives. In the
same way other animals are destroyed by sulphur and
asphalt fumes, and because they are so affected by such 445 ^
fumes they avoid them. But for malodour, as such, they 26
take no thought (although many vegetables have bad
smells), excepting in so far as taste or food is influenced 27
by it.

Inasmuch as the number of the senses is uneven, and
every uneven number has a middle term, it seems that
smell occupies a middle position between the senses that

^ In aquatic animals gills perform a function analogous to the lungs
in respiring animals. A similar function is performed in insects by the
membrane at the junction of abdomen and trunk (De resp. 4786 15,
475a 8). The gills iu fishes and the membrane in insects do not, how-
ever, appear to mediate smell, as the lungs do in respiring animals.
Owing to the semi-tangible nature of odour, it appears to act directly in
these cases, i.e. by impinging immediately on the sense-organ without
the assistance of inhalation.

M

178 Aristotle's psychology desensu

operate by direct contact, viz. touch and taste on the one

28 hand, and those which function indirectly through a
medium, viz. sight and hearing on the other hand.
Consequently, the odorous object is something which
affects foods (for these fall under the category of the
tangible), and, further, it affects audition, because smells
are sensed in the media of air and water. Smell,
then, is in a way common to these two things, and is
found in the tangible, the audible, and the diaphanous.
It is with good reason, therefore, that smell has been
compared to the imbruing and washing of a dry element

29 found in the moist and liquid. Eegarding the sense in
which one may or may not apply the term ' species ' to
odours, let the foregoing discussion sufiice.

There is a view held by certain Pythagoreans, which is
ill-founded. They hold that certain animals feed on

30 smells. Now we observe, in the first place, that food is
a composite thing, for the creatures which are nourished
are not simple, and consequently there is an excrement of
food, sometimes within the animal itself, and sometimes
external, as in the case of plants. Further, water when
taken alone and unmixed is not fitted to yield nourish-
ment, for what is assimilated into the body must be of a
solid nature. Again, it is much less reasonable that air

31 can become solid matter. In addition to this, we observe
that all animals have a receptacle for food, from which
after its entrance the body assimilates it. The sense-
organ, however, is situated in the head, and smell enters
with a breath-like inhalation, so that it penetrates to the

32 respiratory region. That smell, as such, does not contri-
bute to nourishment, is plain. That it does, however,

€HAP. V. HMKLL AND NUTRITION 179

contributo to hoalLli, is twidont from th(; senHatioii itHclf
and from what has boon .said/ so that what flavour is to
the nutritive organ and to the parts nourished, this smoll
is to health. Let these, then, be our conclusions regard- 445*
ing the several sense-organs.

^ Namely from its association witli food and from the effect of
inhaled warmth on tho head.

CHAPTER VI.

One might raise the question whether, supposing all
bodies to be infinitely divisible, the sensible qualities of
bodies are also infinitely divisible, such qualities as colour,
flavour, smell, sound, weight, cold, heat, lightness, rough-
ness, and softness. Or must we say that this is impos-
sible ? For every one of these qualities produces
sensation. They all receive their name from their

2 capacity to stimulate sensation. Therefore sensation
must be infinitely divisible, and every magnitude must be
sensible. For it is impossible to perceive a white object
without its having dimensions. Were this not true, it
would be possible to have a body without colour or
weight or any similar quality, in which case it would be

3 absolutely imperceptible, for these qualities constitute
the sensible. The sensible then would have to be com-
posed of the non-sensible. But it must be composed of
sensible qualities, for it cannot be composed of mathe-
matical elements. And, furthermore, what organ could
we use for the discrimination and co2:nition of such
elements ? Could we employ reason ? But they are not
rational elements, neither does reason think the external

180

DE 8ENSU

SKNSK AND MACiNlTUDK 181

world, exceptin«^ in conjunction with senHation.^ At the
same time, if this view of the infinite divisihility of sensihle
([ualities were true, it would appear to furnish support for
tlie advocates of atomic magnitudes. For iu this way the 4
problem would be solved. It is, however, impossible.
This subject lias been discussed in our treatise On Motion?
In the solution of these questions one will see why it is
that the various forms of colour, flavour, sound, and other
sensible qualities, are determinate. For in things that
have extremes, the internal properties must also be
determinate. The opposite is an extreme. Now, every 5
sensible quality implies opposition, e.g. in colours, white and
black ; in flavour, sweet and bitter. And in everything
else the opposites form extremes. The continuous is there-
fore divisible^ into infinite unequal parts, but into deter-
minate equal parts. Now, whatever is not in its own nature
continuous is divisible into determinate forms. Inasmuch 6
as qualities must be interpreted as forms, and inasmuch
as continuity is always given in these, we must suppose
a difference between the potential and actual. This is
why the ten thousandth part of a visible grain of millet
is unseen, although the eye rests upon it, and so too a 446^
quarter tone is undetected by hearing, although the whole

^ Reason thinks the external world only in terms of images, which
are derived from sensation {De an. 432a 8).

■•2 The reference is to the last three books of the Physics, which are often
referred to by Aristotle as irepl Kivqaeu)^ (cf. 272a 30, 299a 10, 318a 3,
10496 36). The particular reference here is to the discussion of
* continuity ' and * divisibility' in Physics, 213a 21 ff.

2 All magnitudes are infinitely divisible {Phys. 206a 10 ff.), and all
number is capable of being infinitely increased. Although magnitudes
are infinitely divisible, their infinity is only potential. The infinitely
small particle has only a notional existence.

182 Aristotle's psychology desensu

7 continuous melody is heard. But the interval from
mean to extreme is not appreciable to us. And the same
thing applies to the excessively small amongst other
sensible objects. They are discernible potentially, but not
actually, and when regarded in isolation. A foot-line is
contained in a two-foot line potentially, but actually only

8 after division has been made. When excessively small
parts like these are separated off, it is reasonable to
suppose that they would be lost in their environment,

9 just as a tiny particle of flavour is lost in the sea.
Nevertheless, since this excessively small particle, when
regarded in itself and in isolation, is imperceptible (for the
excessively small has only a potential existence in a body
that is more discernible), neither is any sensible object of
this sort, in isolation, actually perceptible, and yet it is a
sensible object, because it is so potentially, and will be
actually so, when added on to something. We have now

10 explained that certain magnitudes and qualities are imper-
ceptible, and have stated the reason for this, and have
shown in what sense things are perceptible, and in what
sense they are not. When, however, inherent qualities
are so constituted in reference to themselves as to be
actually perceptible, and not merely so in conjunction
with an entire body, but also when regarded alone, then

11 colours, flavours, and sounds., must be numerically limited.

One might raise the question whether sensible objects
or the movements excited by sensible objects — whatever
be the way in which sensation is effected by their
activity — are first transmitted to a medium, as appears to
be the case with smell and sound. For a person
standing near by has an earlier perception of a smell,

CHAP. VI. MKDllJM Ol" SKNSATION IH.'J

and ji aoiiiid reiiclieH oiu? .sometiiiKi aflor a blow. Ts the 12
same thin^ true of tlu^ viHil)lo and of lij^lit ? According
to Empedocles sunli^dit is first transmitted to a medium
before it reaches the eye or the earth, and this seems to 13
be reasonable. For whatever is moved is moved from
one point to another, so that a certain time must elapse
in which motion from one point to another takes place.
But all time is divisible, and consequently there is a
moment when the ray is not yet visible, but is still in 446*
transit in the medium. Also if everything at the same 14
moment hears and has heard, and in a word perceives
and has perceived and there is no time process in
sensations, nevertheless they lack this process in the
same way ^ in which sound, after the blow has been
struck, has not yet reached the ear.^ The shifting of 15
letters also shows this plainly, because their movement
takes place in a medium. For people appear not to
have heard what was said because the air^ has shifted. Is
this true also of colour and light ? For it is not owing 16
to a particular condition that one thing sees and another
is seen, like two equivalent terms. For it would not
then have been necessary for either to be in a given
position. For when things are equivalent, nearness or
remoteness from each other makes no difference. It is 17
reasonable that succession in time should be found in
sound and smell, for like air and water, they are

^ Read ojjlo'lojs for 8/jhos.

2 The passage of time has taken place in the medium, although one
may not be conscious of it. Aristotle defines time as the measure or
number of motion {Physics, 219a 10 &; De coelo, 279a 14).

^ The letters have become shifted in the air or medium, so that one
hears a word wrongly.

184 Aristotle's psychology desensu

continuous, and yet their movement is divisible, and so it
sometimes happens that the nearest and most remote
persons perceive the same smell, and at other times this
is not the case.

18 Some persons find a difficulty also in the following.
It is impossible, some say, for different persons to hear,
see, or smell the same thing in the same way. For it is
impossible for several persons who are separate from
each other to hear and smell alike ; in that event the

19 unitary object of sensation would have to be separated
from itself. The primary stimulus, as a bell, frankincense,
or a fire, is perceived by all as numerically one and the
same, but in its peculiar qualities it is perceived with
numerical differences, though in its essential nature as
one and the same thing ; for which reason many persons
see, smell, or hear the same thing at the same time.
One is not concerned here, however, with bodies, but
with qualities and motion (otherwise we should not have
this phenomenon), which are impossible apart from body.

20 The question of light is different ; for light has a sub-
stantial nature and is not a motion ^ ; in general the
same determinations are not to be applied to trans-
formation and motion. Spatial motions take place, as
one might suppose, first into a medium (sound is thought
to be the motion of something subject to spatial change),

447 <7 whereas that which undergoes transformation does so in
a way different from spatial change. It is possible that
transformation takes place in mass and not first by

^ Empedocles had described light aa motion (cf. De an. 418ft 20).
Aristotle on the other hand regards it as a qualitative change in the
diaphanous. It, therefore, represents a condition in a physical body
(air or water), vid. note 1, p. 159.

ciiAi. VI. MKDIUM i)V SKNSATION 1H5

halves, n.s in i\w. case of wat(;r which freezes at once 21
entire. Nevertlieless, if what i.s Ikmhj^' liealcd or frozen
sliouhl b(^ of consicU'rablo bulk, (►ne [)art i.s aHecled \>y the
adjacent part, and the firHt part undergoes chanj^cH
through its own alteration, and it is not necessary that
the entire mass undergo alteration at the same time.
Taste would also be subject to the same conditions as 22
smell, if we lived in a medium of water and perceived
smells from a distance without contact. When we have
a medium for the sense-organ, it is reasonable to suppose
we do not receive all our impressions at once, excepting
in the instance of light, on grounds already mentioned.
And sight is also excepted on the same grounds, for light
is the cause of sight.

CHAPTER VII.

Another similar problem touching sensation arises here,
viz. whether or not it is possible to experience two
sensations at one and the same moment of time, supposing
it to be true that the stronger stimulus always displaces
the weaker. For this reason, persons do not see an object
that falls upon the eye, if they chance to be deep in thought,
or exercised by fear, or listening to a loud sound. Let

2 this serve as a fundamental truth and let us also observe
that it is easier to perceive what is simple than what is
mixed, e.g. it is easier to taste unmixed wine than mixed,,
and so with honey and colour, and it is easier to dis-
tinguish the highest note when taken alone than when
heard in accord with the octave, because the two things

3 obscure each other. This occurs in cases where a unity is

produced from several elements. If, then, the stronger

displaces the weaker stimulus, it must happen, in case

they are simultaneous, that even the stronger stimulus

becomes weaker than it would be if it were perceived

alone. For the weaker when mixed with it detracts

from its clearness, supposing it to be true that every-

186

DEHKNHU FUSION OK SKNSATIONS 187

tiling takoii simply is more accurately percciptihle, 11
the two are ecjual neither one will he porcoive(i, for tlu^y
will counteract each other equally. IJut it is inipossihle 4
to have a simple sensation. Consequently, we shall have
either no sensation at all or a new one fused out of hoth
elements. And this appears to he what actually happens
with mixed elements, so long as they are mixed. Since s
a fusion of certain things is possible and of others not,
the latter are such as fall within the province of different
senses. (For wliere extremes are opposite, fusion is
possible, but it is not possible to form white and acute 447^
into a unity, excepting in an accidental sense, not how-
ever in the sense in which a union between acute and
grave is possible.) It is, then, impossible to have a
simultaneous sensation of these qualities. For the 6
stimuli being equal destroy each other, since a unitary
stimulus is not derivable from them. If, however, they
are unequal, the stronger stimulus produces the sensation ;
for the soul more readily perceives two stimuli simul-
taneously when only one sense is concerned in the single
act of sensation, as e.g. acute and grave. For simul-
taneous sensation on the part of a single sense is more
easily attained than is the action of two senses, such as
sight and hearing. But it is not possible to perceive 7
two things simultaneously with one sense unless they
are fused. For the fusion will form a unity and a single
sense can perceive a single thing and the single sensation
is a chronological unit. So then one necessarily
perceives fused stimuli simultaneously, because they are
perceived by a sense-process which in actuality is single.
The single sense in actuality perceives a numerically

188 Aristotle's psychology desensu

single object ; the single sense in potentiality perceives
a specifically single object.-^ If the sensation, therefore,
is in actuality single, it will interpret the sense-object

8 as a single thing. The sensations must then be
fused. When they are not fused, the sensations will
be in actuality two. However, there must be a single
actuality which corresponds to a single potentiality
and a single moment of time; for the stimulation and
exercise of a single sense is once for all single and its
potentiality is single. It is consequently impossible to

9 perceive two objects at one time with a single sense.
But if two objects that fall under a single sense cannot
be perceived simultaneously, this is plainly much less
possible when they fall under two senses, as e.g. white and
sweet.^ For the soul seems to denote what is numerically
one not otherwise than in terms of simultaneity; the
specifically one in terms of the discriminating sense and

10 the character of the thing. By this I mean that white
and black, which are specifically different, are supposedly
discriminated by the same sense ; also sweet and bitter
are discriminated by the same sense, although a different
sense from the former one. On the other hand, the
method of perceiving opposites is different, while co-
ordinated pairs are perceived in the self-same manner, e.g.
just as taste perceives the sweet, so sight perceives the

^ Actual sensation concerns only a given quality, e.g. white ; potential
sensation, on the other hand, concerns a given kind of quality, e.g.
colour.

2 Aristotle concludes that the only way in which several sensations
nnay be simultaneously experienced is by their fusion. By the process
of fusion, however, they are reduced to unity and the sense experience
is no longer manifold but unitary.

CHAP. VII. CO-ORI)INATK SKNSATIONS 1 HO

white ; as Ihv. sense of si^^lit perceives the blaek, so the
former sense perceives bitter. Further, if the sense- 448 «
processes of opposites are opposite to each other, and if it n
is hnpossible for opposites to coexist in the same in-
divisible thin<j;, then v^^here opposites fall under a sin^de
sense, as e.(/. sweet and bitter, they cannot be perceived
simultaneously. And similarly it can be proven that 12
things which are not opposites cannot be simultaneously
perceived, for some colours partake of white and others
of black and this applies equally to other sensations, e.g.
amongst flavours certain ones have the character of sweet
and others of bitter. Neither can fused objects be
simultaneously perceived, for their ratios have the
character of contrariety, e.g. the octave and the fifth,
unless they are perceived as one. In this way and not 13
otherwise a single ratio of extremes is produced. For in
any other case there will be produced at once the ratio
of the many to the few, and of the uneven to the even,
and on the other hand the ratio of the few to the many,
and of the even to the uneven. If co-ordinates which 14
are specifically different, are further removed from each
other and differ more than things that are specifically the
same {e.g. sweet and white I mention as co-ordinates, but
specifically different), and sweet differs from black more
than white does, it would be still less possible for these
opposites to be perceived simultaneously than it would
be for opposites specifically the same. So that if the 15
latter are not simultaneously perceptible, neither would
the former be.

In regard to the opinion of certain writers who treat
the subject of harmony, and say that sounds do not

190 Aristotle's psychology desensu

really reach us at the same moment, but only appear to
do so and we do not notice this, the time being imper-
ceptible, the question is whether their opinion is right or
i6 not. Here, also, one might perhaps say that we only
appear to hear and see at the same time, because the
intervening time is not perceived. This is incorrect ;
it is impossible for time to be imperceptible, or for us to
be unconscious of it, but every moment is perceptible.^

17 For when one perceives one's self or something else in
continuous time, it is impossible for one to be then
unconscious that one is ; but if there is in continuous
time a moment of such duration that it is altogether
imperceptible, it is evident that one would then be
unconscious of one's own existence, or would not
know whether or not one sees and perceives. Further,

448^ even if one has perception, time would not exist and
there would be no object nor any moment in which
sensation should take place, unless it were in the sense
that one sees in a part of time or a part of the object, if
there is a measure of time or object, which, owing to its
smallness, is totally imperceptible. For if one sees the
entire earth, one also perceives time itself in its
continuity, and not in any of its isolated moments. Let

18 C B represent a time-division in which one has no
perception. One sees, then, in a particular part of the
whole or sees a particular part, just as one sees the
entire earth, viz. by seeing a definite part of it, and how
far one walks in a year, viz. by seeing how far one
walks in a definite part of a year. But in the division
B C there is no perception. Now, by virtue of

^ On the ' minimum visible ' see Lewes, Aristotle, p. 253.

€HAP. VII.

RTMULTANRITY 101

perceiving tho whole A 11 in Home dotinite pjirt of it,
one is said to percuiivo even the entire earth. And i9
the same reasoning; holds j^ood of A C. For one always
perceives in a part and a ])art, and it is impossible
to perceive the entirety. And so every thing is per-
ceptible, but one does not see what its extent is.
For one sees the magnitude of the sun and of the
four-cubit measure from a distance ; they are not
seen, however, in their real size, but sometimes they
seem indivisible, and one does not see the indivisible.
The reason for this has been stated in the foregoing. 20
One concludes from this that there is no imperceptible
time.^

We must take into consideration the above-mentioned
problem, whether or not it is possible to have several
simultaneous sensations. By 'simultaneous' I mean such
as are experienced in the same part of the soul and in
one indivisible moment of time. In the first place, then, 21
is it possible that the sensations be simultaneous in the
sense that they are experienced in different parts of
the soul, and not in one indivisible part, though by
parts which are indivisible in the sense of forming a
continuous whole ? Or, to take first what affects the
single sense, as e.g. sight, shall we say that if different
colours are sensed by different parts of sight, it will
then have several parts specifically the same ? For its
repeated sensations belong to the same species. But 22

^ Aristotle defines time (note 2, p. 183) as the measure or number of
motion, but time cannot exist apart from mind, as number cannot exist
apart from a calculator, and the sole calculator is mind {Phys. 223a
16 ff.).

2 Read Tavrd (supported by most of the mss. ) for TaOra.

192 Aristotle's psychology desensu

if one says that, as in the instance of our two eyes,
a certain unity and single activity is produced, so
nothing prevents our regarding the soul in the same
way. If, however, the combination of both forms an unit,
then that which is perceived will be an unit, and if they
remain uncombined, then the result will likewise be

23 uncombined. Again, the same sensations will be mani-
fold, in the sense in which one speaks of sciences as

449 a manifold. For neither is there any actuality apart
from its corresponding potentiality, nor is there any
sensation apart from actuality. If one does not experi-
ence simultaneously the sensations which occur in a
single indivisible part of the soul, it is clear that one does
not experience others simultaneously For it is simpler
to perceive these several things simultaneously than it is
to perceive generically different things simultaneously.

24 But if the soul senses sweet with one part and white
with another part, the derivative of these two is either an
unit or it is not an unit. But it must be an unit, for
the perceiving organ is an unit. What is the unit, then,
with which this organ is concerned ? For we have no
unit from sweet and white. There must, therefore, be
some unitary principle in the soul, whereby it perceives
things as wholes,^ as remarked above, but things generic-
ally different are sensed by different organs. Is then

25 the principle whereby we perceive sweet and white a
single organ, in so far as these qualities are united,
but when they are actually isolated, is it a different

^This function is ascribed to the 'common sense,' where the various
experiences of the individual senses are fused into a whole or the
percept. Cf. Introdiiction, Chap. iv.

oiur. VII. LIMITS OF PKRCKmON 103

or<j;an tlmt s(mi.s(»m (micIi of tlniiii i Wluil applieH to
the tliint^H (1hmii,so1v(*.s, a]>|)lios Rimilarly to tho houI.
lM)r numoric'.ally one and tho same \\\\\\^ is whito and
swet^t, and ])()8seHseH many otiier qualities, unless the
qualities be regarded as isolated from one anotlier, and
yet the essential nature of each ([uality is different. On(i
must likewise conclude in reference to the soul that on(? 26
and the same principle (numerically regarded) perceives
everything, although its mode of expression is different,
in some cases generically different, and in others
specifically different. Simultaneous sensations, therefore,
are experienced in one and the same principle of the
soul, but not in one and the same relation to this
principle.

It is evident that every sensible object has a certain
magnitude, and that it is impossible to perceive what
is indivisible. There is a point from which it is im- 27
possible for one to see, viz. a point of infinite removal,
but the point from which vision is possible is deter-
minate. The same applies to the odorous and audible
and to such sensations as are not tactual. There is an
extreme point of remoteness from which vision is no
longer possible, and a point of nearness at which vision
begins. This point must be indivisible, and what is 28
beyond it is not perceptible, and what is on this side
of it must be perceptible. If, indeed, an indivisible
thing is perceptible, then it will follow when one places
it at the extreme point from which it is no longer
visible, and again at the point where perception begins,
that it is simultaneously visible and invisible. And this
is impossible.

N

194 Aristotle's psychology desensu

449 b We ^ have now treated, in general and in particular,
the subject of the organs and objects of sensation. In
what remains, we must first investigate the subject of
memory and of memory's process.

^ Bekker in the editions of Berlin (quarto) and of Oxford (octavo)
transfers this paragraph to the beginning of the tractate On Memory.
For a critical examination of the arrangement of the text vid.
Freudenthal in Ehein. Mvsenm, Vol. 24, p. 393.

ON MEMORY AND RECOLLECTION.

CHAPTER I.

In regard to memory and its process, we must determine
what its nature is, by what agency it is produced, and to
what psychical organ the phenomenon of memory, as
well as that of recollection, is to be ascribed. For

^Aristotle makes the following distinction between memory {fxurjfir))
and recoUectiou {dvdiji.ur](ni) : the former is the reproduction of a past
experience accompanied by the consciousness that the experience has been
previously had ; the latter is the deliberate reproduction of the same
experience and is based on reflection. The former is possessed by the
lower animals and the latter by man only. Plato had already made a
distinction between memory and recollection [Phaedo, 7.3 B ff.,
Philebiis, 34 B). The passive presence of residual sensations in the soul
is memory, while their active recall to consciousness is recollection. In
the Meno the whole of knowledge is resolved into recollection or
reminiscence [dvdinvrjcri^), learning being only the stimulation or revival
of knowledge congeuitally in us. In a note which Grote meant to be
added (directions to this effect are recorded in the MS.) to Chap. XX.
of his Plato and the Other Companions of SoJcrates, he says: "The
doctrine of Reminiscence declared and illustrated by Sokrates in the
Platonic Menon [Trdaa ixdOrjai^ dvafivrjo-cs) bears much analogy to the
Development-Hypothesis espoused by Mr. Herbert Spencer ; an extension
and special application of the large views opened by Mr. Darwin respect-
ing the origin of species. Each individual animal is assumed to begin

195

196 Aristotle's psychology de mem.

the same persons are not endowed with good memory
and good recollection, but as a rule phlegmatic natures
remember well, while the quick and ready-witted are

2 apt at recollection.

First of all we must grasp what is understood by the
object of memory. For one is often mistaken about this.
The future cannot be the object of memory ; this is
rather the object of conjecture and expectation (and we
might even have a science of expectation, as some
describe the subject of prophecy). Neither can the
present be its subject-matter, for our senses are concerned
with this. By sensation we do not have cognizance
either of the future or of the past, but only of the

3 present. Memory, on the other hand, regards the past.
No person would say that he remembers the present
while ^ it is present, e.g, that he remembers seeing the
white object while he sees it ; neither does one remember
the object of contemplation, so long as the act of con-
templation and thought continues. But one merely says
that in the former case one sees, and, in the latter, one
knows. When, however, one possesses knowledge or sen-
sation which is not in actuality, then one remembers that
the angles of a triangle are equal to two right angles,
because one has learned it or thought it out, or, on the other

existence with a large stock of congenital predispositions and aptitudes
engrained in its nervous system as the result of an * infinitude of past
experiences ' — not indeed of its own but of its progenitors. Hence arise
all its instincts, and many of its mental combinations which go beyond
instinct. See Mr. Spencer's Psychology, pp. 577-583-619." Extract
from the Mss. of **Grote's Papers" in the Bodleian Library, Oxford
(MS. add. D. 85, p. 37).

^ Read 'dre for 6tl.

<iiiAi'. I. MKMOKV ANI> TIMK 107

hand, has moroly hoard it or viHually ohscrvod it, or found
it out in some sucIj Wiiy. For when nu'uiory actually takes
place, ono must say that tlio process in the soul is such
that one foiiiierly heard, perceived, or thought the thing.
Consequently, memory is neither sensation nor conceptual 4
thought, but it is the condition or modified form of one
of these, after the lapse of time. There is no memory of
the present in the present moment, as we have said, but
there is perception of the present, expectation of the
future, and memory of the past. Consequently, all
memory is associated with time. Therefore, only those
creatures that have perception of time, have memory,
and memory attaches to that organ whereby time
is perceived.^ Now we have already discussed imagin- 5
ation in the treatise On the Soul^ and we concluded
there that thought is impossible without an image. For
we find in thought the same conditions as in drawing 450 a
figures. In the latter without needing a triangle of a
definite magnitude, we nevertheless draw a triangle of
definite size. So, too, the thinking mind, even if it does
not think a magnitude, still places a quantitative body
before its eyes, although it does not think it as such. If 6
it is the nature of the quantitative in an indefinite sense
with which the mind is concerned, then thought represents
it under the form of a definite quantity, but thinks it
merely as quantity. The reason why it is impossible to
think anything apart from continuity (even things that
are not subject to the laws of time cannot be thought

^ The organ of memory and the organ whereby we perceive time is the
central organ or heart {451a 17).

2Cf. De an. 4276 14 ff. ; 434a ff.; 431a 17.

198 Aristotle's psychology demem.

without time ^) is a problem that belongs elsewhere.^
We must be conscious of magnitude and motion ^ by the
same faculty whereby we are conscious of time. An

7 image is a product of sensation in general. Evidently,
therefore, the cognition of these things is to be ascribed to
the primary power of sense. Memory, even the memory
of concepts, does not take place without an image.
Consequently, memory concerns the faculty of thought/
accidentally and the primary power of sense intrinsically.*
It is, therefore, possessed by other animals, and is not
peculiar to man and creatures endowed with opinion

8 and thought. If it were a property belonging to the
conceptual powers, it would not be found in many
animals outside of man, perhaps in none of the brutes,
seeing that they do not, as a matter of fact, possess
it because they all lack the sense of time. For in
an activity of memory, as we remarked before, there is
always the additional consciousness that one has seen or

9 heard or learned this in time past. Prior and later are
properties of time. In reply to the question to what part
of the soul memory is to be ascribed, it is plain that it
belongs to the same part as imagination. The objects of

^Aristotle is referring probably to the heavenly bodies and their
eternal laws.

2 Topics of this kind Aristotle refers to the First Philosophy or
Metaphysics.

^ Magnitude and motion are classified by Aristotle amongst the * com-
mon sensibles ' and as such they are perceived by the ' common sense '
whose organ is the heart.

^In other words memory is a revived sense-experience and is due to
the direct function of the primary organ of sense (the heart) ; it concerns
the faculty of thought only accidentally, viz. in furnishing it with
images which are converted into concepts that are essentially different
from images.

(JHAP. I. MKMORV IS A PICTURE 100

memory, iiitrinaically, arv tlu! same as Uu) ()])j(3ct3 of
imagination ; accidontally, iJioy aro such objects as are
impossible without imagination.^

The question might be asked: Tlow in the world is
it that while a mental impression persists, although the
thing itself is no longer at haml, one remembers what is
not present ? Evidently we must regard this phenomenon lo
which through the mediation of sensation is produced in
the soul and in that part of the body'"^ which possesses
sensation (whose persistence we call memory), as similar
to a painting. For an active stimulus stamps on the soul
a sort of imprint of the sensation, analogous to stamping
with a seal-ring. For this reason, too, persons who are u
deeply moved by passion or by the ardour of youth do 450^
not remember, just as if the effort and the seal were
applied to running water. In other persons, because of
their worn-out condition, like old buildings, or because
of the hardness of their receptive principle, no impression
is made. Consequently, the very young and the aged have 12
poor memories. For the former are in a fluent condition
owing to their growth, and the latter are unstable owing
to their decay.^ Likewise the excessively quick and the
excessively slow seem to have poor memories. The

^ When the objects of imagination are recognized as past experiences
or copies of past sensations they are called memories. They are, there-
fore, in their essential nature or intrinsically the same as the objects of
imagination. Objects of memory in an accidental sense are, perhaps,
such elements as do not attach to the image as such, but are not possible
without it, e.g. the circumstance that Coriscus (who is the image proper)
was a native of Scepsis.

2 Namely, in the heart.

3 It is this passage which Reid distorts in his review of Aristotle's
theory of memory. Cf. Works, ed. Hamilton, p. 353.

200 Aristotle's psychology demem.

former are too moist and the latter too hard. Con-
sequently, the image does not last in the souls of the

13 former, and in the latter it does not fasten. If such is
the truth regarding memory, the question arises whether
one remembers the impression or the thing from which
the impression was derived. For if it is this impression
of ours which is the object of memory, then we do not
remember what is absent. On the other hand, if it is
the thing that we remember, how does it come that while
we perceive this impression we remember what we do not
perceive, viz. the absent thing ?^ And if memory is
analogous to an imprint or picture within us, why should
the perception of precisely this thing be the memory of
something else, and not the memory of just this picture ?

14 For it is this impression which one contemplates and
perceives in actual memory. In what sense then does
one remember what is not present ? It would then be
possible to see and to hear what is not present. Or is
there a sense in which this is possible and in which it

15 actually occurs ? For example, the animal in a picture
is both animal and a copy, and both of these are one and
the same thing ; but the mode of existence in the two
instances is different, and it is possible to regard this
picture both in the sense of animal and in the sense of
image, and so it is with the image within us : we must
regard it both as something in itself and as the image of
something else. In so far as we regard it in its own

^ Aristotle explains further down (4506 30) that the image is not only
a thing in itself which we have actually in consciousness, but it is also
representative of the external and absent thing, which, though not in
consciousness, is thus mediately or representatively remembered.

CHAT. I. MKMOHY AND PHANTASM 201

nature, it is an idea or ii niciital representation ; in ho fai*
as we regard it as belonging to something else, it is a copy i6
or a memory. Wlien, therefore, an actual stimulation ol"
this image takes place, and when the soul perceives it in
its own nature, it appears to come to expression as an idea
or a phantasm; if however the soul regards it as belonging
to something else, then, as in the case of a painting, the
soul contemplates it as a copy and as the picture of
Coriscus, without having ever seen him. The points
of view here and in the case of our regarding a painted
animal merely as an animal are different : what arises in
the soul in the latter case is purely a thought ; in the ^S^a
former case, because the object is there regarded as an
image, it appears as a memory. And, consequently, there 17
are times when we do not know, regarding such psychical
processes due to earlier sensations, whether they are
produced by sense-experience, and we are in doubt
whether they are a memory or not.-^ At another time it
happens we think and recall that we have haard or
known the thing in the past. This takes place when 18
after contemplating a thing in its own nature, one shifts
one's position and regards it as the copy of another thing.
The converse of this also happens, as is shown by the
case of Antipheron of Oreos and other ecstatics. For they
asserted that their phantasms were real, and that they

^ It is often ditficult to decide whether certain apparent memories are
merely fictions of imagination or actual past experiences, because
imagination is not merely reproductive {aladrjTLKT}) but productive
{XoyicTTiKri). It is, however, impossible to have an unconscious memory.
So long as one is not conscious that a given experience or image has
been had before, the thing is only a phantasm {(pavracrfMa) and not a
memory {fiurj/jiSvev/ia). Cf. 4526 26.

202 Aristotle's psychology demem.

remembered the things. This phenomenon occurs when
19 one regards as a copy that which is not a copy. Exercise
in repeatedly recalling a thing strengthens the memory.
This, however, is nothing more nor less than the frequent
contemplation of a thing as a copy and not as an object in
itself. The nature of memory and of its process has now
been explained as the persistent possession of an image,
in the sense of a copy of the thing to which the image
refers, and it has been further explained to what faculty
in us this belongs, viz. to the primary power of sensation,
and to that organ whereby we perceive time.

CHAPTER II.

The subject of recollection remains to be treated. First
of all we must take as presuppositions the truths which
were established in the treatise On Argumentation}
Accordingly, recollection is neither the recovery nor 2
acquirement of a memory. For when one learns or
acquires an impression for the first time, one does not
recover any memory (for none has preceded), nor does
one acquire an initial memory. But when a persistent
mental condition and impression is fixed in the soul, then
we have memory. Consequently, memory is not produced
simultaneously with the production of an impression.
Further, in the indivisible complete moment when the 3
impression is first received, the impression and the know-
ledge are recorded in the affected subject, if one can call
this mental condition and impression, knowledge, (and

^Themistius and Michael Ephesius think the reference is to the
Problemata. Bonitz, however, considers it more probable that Aris-
totle is referring to the diropiaL discussed in Ch. I, of the present
tractate. Cf. Index to Bekker's Berlin edition sub. voc. 'ApLaroTiXrjs,
99a 38. If the latter supposition is correct, one will have to give the
words X6701 eTTLx^iptj/JixiTCKol the unusual meaning of Initial Treatise^
which, however, they might perhaps bear.

203

204 Aristotle's psychology demem.

there is nothing to prevent our remembering, in the sense
of accident, a certain thing which we know conceptually).
But memory as such is not possible until after the lapse of
time. For what we remember now, we have previously
known or experienced, but what we experience now is

4 not in the present moment remembered. Further, it is
451 b evidently possible to have in memory what we do not

now recollect, but what was once perceived or experienced.
When one re-acquires knowledge or sensation (or whatever
the mental possession be to which we apply the term
memory), it is then that one recollects one of the afore-

5 said mental possessions. The process of memory takes
place, and memory ensues. Neither do the phenomena
of recollection, if their occurrence is the repetition of a
previous recollection, follow absolutely the same order,
but sometimes they occur in one way and sometimes in
another.^ It is possible for the same individual to learn
and discover the same thing twice. Kecollection, then,
must differ from learning and discovery, and there is
need of greater initial latitude here than is the case with
learning.^

6 Recollection is effected, when one suggestion succeeds
another in natural order. If the succession is a necessary
one, it is plain that when the antecedent suggestion is
given, it will excite the succeeding one. If, however, the

^ A given association may at one time awaken a recollection and at
another time fail to do so (cf, 4526 1 flF.).

^ In the case of learning and discovery there is a definite and exact
process by which a given result may be twice arrived at. In the case
of recollection, on the other hand, there is not the same fixity of
procedure. There are not only many forms of suggestion and associa-
tion, but a given suggestion may not effect the same result in two
instances.

(,iiAi'. II. ASSO(JTATI()N OF IDKAS 20ri

Mucccasioii is not. ;i nccosaary one, l)ul only cuRLoinary, tlit*
recollection will Ik; stirred generally. liut it is a faet 7
that aoiue persona by bein;^' ini])res.se(l only once arc
trained ^ in a i^iven way more than others after frequent
impressions. And so there are some things which after
we have seen once, wo remember better tban others do
who have seen them fre(\uently. When, therefore, we
recollect, we awaken certain antecedent processes and
continue this until we call up tliat particular experience,
after which the desired one is wont to appear. That is 8
the reason why we hunt through a series in thought,
beginning with an object presently before us, or with
something else, or with an object that is similar, or
opposite, or contiguous.^ In this way, recollection is
awakened. For mental movements in these instances
are identical in some cases, in others simultaneous
with, the desired experience, and in other cases they
involve a portion of it, so that there is a small
remainder whose stimulation ensues. This uhen, is
the way in which people try to recollect, and without 9
conscious effort they recollect in this way, when
the desired experience is recalled as the sequence of
another experience. For the most part, however, the
desired experience is recalled only after several different
suggestions, such as we have described, have preceded.

^'Trained' (idLadTjvaL) means here the acquisition of a fixed habit
{^6os) or disposition. In the case of other persons, impressions do not
produce a fixed disposition, but are evanescent. Consequently in the
latter, a suggestion is inefi"ective, while it results in recollection in
those persons where the impression has become a fixity or 'habit.'

2 The laws of association, ordinarily treated as contiguity and
similarity, are here stated by Aristotle as similarity, contrast, and
contiguity.

206 ARISTOTLE S PSYCHOLOGY de mem.

One does not at all need to look at the remote and ask
how we remember it, but at what lies near before us.
For the same method applies to both cases, — I mean the
method of sequences,^ without any prior effort to find
this sequence and without recalling it. For mental

10 movements follow one another, this one after that,
by habituation. When a person wants to recall a thing,
he will do the following : he will try to gain a starting-
point in the process, in sequence to which the desired
experience was had. Consequently, recollections which
are awakened from the starting-point are most quickly

452 a and best effected. For just as things are mutually
related in their order of succession, so also are the

11 mental processes. And such things as have a fixed
order are easily remembered, as e.g. mathematical truths.
Other things are remembered poorly ^ and with difficulty.
EecoUection differs from re-learning in this, that there
can be in the former case a sort of self-movement back
to that which follows upon the original experience.
When this is not done, but the recollection is prompted

12 by another person, then it is no longer memory. Often-
times one is unable to recollect a thing, but after searching
succeeds in finding it. This seeking and finding is what
happens when one awakens a number of experiences and
continues to do so until one sets that particular experi-
ence in motion upon which the desired thing is attendant-
Memory is the possession of an experience potentially

^ This series of sequences is compared by Tliemistius to a chain, in
which if one link be lifted the next will likewise be moved and so on.
Cf. Sir William Hamilton's note in Keid's Works^ p. 894.

^ Read 0aiJXws Ka.1 for 0aOXa.

fiiAi'. 11. ASS()(JIATI()N Ol" IDKAS 'JOT

revivablc. 'I'his process is on'ectod, aH was said alxive, in
such way that it coiiios iVoni Ihv. ])crson's own cllort and
from the raovcnicnts in his power. One must, however, 13
have a starting-point. And so persons appear sometimes
to recall things from local ^ suggestions. The reason is
that one passes rapidly from one thing to another, e.rj.
from milk to the suggested idea of white, from white to
air, from air to the moist, and from this one recalls the
late autumn, which is the season one was trying to think
of. In general, it is the middle, too, of the entire series '4
that seems to be the starting-point for memory. For
when a person does not remember earlier, then he does so
when he comes to the middle point, or when he does not
remember here, then at no other point at all, as is the
case e.g. when one passes through the series ABCDEFGH^^
If one does not remember at H, one remembers
when one comes to E, provided one is in quest of F or G.
For from that point the movement of suggestion is
possible in both directions, towards the point D as well
as towards the point F^^ If, however, a person is not in 15
quest of one of these, he will remember on reaching 0, and

^ There is no reason for adopting the conjecture of Sir William
Hamilton (firoTra for airb Td-rroji/ 452a 13), which Barthelemy-Saint-Hilaire
(Commentary, ad loc.) considers necessary and which Hamilton charac-
terises as "absolutely certain" (Reid's Works, p. 905 note).

2 Freudeuthal {Rhein. Museum, xxiv. p. 410) thinks we have here a
defective text, because in a series of eight elements there is no middle
term. It seems, however, hopeless to get anything satisfactory out of
the illustration by emendation or reconstruction.

^ Vid. Freudenthal's explanation in the Archiv fur Geschichte der
Philosophie (vol. ii. p. 2) and Siebeck's in his Untersuchurifjen zur
Philos. der Griechen (2te Aufl. p. 155). Sir William Hamilton simply
distorts the text beyond recognition in order to obtain an intelligible
translation, and even then achieves but a meagre success in his aim.

208 ARISTOTLE S PSYCHOLOGY de mem.

if not then, he will remember on reaching A, and this is
the case always. But from the same point of suggestion
one sometimes remembers and sometimes does not, the
reason for which lies in the possibility of movement in
more than one direction from the initial point, e.g. from JiJ
i6 to F or from U to I). If the movement is influenced by
an old suggestion, it takes place in the direction of the
more fixed habit.^ For habit is second nature. Conse-
quently, we remember easily what we often ponder. For
as one definite thing succeeds another in nature, so it

17 is also in our activity. Frequent repetition produces
nature. Since we find in the realm of nature occurrences

452/; that violate her laws and are due to chance, much more
do we find this in the realm of custom, to which the
term nature cannot be applied in the same sense. The
consequence is that a movement here sometimes takes
place in one direction and sometimes in another, especially
when the mind is distracted from a particular point to

18 something else. Therefore, when one has to remember a
name, and remembers one like it, one commits a solecism
in regard to it. This then is the way in which recollec-
tion takes place. ^

The most important thing here is the necessity of
appreciating time, whether in a determinate or an in-

19 determinate form. There must be some power whereby
we distinguish a longer from a shorter interval. It is
natural that the same conditions which apply to magni-
tudes, apply here also. For we think what is large and
what is remote in space, not because thought extends to

1 Vid. Sully, The Human Mind, Vol. L p. 20L
^ Namely, through the association of ideas.

OIIAI'. II.

I'KOCIOSSKS OK MK.MOKV

209

the given point, as sonic say ^ in Llieir cxj)liination of
vision (for we can think the non-existent as well as the
existent), hut hecausci of an analogous process in the
mind. For the figures and processes that correspond to
things are in the mind itself. What difference will it 20
make, then, whether one thinks what is larger, or the other
class of things that are smaller ? For all the internal
elements are smaller, and the external have, as it were, a
proportional magnitude to them. It is perhaps in the
case of distances in space just as it is with figures, one
has to assume the possession of another analogous figure
in the mind itself. So, e.g. if one draws the lines ^j5and 21
BE, one produces CD, for AC and CD are proportional.
Why does this produce the line CD rather than FG ?
Or is this due to the fact that as AF is to AB, so H is to
J/? For these lines are drawn at the same time. And
if one wants to think the line FG, one thinks similarly
the line BE, and instead of HI one thinks KL. For
these are related to each other as FA to BA}

^ Empedoclea.

^ Freudenthal {Rhein. Museum, Vol.
24, p. 416) attempts to elucidate this
hopelessly difficult passage by the
figure :

In this figure Freudenthal makes AB,

BE represent sense-impressions ; AF^

FG external objects; AC, CD, notions

or concepts ; Mff, HI, time objectively

regarded ; 3fK, KL, time subjectively

regarded. Consequently, so he goes on

, . AB AC AF
to explain: -g^ = ^:^ = -^ means that

presentations of sense or images of
(pavTaala are related to each other as the

0

H

K

I

F
B

c /

//

/ / L

C

/ /

/

\ /

M

210 Aristotle's psychology demem.

22 When the suggestion of the thing and the suggestion of
time coincide, we have actual memory. When, however, one
believes one does this without really doing it, one only
believes that one remembers. For there is nothing to
prevent one's being deceived and fancying that one
remembers without this being actually the case. In
actually remembering it is impossible that one should
not believe one is remembering, but should be uncon-
3 scious of it. For this is just what constitutes memory.
If, however, the suggestion of the thing and the sug-
gestion of time are separated from each other, then no
memory is awakened. The suggestion of time has a two-
fold meaning. Sometimes a thing is not remembered
in determinate time, e.g. that day before yesterday one
453 a did something or other ; in other instances one remembers
in terms of time-measure. Memory, however, takes
place even if one does not remember in the latter way.

24 People are wont to say that they remember, although they
do not know just when a thing happened, in cases where
they are ignorant of the determinate measure of the
When.

We have already said that the same individuals are
not endowed with good memory and good recollection.

25 Eecollection differs from memory not merely in the time-
element, but also because many animals share the endow-
ment of memory, while none of the known animals, one

AB AF
corresponding notions. ~di:^— pjy signifies that presentations of sense

are related to each other and the corresponding external objects are re-

lated to each other. -7-^ = -t7 or -rrr^—-nr^ signifies that external objects
AB M BE KL ^ ""

are related to their sense-impressions as objective time to subjective

time.

cum: n. RK(^OLLK(rn()N 'J I 1

iiijiy sjiy, exco])tin^ iiiun, is oiidowtMl with rucollciclion.
Tlio reasun for this is that recolloction is a sort of Hylic- 26
gistic procoaa. In recolliiction one; reasona thai ono has
known or hwinl or had aonio such experience of the thing
in question, and the process is a sort of inquiry.^ And
this is naturally found only in those creatures which
have the power of deliberation, and deliberation is a kind
of syllogistic procedure.

That this condition affects the body, and that recollec- 27
tion is the search for an image in a corporeal organ ,^ is
proved by the fact that many persons are made very
restless when they cannot recall a thing, and when quite
inhibiting^ their thought, and no longer trying to remem-
ber, they do recollect nevertheless, as is especially true of
the melancholic. For such persons are most moved by
images. The reason why recollection does not lie within 28
our power is this : just as a person who has thrown an
object can no longer bring it to rest, so too one who recol-
lects and goes in search of a thing, sets a corporeal some-
thing in motion, in which the desired experience resides.
Especially disturbed are such persons as have moisture 29
about the region of sensation ; for they do not easily come
to rest after being stirred into motion, until they attain
the thing sought for, or the movement has taken its
proper course. Consequently, the feelings of anger and

^ In intentional recollection one employs the laws of association
deliberately and through reflection ; in spontaneous recollection the
same laws apply, but are not deliberately employed.

"^ In recollection the organic process is from within to the organs of
sense, while in sensation the process is from the periphery to the centre
(JDe an. 4086 17).

^Read, kuI ttolw eTrexovTas, 453a 17.

212 Aristotle's psychology demem.

fear, when they once set up a movement, do not cease
although opposing movements are started against them,

30 but on the contrary persist towards their own aim.
This affection resembles names, melodies, and words, when
these are given violent utterance. For after one has

31 ceased, the singing or speaking recurs involuntarily.
Further, those whose upper body is too large, and also

453 ^ dwarfish persons, have less power of recollection than those
of the opposite physical structure, because the former are
too heavy about the organs of sensation, and because the
initial movements cannot persist but are destroyed, and
direct movement in the process of recollection cannot

32 readily take place. Also the exceedingly young and the
very old do not recollect well on account of their move-
ment ; for the latter are in decline, and the former in
rapid growth. Furthermore, children are like dwarfs
until they advance in age.

We have now treated the subject of memory and its
process, its nature and the psychical organ whereby
animals remember ; also the subject of recollection, in its
nature, its forms, and its causes.

ON SLEEPING AND WAKING.

CHAPTER I.

We must now consider the subject of sleeping and
waking, and ask what they are and whether they are
phenomena peculiar to the soul or common to the body ^
and the soul, and if they are common, we must further
inquire to what particular organs of the soul and body
they belong. Further, we must inquire to what cause this
animal function is due and whether all animals share in
both sleeping and waking. Or are certain animals endowed
with the one, and others exclusively with the other, or
are there creatures that are endowed with neither of
them, and others with both ? In addition to this we must
investigate the nature of dreams and explain why persons
sometimes dream ^ in sleep and at other times do not.
Or shall we say that dreaming always occurs in sleep,

1 Aristotle had himself stated the mixed physiological and psychological
character of these opuscules in referring to their subject matter as kolvcl
rrji i^i'X^s /cat adofxaros (436a 7). See also note, 1, p. 145.

2 The subject of Dreams and Prophecy by Dreams is specially treated
in separate opuscules. Vid. pp. 231 ff., 247 ff.

213

214 Aristotle's psychology de somno

but we do not remember our dreams ? If this is true,
what is the explanation ? A further question is whether
or not it is possible to foresee future events, and if it is
possible, in what sense are they foreseen ? Further, is it
possible to foresee only such future events as are per-
formed by man or also such as are caused by divine
power, and does this foresight apply to what takes place
in the course of nature or to the results of accident ?

2 First of all it is evident that both sleeping and waking
are to be ascribed to the same organ, for they are contrary
functions, and sleep is clearly the negative of waking.
Now contraries, whether in the realm of nature or else-
where, are always expressed in one and the same organ
capable of receiving them and are affections of the same
thing, I mean e.g. health and disease, beauty and ugliness,
strength and weakness, sight and blindness, hearing and

454 « deafness. This is further evident from the following : it

3 is by the same sign that we recognise a person awake
and one asleep. For when a person has sensation we
regard him as awake and we believe that every waking
person has sensation to a certain extent either of the

4 external world or of internal processes. If, then, waking
consists in nothing else than in having sensation, it is
evident that by virtue of that organ wherewith one has
sensation, waking creatures are awake and sleeping

5 creatures are asleep. But since sensation is not the
function exclusively either of the soul or the body (for
where there is potentiality there is also a corresponding
actuality; but what we understand by sensation in its actual
sense, is a psychical process mediated by the body), it is
plain that this phenomenon does not belong exclusively

(MIAI-. I. SLKKI' AND SKNSATION 215

to the soul, and on tlie other hand it is inipossihlc for an
injinimatc body to ox])eri(in(;o sensation.' In earlier 6
treatises ^ we have analysed tlie parts of the soul as we
call them, and explained that the nutritive part is difrerent
from the other powers in animate bodies, althoujjjh no
other ])Ower can exist independently of it. P'rom this it
is evident that such living creatures as are endowed only
with the functions of growth and decay, do not ex-
perience sleeping or waking, as e.g. plants. For they
have no organ of sensation, whether separated from or
conjoined with the organ of nutrition ; — in potentiality
and mode of expression these two organs are separable
from one another. It is likewise true that there is no 7
creature that continuously wakes or continuously sleeps,
but both these conditions are found in the same animals.
If an animal has sensation, it is impossible that it should
not sleep and wake. Both these phenomena refer to the
experience of the primary organ of sensation.^ It is
impossible that either of these conditions should be 8
continuously found in the same creature, e.g. that any
species of animal should sleep or wake constantly, because
whenever we find a natural function, as soon as the
time is exceeded during which the function is capable of
being exercised, the organ necessarily becomes impotent,
just as the eye by exercising vision becomes unable to

1 'Ai(T^a»'0/uai signifies consciousness as well as the physiological
process of sensation.

2 Cf. De an. 415a 23 ff. ; 432a 23 flf. ; 434a 22 ff.

^Namely, the heart. Plants have no central organ {De an. 4116 19),
which is necessary to sensation, and without the latter they cannot be
said to sleep or wake, sleeping and waking being respectively the
activity and quiescence of sensation.

216 Aristotle's psychology desomno

perform this function. The same thing applies to the
9 hand, and to every other functioning organ. Now, if
there is an organ to which the function of sensation
belongs and the time is exceeded during which con-
tinuous sensation is possible, then the organ will become

10 powerless and no longer perform its function. If, there-
fore, waking is defined in terms of this condition, viz. as
the release of sensation from a state of impotency, and

454*^ if of two contraries one must always be present and the
other absent, and if waking is the contrary of sleeping,
(and, consequently, one of the two must in every case be
present), then sleep would be necessary. Consequently, if

11 this is the nature of sleep, and it consists in a loss of
power through excess of waking, and excessive waking is
sometimes pathological and sometimes normal (so that
the incapacity and its recovery would also have the
character of the pathological and normal), it follows that
every waking creature must also sleep. For continuous
activity is impossible. So, too, there is no creature that

12 can sleep continuously. For sleep is a condition of the
sense-orsfan which is like beinf]: fettered and held im-
mobile. Every sleeping thing, therefore, must have a
sense-organ. By sense-organ we mean that which has
the capacity of actual sensation. But to have actual
sensation in its proper and strict sense and to sleep at
the same time is impossible.^ All sleep, then, must be
a condition from which waking is possible. Almost all

13 animals, whether their natural abode is the water, air, or

^••On the whole, the quarrel between Descartes and Locke as to
whether the mind ever sleeps is less near to solution than ever."
James, Principles of Psychology, vol. i. p. 213.

<!IIAI'. I.

SLKKl' AND NUTRITION 217

land, ovidently havi; tlic- j)()wcr ol' alcej). I' or we nee all
varieties of fislu^s and molluscs sleeping and every other
variety that has eyes. Also, the hard-eyed animals and
the insects evidently .sleej). The sleep, however, of all
such animals is brief. And consequently an observer
may not notice whether or not they share in sleep. 14
In the observation of crustaceans it has so far not
been clearly established whether they sleep or not.
If, however, the foregoing reasoning is convincing, then
one will believe that sleep occurs in this class. That
all animals, therefore, share in sleep is proven from
the foregoing. For the definition of animal is given
in terms of the possession of sensation. And we
define sleep as in a certain sense the immobility
and fettering, as it were, of sensation ; waking as the
delivery and release from such condition. No plant can 15
participate in either of these conditions. For without
sensation neither sleeping nor waking occurs. Creatures
that are endowed with sensation feel pleasure and pain.
And when these are felt, desire is also felt. None of
these phenomena, however, is found in plants. A proof
of this is that the nutritive part performs its own
function better during sleep than in a waking state.^ 455 '^
For at this time nourishment and growth are more rapid,
which shows that for these purposes there is no need of
the additional power of sensation.

^ It is a generally accepted fact that nutrition is heightened during
sleep, which is perhaps due to the fact that digestion during sleep is
more regular, being free from mental work or disturbance. Amongst
the lower animals it is usual to sleep after eating. Cf. Spitta, Die
Schlaf- und Traumzustdnde, p. 19; Combe, Physiology of Digestion, 10th
ed. p. 112.

CHAPTEK II.

We must now inquire why it is that sleeping and
waking occur, and to what sense, or senses, if there are

2 several, they are due. Since some animals have all
the senses and others not, e.g. some do not have sight,
whereas touch and taste are universal excepting in cases of
abnormal creatures (and mention has made of these in
the treatise On the Soul ^), and further, since it is
impossible for an animal in sleep to experience any
sensation whatever, it is clear that we shall necessarily
find this condition in all the senses during what we call
sleep. For if an animal were to sleep in one part and not
in another, then it would have sensation in sleep, which

3 is impossible. Now, in every sense there is a power
which is peculiar to it and another power which it has in
common with others, e.g. vision is peculiar to the eye,
audition to the ear, and, similarly, peculiar powers belong
to the other senses. But there is also a kind of
common power that is associated with all the particular
senses, by virtue of which one is conscious that one

I De an. 425a 10 ; 4326 23 ; 4336 31.
218

CHAP. II. TUK CKNTUAL SKNSR 219

scoa 1111(1 lR!iirs. i^'or l)y iiicims ol" si^liL (Jiui doiis not
j)erceivo that oiio sotis, and one diBcriininatcs ancl Ijuh 4
tho power of discrimination between sweet and white,
not by virtue of taste or sight, nor by means of the
two combined, but by means of a certain power wliich
is common to all the sense-organs. For sensation is
unitary and the master-organ of sensation is unitary,
although there is an essentially diflercnt character that
belongs to each category of sensation, e.g. to sound and
colour. This common element^ is allied more nearly to 5
the tactual than to any other sense. For the tactual can
exist apart from all the other sense-organs, but the others
cannot exist apart from it. This, however, was discussed
in the studies On the Soul} Sleeping and waking, then,
are evidently an affection of this common sense, and are
consequently found in all animals. For touch is the 6
only universal sense. Now, if sleep consisted in the fact
that all the senses undergo something, then it is remark-
able that in cases where it is not necessary, or in a certain
sense not possible, for them to be simultaneously active,
yet these same senses should become simultaneously in-
active and immobile. On the contrary, it is more
plausible to suppose that they are not at rest simul-
taneously. But the explanation that we have given of 7
these phenomena is a rational one. For when the master-
organ that rules over all the others and to which all the

^ The function of consciousness is ascribed to the central or common
sense, whose organ, in common with that of touch, is the heart [De sensu
4386 .30, 469a 12). The following sentence, in the text, does not mean
that the common sense can exist apart from the special senses, but
that both touch and the common sense are necessary to the others.

2 De an. 4136 32 flf. ; 4346 23. Vid. also Dejuvent. 4676 28 ff.

220 Aristotle's psychology de somno

455^ others are directed, is affected, all the subordinate organs
are necessarily affected with it ; on the other hand, when
one of the latter is disabled it is not necessary that the

8 master-organ should be disabled also. But it is evident
from many considerations that sleep does not consist in
the inactivity and non-use of these special senses, nor in
their incapacity to experience sensation. For this is just
the sort of thing that happens in swooning : swooning is
the exhaustion of the senses. And there are also certain
other kinds of mental disturbances that resemble this.
Also, by compressing the jugular vein, one loses

9 sensation. But whenever there is a loss of the use of
sensation, it does not find its explanation in any chance
sense nor is it attributable to any haphazard cause, but
the explanation is found, as we just now said, in the
primary organ of all sensation. For when this is
disabled, all the other sense-organs are also necessarily
unable to have sensations. When, however, one of
these latter loses the power to act, the common sense
is not necessarily disabled.

We must inquire to what cause sleep is due, and what

10 sort of an affection it is. Now there are several kinds

of cause ^ (for we speak of cause in the sense of the

^ Aristotle views the world under the aspect of processes dominated
by two causal principles — form and matter. He conceives of the latter
as potentiality, which in a world of movement passes over into a
condition of actuality. Actuality is synonymous with form. In
organic processes these two things are separable only in abstraction.
Form represents the completed condition towards which matter strives.
Form is therefore the end, or otherwise expressed, the final cause.
Further, as the completed notion of a thing, or that which a thing
really and finally is, it is the essential or notional cause. The defi-
nition of a thing is its notional cause. Cause (atVia) is here, of course,
employed in a sense foreign to English usage. There is no idea of

(JiiAi-. II. FORM ANh MATTKR 221

end or purposo; u;j;iiin hh the jdincij)!*' of motion, as
the material condition, and as tlu; notion m loini). I'irst
of all, then, when we say that natun; acts with a
purpose, we mean that tlii.s pur])oso is some f^ood, that
rest is provided for every creature whose nature it is
to move, and that, bcin^^ incaj)al)le of constant and con-
tinuous pleasurable movement, this rest is a necessary n
and useful thing (and the metaphorical term 'rest' is with
perfect accuracy applied to sleep as repose). Conse-
quently, sleep exists for the preservation of animals, and
the waking state is its final cause and purpose. For 12
sensation and thought are the final purpose of all
animals that possess either of these powers. These are
their highest activities, and the highest is the end.
Sleep, therefore, is a necessity for every animal. I
mean here a hypothetical necessity, viz. that if an 13
animal is to preserve its nature, it must necessarily be
provided with certain things, and where these things
are found, other things are involved. We mvst next
ask to what sort of bodily process and activity waking

agency in it, as there is in all English meanings of cause. It signifies,
rather, ' principle. ' Further, form represents the inner Trieb or force
in matter whereby it is in constant transition towards the realisation
of its end. In this sense form is the efficient or moving cause. We
have then form used in the various senses of (1) final principle, (2)
notional principle {i.e. the notion or significance of a thing), and (3) the
efficient principle. The first and third are conceived of as forces or
causal agents, while the second is cause in the sense of being the source
from which these forces issue. The two ultimate principles, then,
which Aristotle employs for the explanation of all reality and all de-
velopments are :

1. Form (the essential thing). 2. Matter (material condition).

(a) End or final cause,

(5) Motion or efficient cause.

222 Aristotle's psychology desomno

and sleeping are due. We must assume that the causes
of sleeping and waking are the same or analogous
in bloodless and sanguineous animals, and in the lower
sanguineous animals and men. So that what we observe
in the case of man, we shall have to apply to them all.

14 It has been already determined in other treatises that
456 a the origin of sensation is found in the same organ from

which motion originates. This organ is found in the
middle division^ of the three topical sections of the
body, and lies between the head and lower body. In
sanguineous animals it is the pericardiac section, for
all sanguineous animals have a heart, and this is the

15 primary source of motion, and of the higher sensation.^
Evidently the origin of movement and of breathing,
and in general of refrigeration, is found in this section,
and it is also evident that nature created the organs of
respiration and of refrigeration, which latter is effected by
means of moisture, for the purpose of maintaining the
warmth in this part.^ But this subject will receive

16 separate treatment later.* On the other hand, in the
bloodless animals, the insects, and such animals as
are incapable of breathing air, there is found in an
organ corresponding to the lungs congenital air which
rises and falls. This is evidently true in the case of
insects with undivided wings, such as wasps and

1 Thorax.

'The "higher sensation" appears to mean sense-perception or the
apprehension of the 'common sensibles.' Cf. Introduction (chap, iv.)
on the nature and function of the 'common sense.'

^ That is, for the purpose of maintaining normal animal heat, and
for guarding against its excess.

* Vid. the tractate (hi Respiration.

<iiAf. II. MOVKMKNTS IN SLKKI' 223

bees, also in Hies and siniilar inHuctM. I'ut since it 17
is impossible to ori^Minil-o motion williouL power, tbe
retention of the, lucalli [generates power — breatb derived
from witbout in tbe case of respiring creatures, and con-
genital breatb in tbe ease of non-respirin*^ animals (tbis
is tbe reason vvby, as we see, win<^ed insects l)uzz wlien
in motion, tbe sound beinj^ caused by tbe friction of tbe
air 8trikin«jj on tbe diapbragm of tbese boloptera). Every 18
creature experiences movement wbonever a sensation,
wbetber its own or caused from witbout, is awakened in
the primary organ of sensation.^ Now, if sleeping and
waking are affections of tbis organ, it is clear in wbat
region and in wbat ultimate organ, sleeping and waking
have tbeir origin. Tbere are persons who are subject 19
to movements in sleep, and do many acts that belong to
the waking state, and nevertheless without any image
or sensation. For the dream is in a certain way a
sense-perception. About this we must speak later.
Why it is that we remember our dreams on waking,
while we do not remember acts done in a waking state,
has been explained in the FroUems.^

^ Motion {Kivriffis) is employed by Aristotle in several senses. He not
only constantly speaks of intellectual processes as motions, but refers to
movement in space as motion. The generic term is Kbrjais, which has
the following varieties {Metaph. 10696 9 ; De an. 406a 12, 4326 9) : (1)
Quantitative motion, or motion in reference to magnitude (/card fi^yedos),
which signifies increase and decrease [av^-qais /cat <pdiais) ; (2) Qualita-
tive motion (/card to ttolou), or transformation {dWolwais) ; (3) Spatial
motion or locomotion (/card to ttov, called (popd) ; (4) Substantial change
(/xera^oXr) kut^ ovffiav), or birth and destruction (761^60^5 /cat (pdopd).
Aristotle declares, however, that the last named {Phys. 225a 26,
2256 10) is not a proper form of motion, on the ground that the non-
existent cannot be said to experience motion.

"^ The explanation here referred to is not found in the extant Problems.

CHAPTEK III.

Following upon what has been said, we have to consider
to what occurrences the phenomenon of sleeping and

2 waking is due and what is its origin. Now, it is plain
that as soon as an animal has sensation, it must at once
take nourishment and grow ; food in its final state is,
in all sanguineous animals, blood, and in bloodless animals

456 b something analogous to blood. The blood is contained in
the veins, the origin of which is found in the heart (a

3 fact which is demonstrated by dissection). When food
has been introduced from without into those parts
intended for its reception, an evaporation takes place in
its transmission into the veins, and here it is transformed

4 into blood and is carried to its main organ. This subject
was discussed in the treatise On Food} But we must
resume it now for the sake of observing the origins of
animal movement and of seeing to what atfection of the

5 organ of sensation waking and sleeping are due. For
sleep is not any random exhaustion of the power of

1 The work On Food {-n-epl Tpo(p7]s) appears to be referred to in De an.
4166 31, but whether or not it was actually written is uncertain. It is
not in the present Corpus of Aristotle's writings.

224

HHAI-. ill. ANIMAL UKAT AND SLKKI' 226

sensation, as s.iid abovo. SenHolosaness, choking,', and
swooning product; ji .similar oxhau.stion. And in some
cases of svvooniiii^ Ihc^re has been lound even a stron*^
power of imaj^ination. Now this creates a problem. 0
Kor if it, is possible for a swoonin^j; person to fill
asleep, then this ima<,nnation might be re<:jarded as a
dream. Also, people often talk when they aic^ in a
deep swoon and are to all appearances dead. To all
these cases of swooning, however, we must suppose that
the same explanation applies. Hut, as we have said, sleep 7
cannot be any and every incapacity to feel sensation; on
the contrary this particular condition springs from the
evaporation of food. For the evaporation must be thrown
off to a certain extent, and then it must return and
change again, like the ebb and Hood of a shifting strait. 8
All animal heat tends to rise ; when, however, it reaches
the upper parts, it turns about and courses down again
in mass. Consequently, sleep is most easily produced
after taking food. For a large quantity of moist crass 9
matter is then carried to the upper parts. This by
remaining there produces heaviness and causes one to
fall asleep. But when it descends and in turning
throws off its heat, then sleep ensues and the animal
slumbers. A proof of this is furnished by the action of
narcotics ; for they all, whether liquid or solid, produce
heaviness, e.g. the poppy, mandrake, wine, and bearded
darnel. And those who droop their heads and nod into 10
slumber appear to be in this heavy condition ; they
cannot lift their heads or eyelids. Sleep of this sort
follows mostly on the taking of food. For there is then a
strong evaporation from food. It further arises from

226 Aristotle's psychology desomno

certain fatiguing efforts. For fatigue tends to waste, and
457 a waste-matter is like indigested food, when it is not cold.

11 Certain diseases, such as are due to an excessive amount
of moisture or heat, produce this effect of sleep, as is the
case, e.g. in fever and lethargy. Further, early infancy
produces it ; for children sleep a great deal because all

12 their food rises to the upper parts. A proof of this is
seen in the excessive growth of the upper parts in propor-
tion to the lower ones in early childhood, due to the fact
that growth tends in that direction. It is to this cause
also that epileptic conditions are due. For sleep is similar
to epilepsy, in fact is epilepsy in a certain sense. And

13 so the beginning of this condition in many cases happens
during sleep, and while asleep persons have an attack of
it, but not while awake. For when a great mass of
fumes is carried to the upper parts, in descending they
press on the veins and produce constriction of the passage

14 through which respiration takes place. Consequently,
wine is not good for children or for wet-nurses (for it
makes no difference, perhaps, whether the wine is
taken by the children or by the nurses), but they
should drink it thinned with water and in small quanti-
ties. For wine contains spirituous fumes, especially

15 wine of dark colour. In children the upper parts
become so full of food, that during five months of life
they cannot turn their necks. For a great quantity of
moisture rises to the upper parts, just as it does in the
case of persons who are very drunk. This phenomenon
suggests a rational explanation of the fact that the

16 embryo remains at first quiet in the womb. Also, in
general, persons with deep lying veins, of dwarf-like

cnAi'. III. FOOD AND SLKKI' 227

structuro, mid willi hwyv IicjuIh, are ^ivon to sleep. For
the veins of (he one clasw jirc^ hiiihU mid ho the rnoiHlun;
in its downward courHc; cannot nMulily flow tlirou^di tliein,
while in thi» caHc^ of persons of dwarf-like structure
and lar«j[e heads, there is a great pressure and evaporation
towards the upper parts. Large- veined persons are not 17
given to sleo[) because of tlie facility for the passage of
blood ^ in the veins, unless there be some adverse con-
ditions })resent. Neither are the atrabilious especially
inclined to sleep. For their internal parts are cool and
so no considerable evaporation takes place in them.
Consequently owing to their dryness they are fond of
eating. For the condition of their bodies is such that
they seem to have eaten nothing. For the black bile, 18
being in its nature cool, cools the nutritive region and
the other parts, where this excretion of bile is potentially
present. From the foregoing, one sees that sleep is an 457 ^
internal concentration of heat and a natural reaction from
the cause named. For this reason a person in sleep 19
moves a great deal. From the moment that the heat
ceases to rise, however, the person becomes cool and owing
to the cooling the eyelids fall shut. And so the upper
and outer parts of the body are cool, while the inner and
lower ones, e.g. the feet and the entrails, are warm. Yet 20
one might be in doubt as to the statement that the
deepest sleep occurs after eating, that wine and other

^ The circulation of tlie blood was, of course, unknown to Aristotle.
He knew only of its direct passage from the heart to the extremities
and of its movement to the brain and return. (4566 23 ; De insom. 4616
7 flf). The brain, being the coldest organ of the body, performed the
function, as Aristotle supposed, of reducing and regulating the tempera-
ture of the blood.

228 Aristotle's psychology desomno

similar heating drinks are narcotic. To regard sleep as a
cooling process is not reasonable ; it is rather caused by

21 heat. Or is one to suppose that analogously to the
stomach which is warm when it is empty but as soon as
it is filled becomes cool through its processes, so the
channels and divisions of the head are cooled by the rise
of evaporated matter ? Or are we to suppose that
analogously to persons pouring warm water over them-
selves and then suddenly shivering, so after the heat has
risen, the collected cold produces a chill and in this way

22 counteracts the natural heat and drives it back ? Again,
when a large quantity of food is taken, which drives the
warmth upward, the stomach is cooled, until digestion
takes place, just as fire is cooled when fresh wood is laid
upon it. For sleep occurs, as we said, when crass
evaporation under the influence of heat, rises through the

23 veins to the head. When this can continue no longer,
because an excessive mass has been carried to the upper
parts, then reaction takes place and the evaporated
matter flows back to the lower parts. Consequently
when the rising heat is withdrawn, men sink down
(man is the only animal that stands erect), and when the
heat returns, it causes lapse of consciousness, and later

24 awakens imagination. The explanation we have just
given for the phenomenon of refrigeration is a possible
one. The region about the brain, however, is the chief
factor here, as we have said. The brain is the coldest
part of the body, and in animals that have no brain

25 the part analogous to it is the coldest part. Just
as water is evaporated by the sun's heat and, when
it rises into the upper air, is cooled by the air's

€HAP. 111. TUK liLOOI) AND SLKKI* 229

tempcraturt^ and coiiilcii.scd fulls to tho (ijirtli once, iiiurcj
in tho form of wator, so in the rise of heat to the 458 a
brain, the excessive evaporation is converted into viscid
matter (for this reason catarrlial affections appear to
come from the brain), whereas the evaporation that
assists nourishment and is normal, returns to the lower
parts condensed, and decreases the lieat. The thinness 26
and slender structure of the veins about the brain con-
tribute to refrigeration, and to the diiliculty of their
taking up the evaporation. This is the cause of re-
frigeration, even in cases where the evaporation creates
an excessive degree of heat. Waking takes place when 27
digestion has been completed, and the great amount of
heat which is crowded into a small region out of the
surrounding parts, has gained control ([over the cold]),
and when, further, the crass blood has been separated
from the purified blood. The thinnest and purest blood
is in the head, the thickest and most turbid in the
lower parts. The primary source of all blood is, as 28
we have said in this treatise and elsewhere,^ the heart.
Between the two chambers of the heart there is a
middle chamber connected with both. ^ The two

^ De part. an. 6486 4 ; de juvent. 4686 32 ; de respir. 4746 7.

■' According to Aristotle there are three cavities or chambers in the
heart, which he calls right, left, and middle. The right cavity is the
largest, the left one the smallest, and the middle one is middle-sized.
The right cavity in Aristotle's conception is identical with the right
ventricle, which he saw in a suflFocated animal and in a disturbed state,
so that it appeared larger than the middle cavity (the left ventricle).
This in turn appears larger than the collapsed left auricle, which is
Aristotle's left cavity. The fourth cavity or right auricle was merged
by Aristotle in the great vein, because, as Huxley says {Nature, vol.
xxi. p. 2), the vena cava inferior, the right auricle, and the vena cava
superior and innominate vein, when distended with blood, appear *'to

230 Aristotle's psychology desomno

chambers severally receive blood from the two arteries,
from the great artery and the aorta, and the sepa-

29 ration takes place in the middle chamber. The detailed
treatment of this subject, belongs, however, more
properly to other treatises. On account of the un-
separated character of the blood after taking food sleep
occurs and continues until the purest element is sepa-
rated off and carried to the upper parts, and the more
turbid element to the lower parts. When this is accom-
plished, sleepers are released from the heaviness caused

30 by food and awake. The cause of sleep has, therefore,
been explained as the reaction of crass vapour, which
rises under the influence of its inherent heat on the
primary organ -^ of sensation. Sleep has also been
explained as the inhibition of the primary sense-organ,
and its incapacity for function, and as a necessary pheno-
menon (for no animal can exist apart from the conditions
which develop its nature), and sleep ^ exists for the sake
of preservation, for rest preserves.

form one continuous column, to which the heart is attached as a sort
of appendage." Consequently, instead of a right and left auricle and a
right and left ventricle, Aristotle distinguished only three cavities, a
right, a left, and a middle. Cf. De histor. anim. 496a 4 ff.

iThe heart.

'^For the history of the various ancient theories of sleep see Spitta,
Die Schlaf- und Traumzustdnde der meiischlichen Seele, Tubingen, 1882,
pp. 2 ff., and Radestock, Schlaf und Traum^ Leipzig, 1879, pp. 240 ff.

ON DREAMS.

CHAPTEK I.

We must next investigate dreams and inquire first of
all in what part of the soul this phenomenon occurs, 458 3
and whether it is an affection of the thinking power
or of the sensible power. For it is solely by these two
powers within us that we know at all.^ If the use of 2

^ Dreams are due to revived movements originally set up by external
stimuli as well as to immediate sense-impressions. The former are
centrally excited, to use a modern distinction, while the latter are peri-
pherally excited (cf. 4606 25 ff., 462a 8 ff., 463a 7 ff., 779a 14). In
our waking state these movements are for the most part obliterated
or obscured by stronger currents of thinking or feeling. In sleep, when
the blood is less disturbed, these dream-movements come to clear con-
sciousness. So it is that a bodily discomfort that is not felt in waking
stirs a dream in sleep. It also happens that a dream may lead to action
by day. Dreams, which are images or after-motions of sensations, are
regular or distorted in proportion to the amount of physical disturbance
at hand and the number of cross-sensations (461a 16). Aristotle defines
a dream as "a movement in the organs of sense produced by imagina-
tion" (462a 8, cf. 462a 28). Dreams rise to the surface of conscious-
ness when they are released from the stronger movements that restrain
them, just as artificial frogs rise to the surface when the salt is melted
off (4616 16).

2Cf. De an. 429a 31, 4316 20 ff.

231

232 Aristotle's psychology deinsom.

sight is vision, and of hearing audition, and of sense in
general sensation, and, on the other hand, if there are
common sensibles^ such as form, magnitude, number, etc.,
and particular sensibles, such as colour, sound, flavour,
and, further, if it is impossible for any animal to see with
its eyes closed and asleep, and if this applies equally to
the other senses, then it is evident that we have no

3 sensation in sleep, and so it is not by means of sensa-
tion that we experience dreaming. Neither are dreams
mediated by opinion. For we not only say that an
approaching object is a man or a horse, but also that
it is white or beautiful, as to which qualities opinion^
apart from sensation makes no deliverances, whether true

4 or false. However, this is just what the soul does in
sleep. For, as in waking, so in sleep, we believe we see
that the approaching object is a man, and that it is white.
Again, we think of other things along with the dream,
just as is the case with perception in our waking state.
For we also often think about what we perceive. So in
sleep along with our imaginings we sometimes have

5 different thoughts. This would become apparent to
anyone who would give attention on rising and try to
remember. There have been persons who have in this
way observed their dreams, as e.g. those who try to arrange
their deliverances in accordance with the precepts of the
mnemonic art.^ For it often happens in their case that
along with the dream they put something else, an image

^Dean. 418a 15.

2Z>e an. 421h 20 ff., Post. Anal. 88& 33 ff. Opinion refers to the
contingent or to that which may or may not be true (fVSex^/xeva de Kai
(LWdjs ^xeij/).

3Cf. Top. 1636 ff., De an. 421b 19.

ciiAi'. I. DKKAMS ANI> ILI.IJSION 233

belbro their fyus, in tho placo in (luostion. And ho it is 6
clear that not awry uiuv^fn Hcon in Hleop is a dri-ani, and
what wo think conceptually we regard as true or false
throu!j;h the or^an of oj)inion. So much is clear on this
subject that the same agency which in disease j^roduces
illusion while we are awake, also produces the condi-
tion of illusion in sleep. Even when we are in sound
health and know the truth, still the sun appears to us
to be only a foot in diameter. But whether the soul's 7
powers of imagination and sensation are the same or
dilferent, in any case dreams do not take place indepen-
dently of seeing and some sort of sensation. For illusions
of sight and hearing occur when a person really sees and
hears something, although not the thing that he thinks
he sees or hears. In sleep, however, there is according
to the foregoing hypothesis no seeing, no hearing, no 459 a
sensation at all. The hypothesis that there is no vision 8
is, therefore, untrue, and that sensation experiences no
excitation is untrue; on the other hand, it is possible
for sight and the other senses to undergo some change
and things impinge on each of them to a certain extent,
as in the sensation belonging to the waking state, though
with a certain difi'erence. Sometimes opinion declares
that the seen object is false, as in the waking state; some-
times it is held in check and conforms to the imagination.
Evidently the affection which we call dreaming does not 9
belong to opinion or to the thinking. part of the soul.
Neither does it belong to the sense-part unqualifiedly.
For it would then be possible to see and hear unqualifiedly.
But we must consider in what sense and in what way it
attaches to the part. Let us take this evident fact for a 10

234 Aristotle's psychology deinsom.

starting-point, that if sleep is a condition of the sensitive
part, so is dreaming. For sleeping and dreaming are not
ascribable to different animal organs, but to the same
II organ. Inasmuch as we discussed imagination in the
treatise On the Soul^ and inasmuch as we find that the
power of imagination is one with that of sensation, only
that the mode of expression in the two cases is different,
imagination being a process stimulated by an actual
sensation, and since dreaming appears to be a form of
imagination (for we call an imagination which we
experience in sleep a dream, whether it is unconditioned
or conditioned), it is evident that dreaming is a condition
of the sensitive part,^ but of the sensitive part in its
power to imagine.

1 De an. 421b 14, 429a 9. ^ yi^^ Note 1, p. 2.3L

CHAPTER TI.

We might best observe the nature of dreams, and the
way in which they are caused, from the standpoint of
what occurs in sleep. For sensible objects stimulate
sensation in the several sense-organs, and the mental
condition produced thereby is not only present during
the active process of sensation, but persists after the
sensation has gone. The phenomenon here seems
to be similar to that observed in the case of thrown
objects. For in the case of a thrown object, the 2
movement persists although the mover is no longer
in contact with the thing. For the moving body
communicates motion to a certain part of the atmos-
phere, and this in turn sets another part in motion.
And in this way motion is caused both in the air and
in water until the body comes to rest. One must 459*
suppose that something like this takes place also in
qualitative^ change. A body that is warmed imparts
by means of its heat warmth to the adjacent body, and

' For Aristotle's conception of the various forms of motion, see
Note 1, p. 223.

235

' 236 Aristotle's psychology deinsom.

/ this in turn distributes it further on until it reaches its

3 terminal point. This, therefore, is what must take place
in the organ wherewith we experience sensation, since
actual sensation is a kind of qualitative change. Conse-
quently, this condition is found in the sense-organs not
only during the process of sensation, but also after the
process has ceased, and in their inner depths as well as

4 on the surface. This becomes evident when we have a
sensation that continues over some time. For when we
turn our senses to something else, the original sensation
persists, as e.g. when we turn from the sun to a dark
object. The result is that one sees nothing owing to the
fact that the sense-process, stimulated by the light, still
lurks in the eyes. And if one looks a long time at a
single colour, whether it be white or green, things appear
to be similarly coloured wherever we turn our eyes.^

5 Again, if we look at the sun or some bright object, and
then shut our eyes, there appears to sharp observation, in
the direct line which vision employs, first of all a colour
like the actual one, which then changes to scarlet, then to

6 purple, until it passes into blackness and vanishes. Also,
the senses are affected in this way when they turn
quickly from objects in motion, e.g. from looking at a

^Aristotle refers to the familiar phenomenon of 'after-images.'
The fact that the attention was tixed (in Aristotle's illustration) a
considerable time, and that he mentions the 'flight of colours,' shows
that the reference is to ' positive after-images ' and not to * primary
memory images,' a distinction unknown, of course, to Aristotle. Cf.
Sully, The Human Mind, vol. i. p. 278; James, Principles of Psychology,
vol. i. p. 645; Ebbiughaus, Grnndzilge der Psychologie, p. 244;
Helmholtz, Handhuch der physiologischen Optik (ed. 1867), pp. 366 ff. ;
Wundt, Human and Animal Psychology, pp. 108 ff. ; Titchener,
Experimental Psychology, vol. i. part ii. pp. 48 f.

ciiAi'. ri. TUK FA'K AND THK MIKKOK 'SM

river, and especially tVoiii lookiii}^ at swiftly flowing
streams. For objects at rest then seem to be in ni(jtion.
And men are made deaf by loud noises, and their sense
of smell is destroyed by strong' odours, and so on. This
evidently occurs as we describe it. 7

That sense-organs readily detect even minute distinc-
tions is proven by the use of a mirror, concerning which
fact one might stop at this point to investigate and make
inquiries. From these inquiries it will at the same time
become plain that just as sight is subject to an impres-
sion, so it exercises an activity. When women look into 8
a very clear mirror^ after their menstrual flow, the mirror's
surface becomes covered with a bloody cloud, and if the
mirror is new the stain is hard to remove, but if it is old 9
the removal is easier. The reason is that the eye, as we 460 a
said, not only receives an impression from the air, but it
also produces an impression and a movement, just as
bright things do. For the eye is classed amongst objects
that are bright and possess colour. Eyes are constituted
in the same way, it is reasonable to suppose, as any other

^ Ancient mirrors were made of polished metal. The phenomenon
here described is one of many of the old-wives' stories which Aristotle
took up in his treatises and to which he appears to have given credence.
Aristotle, we must remember, had no considerable body of critically
sifted and scientifically accredited data to work with. He was depen-
dent chiefly on his own observations and the reports brought to him by
unskilled persons, in an age before people had concerned themselves
about the laws of evidence. It is just this historical environment
that shows us how great was the ordinarily sober judgment of Aristotle
and how unparalleled his acumen in seeing the scientific significance of
facts. It is, however, curious to note that Roger Bacon accepts the
story as true : ' ' quoniam si ipsa [mulier menstruata] aspiciat speculum
novum, apparet nubes sanguinea in speculo ex violentia menstrui
inficientis {Opus Majus, ed. Bridges, vol. i. p. 142). Cf. Lewes,
Aristotle, p. 172.

238 Aristotle's psychology deinsom.

bodily organ. And so they naturally contain veins.

10 When, therefore, the menstrual flow takes place, owing to
disturbance and flow of blood, there is a difference in the
eyes, imperceptible to us, but nevertheless real (for the
seed and the monthly flow have the same nature), and
the air is set in motion by the eyes, and the air being
continuous to the mirror, it imparts to the latter a cer-
tain quality and an impression similar to the one it has
itself received. The air affects the surface of the mirror.

11 But as the cleanest clothing is the most readily stained,
so it is here. For a clean thing shows exactly whatever
taint it receives, even the slightest effects, more than other
things do. Bronze especially, owing to its smoothness, is
affected by every contact (we must regard the contact of
air as a kind of friction, as cleaning or washing), and
owing to the purity of the bronze this contact, however

12 slight, becomes visible. The reason why stains are not
readily removable from new mirrors is to be found in the
fact that they are clean and smooth. For stains pene-
trate deep into such mirrors and in every direction ; for
owing to the mirror's pure surface the spots go deep and
owing to its smooth polish they spread in all directions.
In old mirrors the stain does not fasten, for it does not

13 penetrate so deep but stays rather on the surface. From
these facts it is evident that movement is excited by
slight distinctions, that sensation is swift, and further,
that the sense-organ for colour not only receives
impressions but also reacts on external objects. Facts
regarding wine and the preparation of ointments also

14 furnish proof for these statements. For the prepared
oil and wine readily take up the smells of adjacent

oiiAF. II. ILLUSION IN DRKAMS 239

objects aiul they become tainted not merely with the
smell of thinjjjs thrown into them or mixed with them,
but also of things that iire placed or grow in tlieir near
neighbourhood.

In reference to our original inquiry let us hiy down 460 />»
one fundamental truth, which is evidenced by what has 15
been said, viz. that after the removal of the external
sensible object, the experienced sensations persist. To
this we must add that when under the influence of strong
feeling we are easily deceived regarding our sensations,
different persons in different ways, as e.g. the coward
under the influence of fear and the lover under that of
love have such illusions ^ that the former owing to a
trifling resemblance thinks he sees an enemy and the
latter his beloved. And the more impressionable the
person is, the less is the resemblance required. Similarly 16
everybody is easily deceived when in anger or influenced by
any strong desire, and the more subject one is to these
feelings the more one is deceived. This is the reason why
men sick of a fever ^ sometimes think they see animals on
the walls owing to some slight resemblance in the figures
drawn there. And this tendency to illusion at times 17
keeps pace with the intensity of the emotional experience,
so that in cases where the patient is not very sick, he is
still conscious of the deception, but where his condition is
more aggravated, he even rushes upon these animals.
The explanation of this phenomenon is that the intellect

^Aristotle here notes certain of the main causes of ordinary illusions
and hallucinations, although the hallucination of fever-delirium is here
described rather as illusion. The sense-stimulus is there in the picture
on the wall, but the inference is false. Cf. James, Principles of
Psychology^ vol. ii. p. 86.

240 Aristotle's psychology deinsom.

i8 and the faculty in which our images ^ arise do not pass
judgment with the same power. A proof of this is that
the sun appears to us only a foot in diameter and there
is many another fact which contradicts our imagination.
Also by crossing the fingers ^ a single object under them
appears to be two and yet we do not say there are two ;

19 for sight is more decisive than touch. If, however,
touch were our only sense, our judgment would declare
that the single object is two. The source of illusion is
found in the fact that things, whatever they may be, are
perceived not merely while the stimulation of the sense-
object continues, but also during the further activity of
the sense itself, if this movement is the prolongation of
that awakened by the sensible object. I mean, e.g. the
shore appears to sailors to move, although it is by some-
thing other than the shore that the eye is set in motion.

^ Read u> rd (pavTacrfjiaTa yiyveraL instead of rd (pavrdafxara yiyueadai
(4606 17). The imagination, in Aristotle's psychology, does not pass
judgment, although the 'common sense,' in which phantasms reside,
has this power.

2 This is the oldest example of illusion, so far as I know, in the history
of psychology (cf. James, Principles of Psychology, vol. ii. p. 86).
The illustration has become classical. In the normal position of our
fingers (from which part of our tactual world has been built up), it is
impossible to place the radial side of the index finger and the ulnar side
of the middle finger on a marble or similar small object at the same
time. Consequently when we cross our fingers and perform this feat of
touching the radial side of the one and the ulnar side of the other with
a marble, we seem to touch two objects, because these two points
on our skin are never touched by a single object at the same moment.
Aristotle further refers to this instance of illusion in Prohl. 9586 14,
and Metaph. 1011a 33. For a detailed discussion of this and similar
forms of illusion, vid. Henri, Uber die Raumwahmehmungtn des
Tastsinnes, pp. 67 ff.

CHAPTEJi III.

From these considerations it is clear that sense-processes,
whether aiising frotn external objects or bodily activities,
take place not merely during the waking state, but
occur also in sleep, and that at this time they appear
even more numerous. For during the day they are 2
kept in the background by the combined activity of
the senses and the intellect, and so are obscured, just 461 a
as a small tire is obscured when placed alongside a larger
one, or as trivial pleasures or pains are obscured alongside
of great ones, but when the latter have vanished then
the smaller ones rise to view. At night, owing to the
inactivity of the special senses and their incapacity to
function, caused by the return flow of heat from the
outer into the inward parts,^ these sense-movements
are carried to the primary seat of sensation and
become clear, when the disturbance has subsided. And
we must suppose, as tiny whirlpools occur in rivers, so 3
each movement goes on continuously, frequently in the
same direction, and attain resolved into other forms
through counter-influences. Consequently after eating, 4

1 Cf. De somno, 4576 20 ff.
Q 241

242 Aristotle's psychology deinsom.

and in the case of very young persons, as e.g. in children,
dreams do not occur. For there is a strong movement

5 excited by the heat in food. The case here is similar to
what occurs in water when it is violently agitated, viz.
sometimes no image is reflected and sometimes only an
entirely distorted one,^ so that the thing appears different
from the reality. On the other hand when the water is
still we see clear and distinct images. So, too, in sleep
the images and residual movements resulting from
sensations are sometimes entirely obliterated by a move-
ment greater than the given one, and sometimes visions
appear confused and monstrous and the dreams are not
marked by normal health, but are such as one finds in
the atrabilious, in men sick of a fever, and in men that
are drunken. For all these conditions are like flatulency,

6 and excite great movement and disturbance. But when
in sanguineous creatures the blood has come to rest and
is separated off,^ the movement of sensation that proceeds
from each sense-organ and persists, awakens normal
dreams and causes an image to appear and the person to

1 Of. note 1, p. 23L Sensations cause after-movements like the ripples
and circles in water agitated by a pebble. These movements repeat
themselves in fainter form, clearly in still water, and with distorted,
broken shapes where the water is disturbed by cross-movements.
The circles or images are then confused or monstrous. If the movement
is too violent, as after eating and in children, then, as in violently
agitated water, no image or dream is produced.

2 That is, purified from crass elements. Although Aristotle makes a
distinction between pure and crass blood, it is not certain that these
are to be connected with the aorta and vena cava, or that they in any
way correspond to arterial and venous blood. This separation takes
place in the heart, which is at once the physiological and the psychical
centre of animal life, — the "acropolis of the body" {De part. anim.
670a 26).

oiiAi'. 111. MOVKMKNT IN DIIKAMS '2\:\

believe Llial lu; scu's soiiiclliin^' owiii".^ to the iiilluenceH
diselmrt^ed IVoin sight, and to hvar owin*,' to the iiilluenceH
discharged tioin hearing, and similarly with the other 7
senses. For by the transndssion of this movement from
these special organs to the primary seat ' of sensation,
one believes, in the waking state, that one sees and hears 461 *
and perceives ; and because it sometimes happens that
sight seems to be stimulated without its being really so
stimulated, we say that we see, and because touch reports
two movements, we believe a single object to be two. In 8
a word the primary sense affirms the deliverances of the
special sense, when no other more decisive sense con-
tradicts this. There is without doubt an appearance,
but what appears is not in every case believed, unless
the power of judgment is inhibited or is not exercised
in its normal way. But as we said that some 9
persons are subject to illusion under one condition and
others under another, so when asleep, one is deceived
by the processes of sleep, by the excitations of the
sense-organs, and by other affections of sensation,
to such a degree that something which bears only a 10
slight resemblance to a given thing is thought to be
that thing. For when one is asleep and the mass
of blood recedes to the central organ, the movements
in the blood, whether latent or actual, concentrate
there.^ And the conditions here are such that if the
blood is stirred, a particular movement rises to the
surface and if this subsides, then another follows. They
are related to each other like artificial frogs which rise to
the surface of the water as soon as the salt on them is n

1 To the heart. ^ ^g so77ino, ioQb 23. Cf. note, p. 227.

244 Aristotle's psychology de insom.

melted off. And so these movements are latent in the
blood, and as soon as the hindrance is removed they
come to active expression. When set free in the small
amount of blood remaining in the sense-organs, they stir
themselves, exhibiting a likeness to things such as we see
in clouds, which resemble men and centaurs in quickly

12 shifting forms. Each of these images is, as we have said,
the residue of actual sensation. After the true sensation
has gone, the image continues, and it is correct to say that
it is something like Coriscus although not Coriscus. And
at the moment of sensation the master-organ and judging
faculty do not say that this is Coriscus, but only that
owing to this sensation the real Coriscus is yonder

13 person. On experiencing this sensation the master-sense
makes the above deliverance, provided it is not entirely
inhibited by the blood, just as without sensation this
movement is set up by the processes latent in the sense-
organs. This latter, which resembles a thing, one then
regards as the real thing. And the power of sleep is so

14 great that it causes us to be unconscious of this difference.
If one presses one's fingers under the eyes and does not

462 a notice it, a single thing not only appears double but is
believed to be so ; if the pressure is noticed the thing
appears to be double but is not believed to be so, and
this is what happens in sleep. If a person perceives
that he is asleep and is aware of the sleeping condition
in which the sensation occurs, then the appearance will
be present indeed, but there is something in the person
which says this is only a phantasm of Coriscus and is
not Coriscus himself (for there is often something in the
soul of the sleeper which says that the appearance is

(-)iAi-. III. IMAOINATION IN DliKAMS 245

only a dream). If, however, he is iiuL cuii.sciouH u{' the
sleeping state, then nothing eontradicts the imagination.

That the above statement is correct, and that we have 15
movements of imagination in the sense-organs, becomes
clear, it' in falling asleep and on waking, we attentively
try to remember what happens.^ For sometimes one
will detect, on waking, that the images which appear in
sleep are movements in the sense-organs. In the case
of certain young persons whose sight is thoroughly good,
there appear before them, when it is dark, a multitude of
moving images, so that they conceal themselves in fright.
From all these facts one must conclude that a dream is 16
a kind of sleeping phantasm. For the imaginings in
children just referred to are not dreams, nor is anything
else which is seen when we have the free use of our
senses. "Neither is every imagination that occurs in
sleep, a dream. For in the first place many persons 17
have in sleep the power, in some form or other, of
perceiving sound, colour, flavour, or touch, although the
sensation is weak and seems to come from afar. Persons
who are asleep and open their eyes slightly, and then
suddenly awake, have discovered the reality of the
lamplight, which in sleep they saw only, as they thought,
in a glimmer, and hearing the faint crowing of a cock, or
the bark of a dog, they have, on waking, recognised them
as loud voices. Some persons even reply to questions. 18
For it is possible that when one or the other of these
states, waking or sleeping, is unquestionably present, the
other may be present to some extent. In these cases

1 One may see from this that Aristotle was a careful observer of
the phenomena of consciousness.

246 Aristotle's psychology deinsom.

there can be no dream, neither can such processes of real
thought as occur in sleep, along with fancies, be called

19 dreams.-^ But a dream is that form of imagination that
originates in the movement of sensation during the
sleeping state as such.

It has occurred in certain instances that men have

20 never in their lives known themselves to have a dream ;
462^ in other cases they have observed them when far

advanced in years without having noticed them earlier.

21 The reason why dreams do not occur in these cases
seems to be closely allied to the reason which prevents
their occurrence in children, and after eating.^ For
persons who are by nature so constituted that a large
amount of vaporous-matter ascends to their upper parts, or
the return of this matter produces in them great move-
ment, it is reasonable to suppose that in these cases there

22 are no dream-fancies. In advancing years there is nothing
remarkable in the fact that dreams make their appear-
ance. For where a certain ([physical]) change takes place,
whether owing to age or to some internal affection, this
changed condition ([regarding dreams]) must also occur.

1 The cases in which one distinguishes an actual external stimulus
are not properly dreams.

2 The question whether or not there is dreamless sleep is not a
settled one (cf. James, Principles of Psychology, vol. i. p. 199 ff. )•
Hammond, Sleep and its Derangement, pp. 108 ff. The Cartesians,
consistently with their definition of mind as a thinking entity,
deny the possibility of a lapse of consciousness. Owing to its
nature mind must always think. Kant says: '*One can regard it as
certain that there can be no sleep without dreaming, and whoever
says he has never dreamed, has only forgotten his dream." Anthro-
pologie, 4te Aufl., Leip., 1833, p. 105. The disposition of modern
psychologists is to regard dreamless sleep as probable, but the question
is not likely to be removed from the region of dispute. Cf. Wundt,
Human and Animal Psychology, Eng. Tr., p. 324.

ON PROPHECY IN SLEEP.

CHAPTER I.

Regarding prophecy in sleep and the prophecy said to
be derivable from dreams/ it is difficult either to treat
it with contempt or to believe in it. For the universal 2

^The attitude of Aristotle towards the widespread belief in the
mantic character of dreams is marked by judicial fairness. He finally
concludes, however, that where dreams have been found to be pro-
phetic, this is due merely to accident. Belief in them prevailed and to
a certain extent continues to prevail amongst all nations, and is attested
by all literatures from the earliest times (cf. Tylor, Early History of
Mankind^ 3rd ed. p. 6 ff. ; Primitive Culture, 3rd ed. vol. i. p. 121 ff. ).
"All argument is against it; but all belief is for it," as Tylor
(vol. ii. p. 24) quotes from Dr. Johnson. This very accurately
represents the state of Aristotle's mind toward the prophetic character
of dreams. Greek literature especially is full of references to mantic
dreams, and the general soothsaying usages in Greek religion fostered
belief in them. Oneiros (Dream) is sometimes called a god {II. ii. 6),
again the messenger of Zeus, and Hesiod [Th. 212) tells lis that
dreams are the children of Night without a father, and the divine
origin of dreams is witnessed to by Socrates {Crito, 44 a) and Xenophon
{Anah. iii. 112). Aristotle belonged to the same intellectual era as
Socrates and Xenophon. We find a similar belief in the prophetic
nature of dreams witnessed to by the Hebrew Scriptures and the New
Testament {Gen. xxviii. 12, xl, 5-21 ; Numbers xii. 6 ; Matthew i. 20).

247

248 Aristotle's psychology dedivin.

or widespread belief in the prophetic nature of dreams,
based as it is on experience, lends support to this view,
and it is not incredible that certain events are foreseen
in dreams. There is a certain reasonableness in this,
and so one might, in like manner, apply this belief to

3 other dreams. The fact, however, that one cannot dis-
cover any intelligible cause for their occurrence, creates
distrust in them. The theory of divine origin is absurd,
because in addition to its irrationality, one observes
that these dreams do not come to the best and wisest,

4 but to all sorts of men. But when their divine causa-
tion is excluded, there is no other reasonable origin that
one can assign. For it seems to transcend our power
of understanding to discover an explanation of the story
that certain persons foretell the future through legends
on the pillars of Hercules or on the Borysthenes. Dreams,

5 taken either in their entirety, or partially, or singly,
must then be causes or signs of events, or else they

6 must be accidental phenomena. ' Cause ' I understand
in the sense of the moon's being the cause of the sun's
eclipse,^ and fatigue being the cause of fever ; by ' sign '
I mean e.g. that a sign of an eclipse is a star's becoming
visible in daylight or the roughness of the tongue in
fever ; by an ' accidental phenomenon ' I mean e.g. that
an eclipse of the sun happens while one is taking a

463 a walk. For taking a walk is neither sign nor cause
of an eclipse, neither is an eclipse the sign or cause

7 of taking a walk. Consequently no accidental pheno-

^Cf. Anal. post. 98& 1, 99a. 1 fF. Cause contains inherently the
explanation of a result ; sign is merely a concomitant or a precursor,
and has only an accidental relation to the result.

oiiAi'. I. I'KOniKriC DKKAMS 249

menon takes ])lace couHtantly or even as a rule. Is
it, then, possible that some dreanis are causes and others
sij^ns, ejj. of physical events? Well-educated physicians,
at any rate, say that we should pay close attention to
dreams. And this view is also regarded as reasonable
by laymen who are investigators and philosophers. For
the psychical movements that occur by day, unless they g
are very full and vigorous, are unnoticed when they are
experienced along with greater waking excitations. In
sleep, however, the reverse is true. For then the
trivial movements seem to be the important ones, as 9
is apparent from frequently observed facts regarding
sleep. When slight noises fall upon the ear one thinks
it lightens and thunders, and when a bit of mucus
flows into the mouth one thinks one is tasting the
sweet flavour of honey, and when a very slight heat
is felt in any member one thinks one is walking through
fire and is fever-hot. But when one awakes one dis- 10
covers the real facts. Since, then, all beginnings are
small, it is evident that the beginning of disease and
other bodily affections on the point of development will
be small, and these necessarily show themselves more
in sleep than in the waking state. Yet it is really n
not unreasonable to suppose that certain sleeping fancies
are causes of actions peculiar to the individual. For
when we are on the point of doing something or are
in the midst of it or have accomplished it, it frequently
happens that wre are occupied and busy with the same
thing in a distinct dream (the explanation of which is
that the dream movement has been already started
from origins in the day's activity); and as this is true,

250 Aristotle's psychology dedivin.

so the converse must be true, viz. that the movements
in sleep are often the starting points for the activities
of the day, because the thought for the latter is already

12 started on its way in our nocturnal fancies. In this
sense, therefore, certain dreams may be signs and causes.
But most prophetic dreams are things of chance, especi-

463 b ally all those that transcend us and whose origination
is not in our power, as e.g. a naval battle and remote
events. The situation here is just like that of a man
who thinks of a thing and in that instant the thing
appears. For what is there to prevent this being also
true of dreams ? It is even more likely that many

13 accidents of this sort should occur here. Just as, in
the former case, thinking of a thing is neither sign
nor cause of the thing's appearing, so here the beholder's
dream is neither sign nor cause of the event, but only
accident. Consequently most dreams do not come true.
For chance is that which occurs neither constantly nor
even as a rule.

CHAPTER II.

Since other animals^ than man have dreams, one may
say, in a word, that dreams are not sent from God and
do not occur for his ends. They are, however, daemonic.
For their nature is daemonic, but not divine. This is 2
proven by the fact that very ordinary men have pro-
phetic visions and true dreams, showing that God does
not send them ; but such men as have a loquacious and
atrabilious nature see all sorts of visions. And because
these excitations are many and diversified they chance
upon thoughts which correspond with reality, hitting
the right thing here just as one sometimes hits in the
game of " Odd and Even." ^ For in this instance the
proverb applies : " Who often shoots will sometimes hit."

^ " Quippe videbis equos fortis, cum membra iacebunt,
In somnis sudare tamen spirareque semper
Et quasi de palma summas contendere viris,
Aut quasi carceribus patefactis
Venautumque canes in molli saepe quiete
lactant crura tamen subito vocisque repeute
Mittunt et crebro redducunt naribus auras."

— Lucretius, De rer. nat. iv. 987 ff.

2 Read Bekker's conjecture dpndfoi'Tes instead of dprta /jLepi^ovres.

251

252 Aristotle's psychology dedivin.

3 That many dreams do not come true is not strange. For
even the signs in physical and heavenly processes, such
as the signs of rain and wind, often fail. For if another
movement sets in which is stronger than the one indicated,
the indicated event does not take place. Also many well-

4 matured plans of what ought to be done fail of execution,
because other more important motives arise. For not
every expected event occurs, and one must not identify
the future with the expected.^ Nevertheless one must
say that there are certain causes to which this lack of
fulfilment is due, and these are natural signs of the

5 non-occurrence of the given events.

In regard to dreams which are not due to such origins
464 « as we have mentioned, but to origins that either in point
of time, place, or magnitude are extraordinary, or which
are not to be described in this way at all, and yet the
dreamer does not have in himself the cause — in these
cases, unless the prophetic character is accidental, it
would be better to explain such foresight in the following
way, rather than in the way employed by Democritus,^

1 'Eo-6ix€vov signifies the future absolutely and /xiWov the future con-
tingently. Cf. De gen. et corr. 3,376 6.

2 Democritus explains dreams by the same principles — images and
effluxes — that he employs in the explanation of sensation. The images
(ei'SwXa, simulacra) thrown off by things are complexes of atoms, which
represent not merely the form, but also the inner qualities of things.
They are the things in miniature, and are capable of conveying psychical
processes, as well as physical features, from one person to another.
Mind has an atomic composition, and it is owing to this fact that the
opinions and feelings of friends are conveyed to us by their dream-
images. Prior to Aristotle almost all philosophers, like Democritus,
sought for an explanation of dreams outside the dreamer, dominated, as
they were, in greater or less degree by contemporary superstition. Cf.
Cicero, De, divinat. i. 43 ; Plutarch, De plac. phil. v. 2, Qiiarst. con.
viii. 10.

<;iiAi-. 11. POWKR OK IMIKVISION 253

wlio ex[)lains Uunii l»y iiiniL^'cs and cIlIuxeH. JuHt as when 6
wator or air is stirred, tlie sliiicd pait sotH anoUier jKirl
ill motion, ami wWvi this Iwih coiik; to rt^st a HJinihir
motion is contiinicd up lo a cc'ilaiii point, vvcn in th(*,
ahsenci^ of the ni(>viii<; a^'cnl, so nothin<^ ])revents a
certain iiiovcnu'iit and sensation from reaching the houI in
sleep, produced hy those ()l)j('('ts from which Democritus
says images and clUnxcs are thrown off. And these
movements, reaching the soul in some way or other, are
more distinctly felt at night, hecause they are more
readily dissipated when they enter by day (for the night
air is less apt to be disturbed owing to the calmer nature
of night), and they awaken sensation in the body on
account of sleep, for persons when asleep detect slight
internal processes more sharply than when awake. These 7
movements awaken fancies, out of which one foresees the
future in events similar to the fancies. This power of
prevision, then, occurs in any ordinary person, and not in
the wisest. For if prevision were sent of God, it would 8
come by day and to the wise. In this manner, however,
it is reasonable that prevision comes to ordinary men.
For the minds of such persons are not given to careful
thought, but are, as it were, reft and empty of all content,
and when stimulated they follow the lead of the moving
agent. The reason why certain persons afflicted with 9
ecstatic mania have prevision is that their own excitations
do not distract them, but are rather thrown off by them,
and, therefore, they have especial perception of processes
foreign to them. That some persons have true dreams, 10
and that familiar acquaintances have prevision especially
regarding each other, comes from the fact that acquaint-

254 Aristotle's psychology dedivin.

ances concern themselves most about each other. For just
as it is most true of intimate friends that they recognize
and see each other at a distance better than others do, so
it is also with these movements. For the movements of

11 acquaintances are more easily recognized. The atrabilious,
like long-distance throwers, owing to the vehemence of
their natures, hit their aim. And owing to their mobile

464 b disposition they have a quick fancy for sequence. For as
Philaegides^ in his poems and insane persons recite and
think out sequences that depend on similarity, as illus-

12 trated in the song of Aphrodite, so these dreamers string
together a series of events. For owing to their passionate
nature they are not swerved aside by extraneous move-
ments.

The most skilful interpreter of dreams is he who
can discern resemblances. For a plain dream can be
interpreted by anybody. By resemblances I mean,
as I said before, that the pictures of imagination

13 are very like pictures in the water. In the latter,
when the movement is violent, the reflection and
picture bear no resemblance to the reality. And so a
clever interpreter is one who can quickly distinguish
and see at a glance in the confused and distorted
picture the suggestion of a man, or hprse, or whatever

M the given object may be. And as the picture in the
water, so the dream can be similarly distorted, for

^ Philaegides is an unknown poet. Leonicus (quoted by Barthelemy-
St.-Hilaire, Comment, ad loc.) conjectures Philaenis, a Greek poetess
of Leucas, contemporar}' of the sophist Polycrates, to whom an
obscene poem on Love was ascribed. Michael of Ephesus {Gommeni.
ad loc. fol. 1527, p. 48) repeats the name Philaegides, as given in the
text.

oiur. 11. IN'rKIUMlK'I'A'I'ION 0[.^ DRKAMS 2R5

inoveiiunit destroys tho distinctiioss of (ircarns. We
have now ('xpliiincd the nature of sleep and drearna,
and have j^iven l\w. eanse of tluMr oc(;urrence, and have
further exj)hiined the entire suhject of divinaticn hy
means of them.

ON LONGEVITY AND SHORTNESS
OF LIFE.

CHAPTER I.

We^ must now inquire into the causes why some
animals live long and others only a short time, and
into the general subject of longevity and shortness of

2 life. The initial point in our inquiry must be the
stating of certain preliminary problems touching these
phenomena. For it is not clear whether or not the
cause of longevity and shortness of life is the same in
animals and plants. Some plants are annuals, and

3 others attain great age. Further, one may ask whether
amongst the creatures of nature the long-lived and the
naturally healthy are identical. Or is shortness of life
to be kept distinct from questions of disease ? Or is it
true that some diseases cause the body whose nature is
affected, to be short lived, while other diseases in no wise
prevent long life ?

^ I have removed the brackets from the passage 464ft 19-30, being
unable to see any good reason for following Biehl in regarding it as
an interpolation.

256

rnAi-. r. THM 'I'KNUKK OK LIKK 267

Regarding Hlcopiiij^' uiul wjikini^ wi; hav(^ alnwly 4
spoken, and vvi^ iiiu.st laid- on treat the subjects of
life and death, and likewise disease and health, so far
as they fall within the province of the philosophy of
nature. At present we have to consider, as aln^ady 465 a
said,^ the causes of lon<;evity and shortness of life. 'J'liis
distinction of longevity marks entire genera in comparison
with others, and again it marks certain mendjers of one
species in comparison with other members. By this 1 5
mean there is a generic difference in longevity applicable
e.g. to man and horse (for the genus man is longer lived
than the genus horse), and again within the species one
man is loncjer lived than another. For some men are
long lived and others short lived, according to the
districts they inhabit. Nations that inhabit warm
countries live longer ; the inhabitants of cold countries ^ 6
are less lomTj lived. And amongst those that inhabit the
the same locality there are also between individuals
differences in this respect.

^ Retain the reading KaOdirep, k.t.X. (465a 2) bracketed by Biehl.

^ This statement is not borne out by statistics, at least under
present conditions. Nevertheless the statement may have been
correct in Aristotle's time. Inasmuch as the North Countries were
then inhabited by people of inferior civilization, it is likely that
the period of life was less than it is now under conditions of higher
civilization. The more civilized races protect the aged, and so
contribute to longevity, besides being generally better equipped with
means and methods for self-preservation. Cf. Lankester, Comparative
Longevity, p. 107 ff. ; Van Oven, Decline of Life in Health and Disease,
pp. 60, (51.

R

CHAPTER II.

We must understand what is easily destroyed in natural
structures and what is destroyed with difficulty. Fire
and water and other elements akin to them, without
having their power, are, in their reciprocal action, the
causes of generation and decay. Consequently, everything
else, one may reasonably suppose, that is derived from or
composed of these elements, shares in their nature, except-
ing such things as are artificially composed of a great

2 many parts, like a house. The discussion of these other
elements does not belong here. Many things are subject
to destruction from causes peculiar to themselves, as e.g.
knowledge, health, and disease. For these are destroyed
when the things of which they are qualities are not
destroyed but survive, e.g. the agency which destroys
ignorance is recollection and learning ; the agency which
destroys knowledge is forgetfulness and error. Acci-

3 dentally, the destruction of other properties goes hand
in hand with the destruction of the natural body. For
when animals are destroyed the knowledge and health

4 that are in them are also destroyed. From this one
might draw a conclusion regarding the soul. For if

258

<;iiAi. II. CAUSKS OV DKSTRUCmON 259

the soul is not in the body by iiiitunil [frowth, hut is
there just as knowledge is in the soul, then it would be
exposed to another destroying agency in addition to that
to which it is lia))le in the destruction of the body.
But this does not appear to be the case ; the relation
between soul and body must be differently understood.

CHAPTER III.

465^ Perhaps one might reasonably ask the question : Is
there any place where the perishable is imperishable, as
in the case of fire in the Empyrean, which is subject
to no opposing influence ; for the properties that attach
to opposites are incidentally destroyed by the destruc-
tion of the thing itself. For opposites destroy one
another. No opposite, however, which belongs to sub-
stance is incidentally destroyed, for substance is not

2 predicated of any subject. Consequently, in whatsoever
thing there is no principle of opposition, and where there
is no such principle, there can be no destruction. For
what is there to work destruction, if destruction is
effected exclusively by opposites ? But there is no op-
position present, either absolutely or in any particular
part. Or is this true in one sense and in another false ?
For whatever has matter cannot avoid being in some

3 sense subject to opposition. It can be everywhere hot
or straight, but it cannot be in its entirety hot or
straight or white. For these qualities would then be
separate entities. Whenever the active and passive
come together, if the one always acts and the other

4 is always acted upon, change must take place. Further,

260

oiiAr. III. I'lUNCII'LKS OK DKSTIUJCTION 261

if change necessarily produces a residue, then residue
involves opposition. i^'oi- change- is always the result
of opposition, anil residue is that wliich remains from a
state prior to change. But if the actually opposed were
entirely excluded, a thing would, in this case, be im-
perishable.^ Or is this untrue, ])ut a thing in this event
would be destroyed by its environment? If this happens, s
then the above explanation is adequate.^ If the destruc-
tion is not so produced, one must suppose there is an
actual inherent opposition in the thing, and that a
residue is produced. For this reason the lesser flame
is incidentally consumed by the larger one, because the
food which the smaller one consumes in a long time
in the form of smoke, is consumed by the larger one
quickly. And so everything is in constant motion,
constantly coming into existence and passing out of
existence. And the environment either assists or opposes. 6
Constantly changing things may last a longer or a
shorter time than their own nature prescribes, but
nothing lasts for ever, where opposites exist. For at
the very start, matter contains in itself the principles
of opposition, so that if one employs the category of
place, spatial change is involved ; if one employs the
category of quantity, we have changes of growth and
decay ; if one employs passivity, then qualitative change.^

^ That is, if the principle of opposition were excluded there would be no
change, and if there were no change, a thing would be indestructible.

2 The environment, in that case, would supply the principle of
opposition, and so the dogma of "no opposition, no destruction"
would remain unchallenged.

•^In other words, the whole of the terrestrial world is subject to
corruptibility and change {Metaph. 1035a 25, 10696 24; De coelo
283« 30).

CHAPTER IV.

466 a Neither are the largest creatures less exposed to de-
struction than others (for the horse is shorter lived than
man), nor the small animals (for many insects live only
a year), nor, in general, are plants longer lived than
animals (for some plants are annuals), nor are sanguineous
animals, by virtue of their being sanguineous, long lived
(for bees live longer than do certain sanguineous
animals), neither are the bloodless animals, as such,
long lived (for molluscs, which are bloodless, live only a
year), nor land animals (for there are both plants and
land animals that live only a year), nor sea animals (for
2 the crustaceans and molluscs are short lived). On the
whole, the longest lived organisms are found amongst
plants, an example of which is the palm.^ Next the
sanguineous live longer than the bloodless animals, and
the land animals longer than those that live in water.^

^ Apart from the age attained by man, and by certain insects and
plants, little is accurately known about the longevity of organisms
(Lankester, op. cit. p. 12).

'^ Dr. Gunther (quoted by Lankester, op. cit. p. 13) says : " There is
scarcely anything positive known of the age and causes of death of
various fishes," but cases are reported of carp attaining the age of 150

262

(HAP. IV. DURATION OK lAVK 263

So tlijit l\w. l()n^(^Ht lived MiiiiiiiilH aro those where we
find tho (joinbiiKHl iiuirks of havin<^ blood and liviiij^ on
the hind, as instanced in man and the eh^jhant.^ It is a 3
rule also that the larj^an- animals are longer lived than
the smaller ones. And this characteristic of size applies
to other examples of longest lived animals, as well as
to the instances cited.

years, and pike 267 years (!) and elephants are reported to have lived as
long as r)00 years {ih. p. 59), but the statements are not proporly
authenticated. Trees arc reported to have attained ages ranging from
335 years (Elm) to 3200 years (Yew), and even to above 4000 years
(Taxodium). In the Popular Science Monthly (vol. ii. p. 250) the story
is told of a carp killed at Chantilly aged 475 years. Weismann says
that large trees have the longest life of all organisms in the world, and
the "largest animals also attain the greatest age . . . and it would not
be difficult to construct a descending series of animals, in which the
duration of life diminishes in almost exact proportion to the decrease
in the size of the body." Essays upon Heredity, Eng. Tr., p. 6. A
general rule such as this would, of course, have many exceptions, as e.g.
in the case of the eagle and horse, the former being inferior in size but
superior in longevity.

^ Aristotle reports the age of an elephant at 200 years, or, according
to another report, at 120 years, for his statement is made only on
hearsay {ol ixiv (pacn, Hist. anim. 6306 23).

CHAPTER V.

The cause of all this might be discovered in the following
facts. One must understand that an animal is by
nature moist and warm, and life is also moist and
warm, whereas old age is dry and cold, and so is death.
And this is plain to observation. The matter in living
bodies has these qualities of warm and cold, dry and

2 moist. As beings grow old they must then dry up, and
so the moist should be constituted in such way as not to
dry up easily. Now, fatty elements do not readily
decay. The reason is that they contain air, and air
compared with other elements is fire. But fire is not
subject to decay. The amount of moisture should not
be small, for a small amount is quickly dried out.

3 Consequently, larger animals and plants are, as a rule,
longer lived than others, as we said before. For it is
reasonable to suppose that the larger creatures possess a
greater supply of moisture. But it is not merely for
this reason that they are longer lived, for there are two
causes of long life, a quantitative and qualitative cause-
Consequently, there must not merely be a certain quantity
of moisture present, but this must also be warm, in order

264

<;iiAi'. V.

CAUSKS OK I.ONC \AVK 265

that it 1x5 not easily (•oiij^ouluil or ilricid u|). It is for 4
this reason that iniin is hunger lived than curtain hirger
animals. For animals that are defective in the mass of
moisture arii h)n«jfer lived, provided their excess in tlie a(>(^^
quality of this moisture is relatively <,'reator than their
defect in its ([uantity. Some animals have an oily
warmth, in consequence of which their moisture is not
easily dried up or chilled. Others again have a moisture of
a dillerent sort. Further, whatever is meant to be diflicult 5
to destroy should not throw off much residue. For this,
whether it be due to disease or to nature, destroys a
thing. Kesidue has the significance of opposition and is
destructive of a thing either in its entire nature or in
some part of it. Consequently, salacious animals and
such as abound in seed age quickly. For seed is a
residue and when it is thrown off produces dryness. For 6
this reason a mule lives longer than a horse or an ass,
and women live longer than men, in cases where men are
lascivious. And so male sparrows are shorter lived than
females. Further, males subjected to hard labour are
short lived, and on account of toil age more rapidly.^
For toil produces dryness, and old age is dry. In the 7
ordinary course of nature, and taking it all in all, men
live longer than women.^ The reason for this is that
the male is a warmer animal than the female. The same

^ Excessive expenditure in organic metabolism due to labour, violent
activity, inordinate eating, etc., on the one hand, and waste in pro-
pagation on the other, reduce the tenure of life.

"^ Statistics show that females have a longer average of life than
males (Lankester, op. cit. p. 117). A writer in the Saturday Review
(vol. 79. p. 248) shows that in polygamous races, the males are shorter
lived than the females.

266 Aristotle's psychology de l. et b. vit.

classes of animals live longer in a warm than in a cold
climate, for the same reason that the larger animals

8 live longer than smaller ones. Particularly striking in
this connection is the size of the naturally cold animals.
So snakes, lizards, and rough-scaled reptiles found in
warm localities and the testacea of the Red Sea attain a
great size. For warm moisture is the cause of growth

9 and life. In cold districts animal moisture is more
watery and consequently easily congealed, so that
animals with little or no blood, whether their habitation
is the land or water, do not occur at all in the northern
regions, or if they occur they are smaller and shorter

10 lived. For frost impedes growth. Both plants and
animals perish when they get no nourishment, for then
they consume themselves. Just as a larger con-
sumes and destroys a smaller flame by using up its
food, so the natural warmth, whose primary function is
digestion, consumes the matter in which it is found.

11 Aquatic animals are shorter lived than land animals, not
because they are moist unqualifiedly, but because they

467 a are watery. Moisture of this sort is very perishable,
because it is cold and easily congealed. For the same
reason the bloodless animal is very perishable, unless it
is protected by great size, because it contains no oily or
sweet element. I say sweet, for animal fat is sweet.
Consequently bees are longer lived than other animals
that are larger.

CHArXKR VI.

It is amongst plants that we find the longest lived
organisms, and these attain a higher age than animals, in
the first place because they are less watery and therefore
not easily congealed. Secondly, they contain a viscous
oily substance, and therefore, although they are dry and
earthy, they nevertheless possess a moisture which is not
easily dried out. We must now find an explanation for 2
the great age attained by trees. For a peculiar explan-
ation applies to them which does not apply to animals,
excepting insects. This peculiarity is that plants con-
stantly renew themselves and so attain great age. For
new shoots are put forth from time to time and others
grow old. And the same thing is true of the roots.
But this renewal does not take place in all parts at 3
once ; sometimes only the trunk and branches die and
others grow up alongside of them. And when this
happens other roots spring from the remaining part. And
so it continues, one part passing out of existence and
another part coming into being. Consequently, they live 4
long. Plants have a resemblance to insects, as already

said. For life continues when they are divided, and out

267

268 Aristotle's psychology del. etb. vit.

of one insect or plant two or several are produced.
Divided insects, however, reach merely to the state of
living, but are not able to continue long in life. For
they have no organs, and the principle of life in the
single part has no power to develop an organ. This
principle in the plant, on the contrary, has the power of
developing organs, for it contains in every case both root

5 and stem potentially. Consequently, the new and the
ageing branch keep growing from this, differing little in
their length of life, just as it is with grafts. In the
grafting of shoots, one would say that in a certain sense
this same process occurs, for the shoot is part of a
plant. In the grafting of shoots, however, the conti-
nuity of life occurs in a state of separation from the
mother plant, while in the other cases the lives are

6 conjoined. The reason is that the inherent potential
principle in the plant is all-pervasive.

There is, however, a point of identity between animals
and plants. In animals the males are, as a rule, longer
lived than the females. For their upper parts are larger
than the lower ones (the male is more dwarflike ^ than
the female) ; the warm element is found in the upper

7 parts and cold in the lower ones. Also plants with
467 b large roots are longer lived than the others. Annuals

are not of this kind, but trees are. For the upper part
and head of a plant is the root, but annuals have their
main growth towards the lower ^ parts and the fruit.

8 These questions will be examined in detail in the treatise

^ That is they have larger heads and shoulders.

' Viz. towards the branches, which are analogous to the lower parts
of man.

(irAi. VI. (M)MI»AKA'riVK L()N(;KVITY 209

On IVanU} V\)y iIk^ prcscnl vv(^ hiivi? (jxpljiinod \\\v.
cause of loiij^ovity juul .sliortncHs of \'\U\ in juiinial.s.
There roniain for our conHidcnition the, suhjecLs of
Youth and OKI A<,% Liln and DciiiLli. And after these
have heeu iuvivsti^^Mted, our treatise on animals'^ will
have been tinished.

^ The two books of Ariatotlo {llixt. an. /)39a 20, De gen. an. 710a, 1),
irepl (pvTiOf, appear to have been still in existence at the time of
Horniippius, but to have been (inally aupplanted by the completer work
of Thoophrastus on the same subject. Cf. Zeller, Philoiophie d. Griech.
Th. II. Abth. ii. 3te. Aufl. p. 98.

^ Owing to this statement Brandis (Jfandbuch d. (hachichte d. Philon.
p. 111)2, 98) thinks that only the iirst five tractates of the Parva
natnralla were written immediately after the De anima, while the
three following (viz. On Longevity and Shortness of Life, On Youth
and Old Age, and On Resjnration) were written after the comi)lction of
the treatises on Zoology. There is no reason why this should not be
true, although proofs from cross-references in Aristotle's writings are
never very cogent for their chronology, such references being often a
later addition. It frequently happens that the treatise X cites the
treatise Y, and the treatise Y cites the treatise X, such additions and
references (particularly when at the beginning or end of a work) being
added often by an editorial hand. The Topics, e.g. quotes the
Analytics {Top. 162a 11, 1656 8), and is quoted by the ^naZy^ics (^n.
prot. 246 12, 64a 37, 656 16).

ON YOUTH AND OLD AGE, AND ON LIFE

AND DEATH.

CHAPTER I.

We must now treat of youth and old age, and of life and
death. At the same time it may be necessary to explain
the causes and conditions of respiration. For in some
animals^ life and death are conditioned by respiration.

2 We have elsewhere treated more precisely of the soul,
and it is clear that its ultimate nature cannot be corporeal,
although it has its seat evidently in some part of the
body, and in some part, too, that has a higher importance
amongst the body's members.^ For the present we must

3 dismiss the other parts or powers of the soul (whatever
may be the proper term to apply ^ to them). In regard to

^ Only animals endowed with lungs or analogous organ may be said
to respire. The employment of water by fishes serves a similar purpose
(refrigeration or regulation of temperature), but is not respiration. In
such animals as respire, life and death are conditioned by the perform-
ance of this function.

^In the heart.

3Cf. De an. 414a 30 flf., 433?> 1, 415a 25, 416a 20.

270

i'llAI'. I.

F.IKK AND SKNSA'noN 271

creatures iJial. arc Icnncfl animals and have life, in Cftses
where they arc cndowrd vvilh l)(>lh attrihiilcH — I mean
with aiiiniality and life — it nniHl, be that the principle
whereby they live, and l»y virtue ot which they are called
animal, hIiouUI he onv. and th(^ same j>art.^ For it is 4
impossible for an animal as animal not to have life.
On the other iiand, it is not necessary for a thing to be
an animal because it has life. For plants live, and yet
they have no sensation, and it is in terms of sensation
that we distin<jjuish the animal from the non-animal.
Numerically they are one and the same part, althou<^h in
their mode of expression they are manifold and different.^
For it is not the same thing to be an animal and to have
life. Since amongst our sense-organs there is one which 5
we call a kind of ' common sense,' where all our actual
sensations must come together, this ' common sense ' must
occupy a position midway between what we call the anterior
and posterior parts of the body (by anterior^ is meant that
which is situated towards the region of sensation, and by
posterior that which is situated in the opposite region).
Furthermore, since in all living organisms the body is
divided into an upper and lower half (for all animals as
well as plants have an upper and lower part), the nutri-
tive principle should evidently* occupy a position midway 468 <?

^ I.e. nutrition and sensation are functions of one life-principle.

^ The fundamental mark of a living thing is the power of nutrition and
propagation ; the fundamental mark of an animal is sensation. Both of
these functions in the animal are performed by the central organ.

^By anterior is meant upper, i.e. towards the region of the senses,
which are mainly about the head.

^ Aristotle assumes this, of course, owing to his teleological view of
nature. Nature operates in the way that is best.

272 Aristotle's psychology dejuvent.

between them. The part which contains the organ for
admitting food is called the upper part, and we use the
term ' upper ' here in reference to the body itself and not
in reference to the directions of the surrounding universe;^
by * lower ' we mean the part whose primary function is

6 to void excrement. In this connection we find a wide
difference between plants and animals. In man more
than in any of the other animals, owing to his erect
attitude, we find the upper part turned towards the upper
part of the universe; in the other animals^ the upper
part is turned in a direction midway between the upper
and lower parts of the universe ; in plants, which are
fixed on one spot and draw their nourishment from the
earth, this upper part must in every case have a down-

7 ward direction. For roots in plants and mouths in
animals are analogous organs, by means of which in
the one case food is derived from the earth, and in
the case of animals through themselves.^

^ Upper in reference to the universe signifies the direction in which
flame and light substances move (cf. Phys. 2006 19, Metaph. 1065b 13).

^ Cf. Sallust, De conjur. Cat. i.

3 Animal food in its final form is, in Aristotle's theory, the blood.
Cf. De somiio, 456a 34 ; Dejuvent. 469a. 1, 32 ; De part. an. 678a 6.

CHAPTER II.

All perfectly developed animals are analysable into
three parts — one for the admission of food, a second for
the voiding of excrement, and a third midway between
these two. The last of these is called in larger animals
the chest, and in the smaller some equivalent term
is used ; ^ in some animals, however, it is more clearly
articulated than in others. Again, such animals as are 2
capable of progressive motion have, in addition to the
parts mentioned, other organs adapted to the service of
movement and to carrying the entire trunk — as legs,
feet, and other organs that have the same function as
these. The nutritive principle of the soul is situated in 3
a region central to these three parts, as is evident both
from observation^ and reason. In fact there are many
animals which, after one or the other part has been
cut off, even the head and the organ for seizing food,

^ The general thoracic region.

2 That is, on empirical and a priori grounds. If this central situa-
tion is the best for the performance of functions in which the entire
body is interested, then it is reasonable to suppose, Aristotle says, that
nature has placed the nutritive principle here.
S 273

274 Aristotle's psychology dejuvent.

continue to live in that part to which the middle is

4 conjoined. This fact may be plainly observed in the
case of insects, such as wasps and bees. Also many
animals besides insects, when cut in two, can continue
to live by the functioning of the nutritive principle.
This nutritive part is actually unitary, but potentially
multiple, and the natural construction of these animals
is the same as that of plants. For plants after they are
divided continue to live in segments, and from a single

5 origin one can by section produce several -^ trees. Why it
is that some plants cannot continue life after section, while
others can be propagated, must be explained elsewhere.

468^ In this respect, however, plants and insects as a class are
alike. It is necessary that the nutritive principle in
those living things that possess it ^ should be actually

6 one, though potentially multiple. And the same holds
good of the principle of sensation ; for the segments
evidently have sensation. In reference to the main-
tenance of their natural life, plants ([when divided]) are
able to survive. Animals are not, for they lack organs
for their preservation, wanting in some instances organs
for the seizure of food, and in others for receiving it into
the body, and in other instances wanting other organs in

7 addition to both of these. Such divisible animals

^ In the lower forms of animal life, as in vegetable life, organic
functions are less centralized than in higher orders. In all of them,
however, there is a certain amount of centralization, and even in insects
life continues only a short time in any member after severance from the
middle segment. Cf. above, 467a 20 ; Hist. an. 5316 30 ff. ;
De an. 4116 23.

2 Ogle, in his translation of this tractate (London, 1897, p. 109)
suggests for ^x°^<^'-^i ivrd/j-ois. Cf. , however, 479a 8, where we have the
same use of toIs ^x^^^****

<MiAi-. II. UNITY OK LII''IC-I'KIN(.'IIMJ': 275

rosoiiiblo II coiupUix of Hcvoral civaLun\s i^rown to^'CitlitT.
Tn tho most perfectly or^Miuized b()(li(^s, howevc^r, tliis
plienoinoiion is not found, because their natures have b(;eri
fashioned into the greatest possible unity. There are
always, however, certain dissected members which exhibit
slight sensation, because they are still under the influence
of a certain psychical ^ affection. For after the entrails
have been removed, bodily movements are still continued,
as one observes in tortoises after the removal of the
heart.

^ Aristotle know nothing of the nature of reflex-movements, having
no knowledge of tho nervous system and regarding the heart and not
tho brain as the centre of psychical life. James ( Principlefi,
vol. i. p. 16) cites the case of Robin, who, on tickling the breast
of a criminal an hour after decapitation, saw the arm and hand
move towards the irritated point. Ogle (op. cit. p. 109) says that
"insects, such as grasshoppers, from which the viscera have been
•entirely removed and replaced by cotton-wool as entomological
specimens, if not pinned down, often fly away."

CHAPTER III.

We have further proof of the central situation of the
nutritive principle in the case of both plants and animals.
In the case of plants we observe their generation from
seeds, and we also note the phenomena of grafts and

2 slips. Generation from seeds takes place in every
instance from the centre. All seeds are bivalvular, and
the point at which their two halves are joined is the
point from which generation begins and the middle in
reference to the two parts. It is from this point that
stem and root shoot forth in growing plants, and the

3 point of origin is also the central^ point. This pheno-
menon may be observed in the case of the buds of
grafts and slips, for the bud is in a sense the life-principle
of the branch and at the same time its centre. It is the
bud, therefore, which one removes or into which one
inserts a graft, in order to produce branch or root from
it, on the theory that the origin of life in branch or root

^ Similarly Aristotle regards the heart or animal centre as the part in
which life originates, and notices that it is visible in very small aborted
embryos, and is observable in the egg on the third day {De part, an,
665/> 1).

276

oiiAi'. III. DKVKLOPMKNT OT LIKK li77

is the contrii. In siin«^qiiiio()UH jiniiiiiily lint lirnL or^'aii in 4
development i.s tlu? heart. 'I'his in plainly seen in
those animals whose process of generation admits of
observation. In bloodless animals the organ that
is analogous to the heart must be the first de-
veloped. We have already said in our earlier treatise, S
On the rarts of Animah} that the heart is the organ
from which the veins proceed, and that the blood in
sanguineous animals is the ultimate source of nourish- 469 «
ment, out of which the members are generated.^
Although regarding nourishment it is plainly the office 6
of the mouth to perform one certain task, and the
office of the stomach to perform another task, yet the
heart is the master-organ and sets the end for all
the others. Consequently, in sanguineous animals it is 7
in the heart that we must look for the origin of
nutrition and sensation. For regarding the preparation
of food, the functions of the other organs are subordinate
to the function of the heart. It must be true that
the master-organ is that which works persistently
towards the end and does not stop with that which is
subordinate to the end, just as a physician persistently
works towards health. At any rate, the dominating 8
organ of sensation in all sanguineous animals is found
in the heart, for the ' common sense' which serves all
the special senses must be situated there. There are
two senses, taste ^ and touch, whose channels lead mani-

^ Z)e ^art. an. 665a 15.

- De scmmo 456a 34. Cf . also this tractate 469a 28 ff. ; De resp.
481a 11 ; De part. an. 678a 7 ; De gen. an. 740a 21.

^ Taste, as has been already said, is a sort of touch, and both taste and
touch are connected with the heart by means of channels {irbpoi), by

278 ARISTOTLE S PSYCHOLOGY de juvent.

festly to the heart, and what is true of these must he
true of the other senses. Movement in the other sense-
organs may be transmitted to the heart, but with the
upper parts of the body these two senses ([touch and taste])

9 do not communicate at all. Apart from these con-
siderations, if the life-principle in all animals is situated
in the heart, the sensory principle must evidently be
found there also. For that by virtue of which we call
a thing an animal is the same as that by virtue of
which we say that it lives, and the differential mark
of sensation is the same as the differential mark of a

10 living body. The reason why certain senses are, as we
see, connected with the heart and others with the head
(in consequence of which some philosophers^ regard
the brain as the organ of animal sensation), has been
given in a separate treatise.^

which Aristotle probably understood the veins diffused through the
flesh and leading to the central organ {De part. an. 656a 29). Their
medium is elsewhere described as the flesh itself [De gen. an. 744a 1).

^ Plato and Diogenes of Apollonia.

2 De part. an. 686a 5 fF.

CHAPTEK IV.

From what we have said, based on observed facts, it is
clear that the principle of sensation, as well as that of
growth and nutrition, is situated in this organ ([the heart])
and in the middle of the three divisions of the body. On^
the basis of deduction we should say the same thing,
because we see that nature, out of existing possibilities,
does in every instance the best. Now, if each
principle'^ is situated in the central section, the parts ^
(viz. that which finally elaborates the food and that
which receives it) would thus perform in the best
possible way their several functions. For to each of the
parts the central organ will then be so related as is best,
and the mid-position in a case such as this is the position

^ The editions of Bekker begin Chap. iv. here.

" Namely, the principles of sensation and nutrition.

^ Aristotle's meaning appears to be that if the nutritive principle as
well as the principle of sensation is lodged in the middle section, then
the two parts of nutrition, viz. elaboration of food and its assimilation,
would be best performed. In other words, the heart, as the organ of
nutrition, would in this way be best placed for preparing food for
distribution to the surrounding parts, and the surrounding parts, as
receivers (r6 8€ktik6v), would be best served by a centrally situated source
of supply.

279

280 Aristotle's psychology dejuvent.

469^ that naturally belongs to a ruling principle. Again, one

2 must make a distinction between the user and the instru-
ment used (and as they differ in function, so too, if possible,
they should differ in position), as a flute and the hand
that plays it are different in function and situation. If,
then, to be an animal means to have the power of
sensation, this power in the case of sanguineous animals
must be found in the heart and in bloodless animals in

3 a corresponding organ. Every member and the entire
animal body possess to a certain degree congenital
heat. Consequently we see that during life animals are
warm, but when dead and deprived of life they are cold.

4 The source of this heat in sanguineous animals must be
sought in the heart, and in bloodless animals in the
analogous organ. For all the organs (especially the
dominating one) prepare and digest their food by means

5 of natural heat. Consequently, all the other parts of the
body may become cold and yet life may continue, but when
the master-organ becomes cold, life is destroyed entirely,
because this is the source of heat for distribution to all
other organs, and the soul is as it were suffused with fire
in this organ, which in sanguineous animals is the heart,
and in bloodless animals an organ analogous to the heart.

6 Life, then, must go hand in hand with the continuance of
this heat, and what we call death is its discontinuance.

CHArTER V.

There are two ways in which, as we see, fire may be
extinguished, viz. it may either go out or be put out.
In the former case we say the extinction is caused from
within, in the other case it is caused by opposing forces ;^
an example of the former is old age ; of the latter,
external violence. Extinction in both cases, however, is
due to the same ultimate cause, viz. the failure of fuel,
for when fuel fails and the heart can no longer receive
sustenance, extinction of the fire ensues. Cold, by 2
retardinf]f dicfestion,^ arrests nourishment. And there
are times when it extinguishes itself, as, e.g.^ when the
heat is massed in too great quantity,^ owing to lack of

^In either case the extinction is due to the ascendency of cold over
its contrary heat. Only in the former case, according to Aristotle, the
extinction is due to the normal failure of fuel through exhaustion ; in
the latter case the extinction is due to unnatural or artificial exposure
to cold or wet (which Aristotle calls opposing forces), thus abnormally
checking the production of heat by the blood, and violently bringing
the supply to an end,

^Digestion {ireypLs) means * cooking.'

'Excessive heat is here conceived of as too rapidly exhausting the
supply of fuel, as in the case of fever or in old age (owing to its
diminished supply of fuel). In addition to this the lungs in old age

281

282 Aristotle's psychology dejuvent.

respiration or lack of cooling. And when the heat
accumulates in such mass, it soon causes an exhaustion of
fuel, and this process of exhaustion takes place before

3 evaporation has time to develop. Not only, then, is a
smaller fire extinguished by a larger one, but also the
flame of a lamp is consumed within itself when immersed

470a in a large flame, just as any other combustible would be
consumed. The reason for this is that the larger flame
uses the fuel contained in the smaller before other fuel
can take its place, and the fire continues in constant
process of development and in constant flow like a river,

4 but we do not observe this on account of its rapidity. It
is clear, then, that if the heat is to continue (and this is
necessary if life is to continue), there must be some

5 means of reducing the heat in the chief organ. An
illustration of this may be had in what takes place in
quenched coals. For if coals are kept closely covered in
a common oven, the fire is quickly extinguished.
Whereas if one in rapid alternation removes a lid and

6 sets it on again, the coals continue lighted a long time.
Covering a fire with ashes also keeps it. For owing to
the porosity of the ashes ventilation is not prevented,
and the ashes, by admitting the surrounding air, protect
the fire against extinction through excess of heat arising in

7 it.^ However, the explanation of the fact that opposite

become dry and hard, and do not so well perform their function of
regulating the temperature. Of. De respir. 4786 35, 479a 7 ; Meteor.
379a 5 ; De gen. an. 7836 7.

^ In other words, the surrounding air being admitted by the porous
ashes prevents the excessive heat within from exhausting its fuel.
Analogous to this is the reduction of the vital heat by the ventilation of
the lungs.

<'ll.\l'. V

EXTINCTION OF IIKAT 283

effects luo produced hy covi-riiij^' u lirtj with uhIius and vvilli
an ovcii-lid (for the latter extinj^uisJies it and the former
keeps it a lon^^ tinit;) has hoen given in our treatise
Ori Problems. '

' The (]U08tiou is not diHCUsaud iti tho extiiiit /'rohlenyt.

CHAPTER VI.

Since every living thing has a soul, and the soul, as we
have said, cannot subsist without natural heat, we find
that in plants adequate provision has been made for the
preservation of natural heat through nutriment and the

2 surrounding air. For food produces refrigeration in
organisms when it is first introduced, just as on its
entrance it does in man. Whereas fasting creates heat
and produces thirst. For air, when it is stagnant, always
becomes heated, but when set in motion through the
admission of food it is cooled, until the food has under-

3 gone digestion. On the other hand, if the surrounding
air is excessively cold, owing to the season and the occur-
rence of heavy frosts, plants are dried up, or if intense
heat occurs in summer and the moisture derived from the
soil is inadequate for refrigeration, the natural heat is
extinguished and destroyed. In such seasons one says

4 that trees are frosted or suffer blight. And that is the
reason why people pile certain kinds of stones ^ about the

^ Whether any particular variety of stone was used for this purpose is,
so far as I am aware, unknown. Presumably nothing more is meant
than that such stones were used as lent themselves to making a compact

284

niAP. VI. HK(JULATI()N ol" IIKAT 285

root.s or cover them with vessels of wuUt, in order to 47o^
keep the roots of tlie plunts cool. In the case of
aniinals, since some of them are aquatic and othcjrs live
in a medium of air, the refrigeration is derived from and
through the media in which they live, i.e. in the one case
water and in the other air. We must n(jw hcgin a
special incpiiry touching the nature and manner of this
process.

covering, thus shutting out the heat, or such stones as by their density
wrro poor conductors of heat. In any case the chief idea is that they
performed the same service as lungs and gills in animals, viz. the
service of refrigeration or the prevention of excessive heat, as Aristotle
supposes.

ON KESPIRATION.

CHAPTER I.

A FEW of the earlier physicists ^ have treated the subject
of respiration. But in regard to the purpose which it
subserves in the animal organism, some of them have
given no explanation whatever, and others, although they
have discussed it, have been wrong in their statements and
have lacked empirical knowledge of the facts. Further-
more, they declare that all animals respire.^ This, however,

^ Diogenes of Apollonia, who explained thought as well as life by
means of respiration (Zeller, Phil, der Oriechen, 4te Aufl. vol. i. p.
246), Empedocles (Burnet, Early Greek Philos. p. 230), Democritus
(Zeller, op. cit. p. 810), Anaxagoras (of. below 4706 20).

2 Aristotle confined respiration to the admission and expulsion of air
(4806 10). In modern Physiology, respiration in a wide sense includes
that form of internal respiration (properly a function of nutrition), which
means the interchange of oxygen and carbon dioxide between the cells
and the fluid that drenches them (cf. Ency. Brit. Art. on " Respiration ").
Ordinarily, however, it is used to signify the expulsion of carbonic acid
and the admission of oxygen, which is effected mainly through the
lungs, gills, skin, and alimentary canal. Pulmonary respiration is the
chief means of working this interchange, and it is to this that Aristotle's
opuscle is confined, referring to other means of respiration as only
analogous functions.

286

VMM'. I. I'lIKPOSK OK KKSIMKATION 2H7

is uiitiuo. It will l>o neccssury, t!i('r('fnn\ to ictuni lo 2
t-licsf points, in oidcr tliat vvc Im' not tliou;^ht to make
iinroundod clmrg(;s u^aiuHt writers who arc* no longer
livin^^'. It is plain that iill animalH with lungs
brcatlie. Jiut amongst th(^Sl^ the- animals that have; a
spongy, anaemic lung need respiration less than the
others. Consequently they can remain, owing to their
physical strength, a considerable time under water. All
oviparous animals have a spongy lung, as is the case in 3
froj^s.^ Attain, water- tortoises and land-tortoises can
remain a long time under water. In these animals the
lung has little heat, because it has little blood. Conse-
quently when it has been once inflated, it effects refrigera-
tion by its motion and enables the animal to continue a
long time under water without breathing. Even in these 4
cases, however, when the animal is forced to hold its
breath too long, it is suffocated. Tor none of these
animals can inhale water, as fishes do. All animals,
on the other hand, whose lung is full of blood, have
greater need of respiration, because of their greater
heat. As to the animals that have no lung at all, they
have no respiration at all.

^ In the frog the cavity of the lung is divided into a honeycomb of
chambers or alveoli. Each septum of the lung, being rich in elastic
tissue and equipped with a minute network of capillaries covered on
each side with epithelium, is freely exposed to the air, and owing to the
honeycomb structure of the lung the area of exposure to the air (and
consequent exposure of the blood) is great (cf. Foster, Physiology, 6th
ed, p. 557). Birds exhibit a reptilian rather than mammalian form of
lung (Owen, Anatom. of Vertebrates, vol. ii., p. 269).

CHAPTER 11.

Democritus of Abdera and certain other writers on the
subject of respiration have not spoken definitely about
the animals last named, but they appear to assert
that all animals breathe. Anaxagoras, however, and
Diogenes make the statement that all animals respire,
and they say that fishes and oysters are endowed with

2 a sort of respiration. Anaxagoras declares that when
471a fishes discharge water through their gills, they inhale

the air that is developed in the mouth (for a vacuum
does not exist), and so respire. Diogenes, on the other
hand, says that when fishes discharge water through
their gills, they inhale air by the action of the vacuum
formed in the mouth, out of the water which surrounds
the mouth, on the theory that water contains air.

3 These views, however, are untenable. For, in the first
place, they leave out of account half of the truth, because
their entire statement refers only to one aspect of the
case. For by respiration one understands partly in-
spiration and partly expiration, and they have nothing
to say in explanation of how the latter takes place

4 in lungless animals. And it is impossible for them

288

CUM', ir. AQUATIC ANIMALS 289

to fjivo any explanation. For when inspiration takes
place, expiration nnist also follow hy llic same
channel as that employed in inspiration, and these two
things must succeed each other in constant alternation.
The consequence is that exhalation must take place at
the same moment that water is being received into the
mouth, and in that case the one must impede the other
by meeting. Secondly, if they exhale by the mouth or 5
gills at the moment when they discharge water, the
consequence will be that inspiration and expiration will
bo simultaneous, and, according to the above assertion,
this is the moment in which animals inspire. But simul-
taneous inspiration and expiration is an impossibility.
Consequently, if it is true that respiration involves both
inspiration and expiration, and if it is further true that
aquatic animals are not capable of expiration, it is
clear that they are also incapable of respiration.

CHAPTER III.

Again, the assertion that they inhale air from the
mouth, or from the water through the mouth, is im-
possible. For aquatic animals have no windpipe, because
they have no lung, but the stomach is immediately
adjacent to the mouth, and consequently the stomach
would necessarily be the organ of inspiration. But if
this were true here, the stomach would have this power
in other animals also. As a matter of fact, it does not
have this power. Further, if aquatic animals were re-
moved from the water they would then clearly show this

2 capacity to respire ; but they do not show it. Further-
more, we observe in those animals that respire and
inhale air a certain movement in the organ of inhala-
tion. This is not observable in fishes. They appear to
move no organ about the stomach other than the gills,
whether they are in the water or are thrown gasping on

3 the dry shore. Again, when any respiring animal dies
471/^ from suffocation in the water, its breath, as it forcibly

leaves the body, is formed into bubbles, as one sees in

the case of tortoises or frogs, or other animals of this

sort, when they are forcibly drowned. With fishes,

290

< MM'. 111. RESPIRATION IN FISIIKS li'Jl

howevor, t-liis is not tho cafie, whatever nn'thod ono may
use, bociiu.sc they contain no inhaled nir. Acc(jr(iin«^ to 4
the exphmation of respiration above mentioned, it wouM
be poRsibh^ also lor men to n^spire when in water. For
if fish inhah^ air fiom water l)y means of their mouth,
why should not men and other animals do the same
thing ? Thi^y should inhale air from the mouth quite 5
as much as fishes. If the latter have this power, the
former should have it also. Ihit as this is not true in
the one case, it evidently does not hold good in the
other. Furthermore, if fishes respire, why is it that
we see them die in the air and gasp as if suffocated ? ^
It is not owing to lack of food. The explanation given 6
by Diogenes is foolish. He says that fishes, when in the
air, inhale too much air, and this is why they die, whereas
in the water they inhale a moderate amount. But this
should then be possible for land animals also. In point of
fact, no land animal is suffocated by excessive inhalation.
Further, if all animals respire, insects must evidently 7
respire also. Many of them, however, seem to live

^ Lewes {Aristotle, p. 176) says that the reason why fish die in the
air was, when he wrote the note (1864), still awaiting an explanation.
He was then not satisfied with the explanation of Flourens { Annates
des sciences Jiaturelles, 1830), which attributed suffocation to the
collapse of the gills in the air, and the consequent inadequate aeration
of blood, which no doubt is the chief cause, and Lewes' experiment in
artificially separating the leaflets of the gills would not seem to be
any adequate disproof. The number of respirations per minute in
water has been experimentally investigated by McKendrick {Journal
of Anatomy and Physiol, vol. xiv. 1879, p. 463) and found to varj' in
different fishes, ranging from 15 respirations (Rockling and Blue
Wrasse) to 120 (Minnow and Stickleback). It is, however, no doubt
true that rapid desiccation is a further cause of the dying of fish in
the air, and the protection against this by the coat of slime on eels
explains their living longer.

292 ARISTOTLE S PSYCHOLOGY de respir.

when they are divided, not only when divided into
two parts, but into several, as in the case of the centi-
pedes. How or by what organ is it possible for these
8 parts to breathe ? The chief cause of the error of
these writers was their ignorance of the internal organs,
and also the fact that they did not grasp the truth of
design in nature. For by asking to what end animals
are endowed with respiration, and by making a test of
their theory on the organs themselves, as, e.g., on the
gills and lungs, they would soon have discovered the
real explanation.

CHAPTER IV.

Democritus makes the statement, it is true, that respira-
tion produces certain effects in the respiring animal, viz.
it prevents the soul from being expelled from the body.
He by no means says, however, that nature in creating 472 a
this function did so with this end in view. For he is,
on the whole, like the other physicists ^ and makes no
application of any such causality. He maintains that the 2
soul and heat have one and the same nature, viz. they are
elemental spherical atoms. Consequently, when these are
compressed by the force of the surrounding air, inhalation
comes to their assistance. For in the air there is a large 3
number of the atoms which he calls mind and soul. In
the act of inhalation, then, and along with the entrance
of the air, these atoms also enter, and, by counteracting
the pressure, prevent the expulsion of the soul that
resides in the animal body. It is for this reason that 4
life and death depend upon inspiration and expiration.

^ We are almost entirely dependent on this account of Aristotle for
theories of respiration amongst the Presoci-atics. For the theories of
Galen and Hippocrates see the article of Steinheim, " Antike Lehre d.
Athmens " in Litt. Ann. d. gesamm. Heilkunde, vol. x. (1828), p. 257 ff.

293

294 Aristotle's psychology derespir.

For when the surrounding medium by its pressure gains
control and the outer air is no longer able to enter and
counteract this control, respiration in the animal becomes
impossible and death ensues. For by death one means
the departure of these psychical atoms from the body due

5 to expulsion by the surrounding medium. The reason,
however, why death necessarily comes at all to every
animal, and why it does not come at any chance period,
but in the course of nature only in old age, — a violent
death is contrary to nature, — he has not in the least
explained. And yet, because this phenomenon occurs
evidently at one period and not at another, it behoved
him to explain whether it is due to an external or to an

6 internal cause. Further, he has not a word to say
regarding the origin of respiration, whether its cause is
external or internal. And yet it is evidently not the
external mind that comes to the rescue here, but the
principle of respiration and of respiratory movement is
due to an internal cause, and we are not to suppose that
the force of the surrounding medium is any explanation.
It is also absurd to think that the surrounding medium
has at once the effect of extinguishing by compression,
and on its entrance the opposite effect. The foregoing,
in content and manner of statement, conforms closely to

7 the theory of Democritus. If one is to regard as true
what was said a while ago, viz. that not all animals
respire, then we must regard the Democritean explanation
of death as not universally applicable, but only to those
cases where animals breathe. But even to these cases it
does not well apply, as is evident from facts observed by

8 all of us. For in warm weather, when we are more than

ciiAi', IV. IIKAT AND KKSI'IKAIION 295

usually hoatcMJ, vvc have gniutt^r need of reHpirution and
we all breathe more rapidly. When, however, our
environnienl is eool and contracts and chills the hody,
we hold our l)reath. This is the very moment, however, 9
that the air from without should enter and prevent the
soul's expulsion. In point of fact it is the opposite that 472^
takes place. For when excessive heat is accumulated,
owing to its not being exhaled, that is the moment we
need respiration, and inhalation is necessary to this. The
truth is, men breathe rapidly when they are hot, because
respiration has a cooling effect, at the very moment
when ([according to the theory of Democritus]) they would
be, to use a proverb, 'adding fire to fire.'^

^ Because Democritus regards tlie soul-atoms as identical with the
heat-atoms.

CHAPTEK V.

The theory of circular push described in the Tiniaeus^
gives no explanation whatever of the way in which heat
is maintained in animals other than man, whether the
preservation of heat in the various animals is due to the
same or different causes. For if the phenomenon of re-
spiration is found in land animals alone, we must explain
why they alone breathe. If, however, it occurs in other
animals also, but by a different process, assuming that
they can all respire, we must find an explanation for the
2 difference in process. Furthermore, the whole manner
of explaining the phenomenon is fanciful. For Plato
says that by the issuance of hot air from the mouth,
the surrounding air is pushed forward and is transmitted
through the pores of the flesh, and rests at the point
from which the internal hot air issued. These elements
thus effect a complementary displacement, owing to the
fact that a vacuum is impossible. In the same way the

^ Timaeus, 79 A ff. Plato's explanation of the circular movement of
inspiration and expiration is expressly applied by him to the lowering
of animal heat, and not only in man but in all animals, as he says, *' in
the interior of every animal the hottest part is that which is around
the blood and veins " (Tmaett-s, loc. cit.).

296

niAP. V. J'LATO'S TirKORY 297

inhaled air in turn, vvlicn licalcd, in discliarj^cd and the
warm air witlnn, iHsuin^ out througli tlie mouth, continiioa
this * circuhir push.' And ho this j)rocc3HH, which is inspira-
tion and expiration, goes constantly on. The logical 3
consequence of the theory is that expiration precedes
inspiration, whereas the opposite is tlie fact, as the
following proves. The two things are correlated
phenomena. Now man's last act is expiration, conse-
quently inspiration must form the beginning. Further, 4
the end which these processes (I mean inspiration and
expiration) subserve in the animal body is not taken into
account at all by the philosophers who advocate this
theory. They treat them merely as unessential phe-
nomena. We see, however, that they are the master-
factors in life and death. For when a breathing animal
is unable to respire, at that moment death ensues.
Further, it is absurd to suppose that the issue of hot 5
air through the mouth and the entrance of air again
by the mouth should be observable by us, whereas
the entrance of the breath into the thorax and its
discharge should not be observable.^ It is also strange
that respiration should mean the introduction of
heat.^ Observation shows the contrary, for expired air is 6
hot, whereas inspired air is cool. And when the
atmosphere is warm animals pant in respiring and they
draw their breath frequently, because the entering air 473 a
does not adequately cool them.

^ That is through the pores into the thorax.

"Respiration to Plato means the introduction of heat only in so
far as it means the maintenance of heat and the supply of fuel
(Timaeus, 79 E).

CHAPTEE VI.

We must also reject the theory that the purpose of
respiration is nutrition, which presupposes the feeding
of internal heat by means of the breath. According
to this view, inspiration is similar to throwing fuel on a

2 fire, and expiration follows when the fire is fed. We
again urge the same objections to this theory as we did
to the theories enumerated above. The same process,
or something analogous to it, should be found in all

3 animals, for they all have vital heat. In the next place,
the advocates of this theory should explain how heat is
generated out of the breath. The whole view is fanciful.
According to our observation generation of heat is due
much rather to food. A further consequence of their
theory is that food is received and excrement discharged
at the same orifice,^ which is not seen in any other
instance.

^The reference may be to the Pythagoreans (cf. De, sensu 445a 16),
who asserted that certain animals are fed by the inspiration of smells.
But we have no details about their doctrine. Inasmuch, however, as
food here appears to be fuel for vital heat, the reference to Plato is
possible, who in the ' circular push ' theory would seem to admit food
and discharge waste by the same orifice.

298

CHAITKU VII.

Empedocles also has a theory of respiration, although
he does not explain the purpose of respiration, nor does
he say definitely whether all animals are endowed
with respiration or not. Tn treating of respiration
through the nostrils, he fancies he is dealing with
the main factor in this process. He is here mistaken, 2
for there is respiration through the windpipe, which
leads from the chest, as well as respiration through
the nostrils, and without a windpipe the nostrils
themselves could not respire at all. Animals may even
be deprived of respiration through the nostrils and suffer
no harm, but if the use of the windpipe is shut off they
die. In certain animals, indeed, respiration through the
nostrils is employed by nature for the secondary function 3
of smell. Although almost all animals are endowed with
the sense of smell, they do not all employ the same organ
for this purpose. On this subject, however, we have
spoken elsewhere more in detail.^ 4

Empedocles asserts that inspiration and expiration take 473 ^
place through particular veins, in which there is blood,

1 Cf. De an. 421a 7 AF. ; De sensu, 4446 16.
299

300 ARISTOTLE S PSYCHOLOGY de respir.

although they are not entirely filled with blood, and that
these veins are provided with channels that lead into the
outer air, channels which are too minute for the admission
of crass matter, but large enough for air. Now, the blood
is so constituted as to move up and down, and after its
downward motion the air streams in and inspiration takes
place ; on its upward motion expiration into the outer air
ensues — a process which resembles what we observe in
the Clepsydra : ^

5 Thus all things breathe and breathe out air again.

Long bloodless tubes the body's surface reach,
And at their close-packed vents are nostrils fixed
Pierced through ; and so a passage way is cut
For air, while yet the blood is hidden held.
When yielding blood along these channels ebbs.
Then bursts the surging air with tempest's wave
Within. But when the blood rebounds, the air
Is then expired again, as one may see
A child with smooth bronze water-clock at play.
Upon her comely hand she sets the tube.
And dips it in the yielding water's sheen.
Of which no drop slips in the vessel's form.
Upon the close-packed vents the air doth press
Within, until the maid her hand removes
And frees the urgent stream, which entrance makes,
Whose even flow drives back the yielding air.
So, too, when e'er the waters full free flow
Hath filled the deep bronze tube, and maiden Rand
The passage firm hath blocked, then doth the air,
The eager outer air, the vents make fast
And hold in its restraint the inner stream
Whose waters at the narrow gates complain,
^74 a Until the maiden lifts her hand. And now

Is true the converse of what was before :
The air flows in — the water's equal stream

^ Burnet {Early Greek Philos. p. 230) gives a valuable elucidation of
this passage.

ciiAi'. Ml. KMPKDOCIJCS 301

KlowH out, ThuH jiIho 'tJH with lliirnt ItNjo'l
Tliat cMmrHJMp; tlirmi^li our liinbrt now liiirrit'M }>Jick
To imuT (leptlm, and Htnii^^'litway air immmm in
Witli NUii^iii^ HW(>1I. A^ain the hlixnl rrturim
Kroiu its retreat ; then forthwith yiekls the air,
Exhaled once more, in nature'H even courHc.'

These are liis words on (he siil)ject of respiration. As 6
we have already said, animals that visibly respire do so by
means of the windpipe as well as by means of the mouth
and nostrils. Now, if Empedocles is speaking of respira-
tion in this sense, we must inquire how far his explanation
harmonizes with the facts. Apparently the facts con-
tradict his theory. For in inspiration the receptacle is 7
expanded like a brazier's bellows. Expansion, however,
is naturally explained by heat and by blood which takes
the place of heat ([but it is not explained by air in the
theory of Empedocles]). In expiration, on the other
hand, contraction and collapse take place, as in the
bellows, excepting that the cases are not quite parallel in
this respect, viz. the bellows do not admit and discharge
air by the same orifice, whereas in inspiration and expira-
tion the same orifice is used. If, however, he is here 8
referring merely to respiration through the nostrils, he is
quite wrong. For respiration is not a function which is
peculiar to the nostrils ; on the contrary, along the
passage near the uvula, at the extreme end of the roof of
the mouth, part of the air passes here through the
openings of the nostrils and part of it through the mouth,
and this applies equally to inspiration and expiration.

1 Vid. Fragments of Empedocles in Mullach's Fragmenta Philos.
Graec. (Paris, 1883), vol. i., pp. 10, 11.

CHAPTER VIII.

It was said above that life and the possession of soul are
accompanied by a certain degree of heat/ For even the
process of concoction, by which food is prepared for
animal life, cannot be accomplished without soul and

2 heat ; all this is effected by fire. Consequently, such a
fundamental process as this must be situated in the
primary region of the body and in the primary organ of
this region, and here it is that we must look for this

474^ elementary nutritive soul. This is the middle region
between the orifice for admittincj food and that for
discharging excrement. In bloodless animals the primary
organ has no name, in sanguineous animals it is the heart.

3 The food out of which animal members are generated is the
blood. The blood and blood-vessels must have the same
starting-point. For the one, as vessel and receptacle
exists for the other. The originating point for these
vessels in sanguineous animals is the heart. They do not

4 traverse the heart ; they all issue from it and are

^ Even plants, Aristotle correctly remarks (althougli he gives no
reason for the statement), exhibit vital heat {De part. an. 650a 6 ; De
ml. et mort. 470a 22).

302

oiiAP. Mil. ANIMAL IIKAT 303

attac'lied to it, an is cvidc^it from (lisscctionJ Now, Liu;
other fuiiclions ol" the soul caiiiKtl Ix; ix^foniH'd iu(l(;|)(jii-
(Icntly of tlu; niilrilivc priiiciph; (tin; rciisori lor whicli
has heon .stated in the treatiHC On ike in^ouiyf and the
nutritive principle in turn cannot subsist without natural
heat. For it is through natural h(;at that nature has
endowed the nutritive principle with warmth. Fire may
be destroyed, as we said before, in two ways : by extinc-
tion and by exhaustion. Extinction is effected by opposing,' 5
forces. Consequently even when the fire is massed it may
be extinguished by environing cold, and when scattered it
is more easily quenched. This extinction by external
force applies to animal heat as well as to inanimate fire.
For animals die when dismembered by instruments or
when congealed by excessive cold. Exhaustion, on the 6
other hand, follows from excessive heat. For if the sur-
rounding heat is great, and the internal supply of fuel is
not maintained, the fire ceases to burn, not from extinction
by cold, but from exhaustion. Consequently there must
be some cooling process, if survival is to be attained ; for
this comes to the rescue and prevents extinction.

^ There is no doubt that Aristotle practised dissection of animals,
although he probably never dissected the human body. His conclusions
in reference to the latter were drawn from the anatomy of other
animals, whence also the Asclepiads derived their knowledge, and his
errors are such as are due to this source of information and to his specu-
lative views as to anatomical structures {e.g. the bloodlessness of the
brain, its not extending to the back part of the skull, and its function
as a cooling apparatus). Further, the feelings of the Greeks regarding
the sacredness of the human body were much stronger than ours, and
neither Hippocrates nor Galen is supposed to have dissected man.
Cf. Hist. an. 494?) 22, 513a 12; Huxley, Xatiire, vol. xxi. ; Lewes,
Aristotle, p. 165.

2 Dean. 416a 10 ff., 434a 22.

CHAPTER IX.

Some animals are aquatic and others have their existence
on the dry land. In the case of the very small and
bloodless specimens of both classes, the cooling produced
by their surroundings, whether air or water, is adequate
to protect them against the above-mentioned extinction.
For being endowed with little heat they need little
protection. Animals of this kind are, consequently, in

2 the rule short-lived, for a slight change on one side or
475 a the other destroys the balance. The longer lived insects

(which, like all insects, are bloodless^) have a fissure just
below the middle part in order that cooling may be
effected through the membrane, which at this point is
very thin. For inasmuch as they have more heat they
have more need of cooling. Bees, for example, some of
which live as long as seven years, and the other insects

3 that hum, such as wasps, cockchafers, and locusts, belong to
this class. They produce this noise by their breath, as if

^The blood of insects is ordinarily a colourless liquid, sometimes
yellowish or greenish, and rarely red, and was not regarded by Aristotle
as blood. Cf. Owen, Compar. Anatom. and Physiol, of Invert. An.
p. 383.

304

(MiAi. IX. CONTROL OK riOMIMOKATUKK 305

by pantin*^'. Am thn iiiituriil bn^itliini^ within riscH and
falls, it produces friction ai^ainst the nicuibranc^ in the
middle ro<^ion. ]u)Y inscH'ts keep this ret^don in niotinn
just as animals tiiat breathe the outer air' maintain
motion by their lun<,^s or fishes by their ^dlls. This 4
motion is similar to what would take place if one should
sidfocate a respiring animal by holding its mouth ; for
then this swelling movement would be produced by the
lungs. In the latter case, however, such motion is
inadequate for cooling, although it is adequate in the 5
case of insects. By means of friction against a membrane
they produce a humming noise, as we said, in much the
same way as children make a noise through a perforated
reed after stretching a thin membrane in it.^ And it is in
this way, too, that the singing locusts produce their song.
They possess greater heat than other varieties, and have a
fissure in the middle region. In the songless locusts this
fissure is lacking. Sanguineous animals endowed with 6
lungs that contain little blood and are spongy, can live
a long time without respiration, because the lungs are
capable of great expansion, containing as they do
little blood or fluid. Consequently, their own peculiar

^ All insects breathe air, which enters chiefly through the thoracic
and first abdominal spiracles. In the case of insects living in the water
respiration is effected by branchiae or false gills, which are supposed to
absorb air from the water. Cf. Packard, The Study of Insects, p. 40 ;
Owen, Compar. Anatom. and Physiol, of the Invert. An., p. 368.

^Insects produce sounds by the vibration of their wings, by the
vibration and friction of the abdominal segments, and by rubbing
the head against the anterior wall of the thorax. The shrilling of the
male cricket (a sexual call) is produced by the friction of the fore wings
against the hind wings (cf. Packard, The Study of Insects, pp. 362, 563).
Aristotle further describes the methods by which insects produce
sounds in the Hist. Anim., 5356 4 ff.

U

306 Aristotle's psychology derespir.

motion is adequate for cooling through a considerable

7 period. Finally, however, it is unable to continue this,
and without respiration it suffocates, as we said before.
That form of exhaustion which consists in destruction
through lack of cooling is called suffocation, and animals
that die in this way are said to be suffocated. We have

8 already remarked that insects do not respire. One can
observe this plainly in the case of small insects, such as
flies and bees, for they can swim a long time in a liquid,

475(5 provided it is not too hot or too cold. And yet animals
which have less strength require more frequent respira-

9 tion. They are destroyed, however, and are suffocated,
as we say, when the belly is filled with water and the
heat of the middle region quenched. From this we can
understand how it is that such insects get up again after
being covered for some time with warm ashes. We also

10 observe that bloodless aquatic animals live in the air
longer than do sanguineous animals that take in sea-
water, as the fishes. For the former have little heat, and
consequently the air is adequate to cool them for a
considerable time, as is the case with Crustacea and

11 polyps. And yet it is finally inadequate for life, because
they possess little heat; for even fishes are often dug out
of the earth and found to be living, although motionless.
Animals that are endowed either with no lungs at all or
with lungs containing little blood, need the least frequent
respiration.

CHAPTER X.

In regard to bloodless animals we have said that some
of them owe their survival to the surrounding air,
others to the water. Tn the case of animals that have
blood and a heart, all those that are provided with
lungs take in air and effect cooling by means of inspira-
tion and expiration. Now, viviparous animals are 2
provided with lungs, not those, however, that bear their
living young outside of themselves (for the cartila-
ginous fishes are viviparous, but not within their own
bodies ^), and amongst oviparous animals those that
have wings are provided with lungs, as, e.g. birds, and
further, such animals as have scales, like the tortoises,
lizards, and snakes. Viviparous animals have a lung well 3
filled with blood, whereas most of the oviparous animals
have spongy lungs. Therefore, as we said before, the latter
need less frequent respiration. All of them, however, 4
do breathe, even those that live and maintain their
existence in the water, such as hydras, frogs, crocodiles,

^Mammalia are Aristotle's "internally viparons."' By "externally
Anviparous " he means the ovoviparous, which are without placental
attachment.

307

308 ARISTOTLE S PSYCHOLOGY de respir.

fresh-water tortoises, tortoises of the sea and land, and
seals. For all of these animals, and others similar to them,
bear their young on the land, and sleep either on land
or in the water with their mouths above the surface
476 « for respiration. Animals, on the other hand, that have

5 gills, are cooled by taking in water. To this class
belong the cartilaginous fishes and other apodous animals,
including all fishes. For their organs of locomotion are
after the analogy of wings ([rather than feet]). Amongst
animals that have feet, only one, so far as has been

6 observed, has gills, viz. the tadpole, as we call it. But
no case has ever been seen of the possession of lungs
and gills together. The reason is that the lungs are
designed for cooling by the admission of air (even the
name ttpcv/ulwu, ' lungs,' seems to have been derived from
their reception of Trveu/ma, ' air '), and gills are designed
for cooling by the admission of water. But only one
organ is used for one purpose, and one method of

7 cooling is adequate for each animal. And so, since
we know that nature makes nothing in vain, and since
one of these two organs would be useless, some animals
are provided with gills and others with lungs, but no
animal with both.^

^Ogle {op. cit. p. 125) points out that Aristotle cannot have been
acquainted with the Dipnoi or Amphipneusta, in both of which groups
gills and lungs co-exist.

CHAITEU XL

Since every animal needs food for its subsistence and
cooling for its persistence, nature employs for these
two purposes one organ.^ And as in some animals
the tongue is employed for the double purpose of tasting
and communicating thought, so in those which are
provided with lungs, the mouth serves for the masti-
cation of food as well as for inspiration and expiration
of air. In those, on the other hand, that have no 2
lungs and do not respire, the mouth serves for the
mastication of food, but gills are provided for cooling
where cooling is needed. In what way the functioning
of the aforesaid organs effects cooling, we shall explain 3
later. In order not to hinder the admission of food,
a similar method is employed by respiring animals and
by those that take in water. For in the former case
they avoid respiring and swallowing their food at the
same instant, otherwise they would choke by admitting
liquid or solid food into the lungs through the windpipe.

^ Cf. De part. an. 659a 22, 683a 19 ff. Elsewhere Aristotle refers
also to the nostrils as organs subserving respiration. De part. an.
6406 15, 659a 30. Cf. also above 473a 17 ff.

309

310 Aristotle's psychology derespir.

For the windpipe lies in front of the oesophagus, through
which food finds its way into the stomach. In the

4 sanguineous quadrupeds the windpipe is provided with
a sort of lid called the epiglottis. In birds and ovi-

476^ parous quadrupeds, on the contrary, there is no such
lid, but they attain the same end by contracting the
windpipe.^ When food is being swallowed, the ovipara
contract the windpipe, whereas the vivipara close the

5 epiglottis. And after the food has passed, in the one
case the windpipe is expanded, and in the other the
epiglottis is opened, and air is admitted for the purpose
of cooling. In regard to those animals that are pro-
vided with gills, they discharge the water through
these and then admit food through the mouth. They
have no windpipe, so that they can suffer no harm
by the wrong discharge of water into it, but only by

6 the entrance of water into the stomach. For this
reason, the discharge of water and the swallowing of
food is done rapidly, and their teeth are sharp, and
in almost all instances are serrated, for they cannot
chew their food.

^ In the mammalia food is prevented from passing into the windpipe
during deglutition by the epiglottis, which is possessed by no other
animals, while in other vertebrates this function is performed by the
closing of the larynx through muscular constriction {De part. an.
664/> 22). Cf. also HUt. an. 535a 29 ff. and De an. 4206 29, where the
functions of these organs in speech are treated.

CHAPTER XII.

Rf.garding the cetaceous aquatic animals, such as dolphins,
whales, and such others as have what is known as a spout-
organ, one might feel some doubt, yet even these conform
to our theory. For they are apodous, and although they
have lungs they take in sea-water. The ground for this
apparent exception is given in the foregoing explanation ;
for the end to which they take in water is not cooling. 2
This is produced in their case by means of respiration, for
they have lungs. Consequently, they sleep with their
mouths above the water's surface, and dolphins, it is
certain, snore. Again, when they are caught in nets, they
soon suffocate from lack of respiration. It is in order to
breathe, then, that we observe them lying on the sea's sur-
face. Since, however, they are forced to take their food in 3
the water, they must on swallowing discharge the water,
and for this reason they are all provided with a spout-organ.
When they have taken in water they discharge it through
this spout-organ, just as fishes do through their gills. A
proof of this fact is the position of the spout-organ. It 4
does not lead to any of the blood-filled organs, but is

situated in front of the brain and discharges the

311

312 Aristotle's psychology derespir.

water ^ here. For the same reason the molluscs and
crustaceans admit and discharge water. I mean the sea-
crayfish and crabs, as we call them. They make no use of it

5 for cooling, for they are endowed with only a small amount
of heat and are in every case bloodless, so that they are

477 « kept cool enough by the surrounding water. But it is
discharged on account of their food, viz. in order that the
water may not enter at the moment of swallowing. The

6 crustaceans, such as the sea-crayfish and crabs, discharge
the water through the plaited folds along their shaggy
covering ; the purple fish and polyps discharge it
through the hollow passage above the head. These

7 questions have been treated with greater detail in the
History of Animals!^ Concerning the phenomenon of the
admission and discharge of water, we have said that it is
due, in certain cases, to the need of cooling, and in others
to the fact that aquatic animals are obliged to swallow
their food in the water.

^Ogle [op. cit. p. 127) cites Cuvier {Regne animal, i. 285) as giving
the same explanation of the purpose of the blowhole, and says it is still
the popularly received, although erroneous, view. Its actual use is to
provide an additional safeguard (besides the epiglottis) against the
entrance of water into the air passages.

"^Hist. an. 525a30fiF.

CHAPTEK XIII.

We must next describe the method by which cooling is

eft'ected in respiring animals and in those provided with

gills. We have already said that animals which have

lungs respire. As to the reason why some animals have 2

this organ and why those that have it need respiration, it

is because the hii^her order of animals are endowed with

greater heat. At the same time it must be that they are

endowed with a higher order of soul. For such beings

are of a higher order than plants. Consequently, animals 3

whose lungs are more abundantly supplied with blood and

heat are of greater bodily dimensions than others ; and

the animal that is supplied with the purest and most

abundant blood, i.e. man, is the most erect of all animals,

and his upper structure points to the upper region of the

universe — true of him alone — because he has lungs

constituted as we have described. The essential character

both of man and of other animals must, therefore, be

ascribed as much to this as to any other organ. This, 4

then, is the purpose of the lungs. One must suppose that

the material conditions and moving cause have constructed

these animals in this way, as they have also operated to

313

314 ARISTOTLE'S PSYCHOLOGY de respir.

produce other animals with a ditferent constitution. For
some are composed chiefly of earth, like plants, others
chiefly of water, like aquatic animals. And amongst the
winged and terrestrial animals, the one class is composed
chiefly of air and the other of fire. And they severally
have their place in regions akin to their own natures.

CHAPTER XIV.

Empedocles ^ was wrong in saying that the aquatic
animals are warmest and contain most fire, and, being 477'^
defective in cold and fluid, they seek refuge from
constitutional excess of heat in a medium to which
their nature is opposed. For water is cooler than air.
It is, however, altogether unintelligible how animals born 2
on dry land can change their place of abode to water.
For they are, in almost all cases, apodous. And yet,
when speaking of their primary constitution, he asserts
they are born on the dry land and later leave this and
migrate to the water. Again, our observation shows 3
that they are not warmer than land animals ; for some
of them are absolutely bloodless, while others are almost

^ The writings are no longer extant from which Aristotle derived
these views of Empedocles, Lucretius, who was a follower of
Epicurus, and an admirer of Empedocles (cf. De rer. nat. i. 66, 716 ff. ),
gives expression to the same view {De rer. nat. v. 793), that land
animals cannot have migrated from water [scdais lacunis) to the land ;
on the contrary, all animals are land-born (a terra quoniam sunt cuncta
creata). The theory of Empedocles w^as allied to the ancient myth of
the Autochthons. Anaximander, on the contrary, taught the evolution
of animals from the moist element under the influence of the sun's
heat (Ritter and Preller, Philos. graec. p. 19a).

315

316 ARISTOTLE'S PSYCHOLOGY de respir.

SO, But what kind of animals we should call warm and
what kind cold, is a subject itself that requires investiga-
tion. Eegarding the explanation given by Empedocles,
his contention is, in a certain sense, correct, although

4 what he says is not entirely true. For it is true that
regions and seasons which exhibit characteristics opposed
to abnormal conditions in animals tend to preserve them,
and yet their normal nature is best preserved in a place of
abode similar to their own constitution. For the matter
out of which animals are severally constituted must not
be confounded with the varying states and conditions of

5 this matter. I mean, e.g. if a thing were formed of
wax or ice, its preservation would not be secured by
placing it in a hot environment. For, owing to the
opposed nature of its surroundings, it would be quickly
destroyed, for heat melts that which consists of the
contrary nature. Again, if a thing were composed of
salt or nitre, nature would not carry it and set it down
in a wet environment, for water dissolves substances of a

6 warm, dry constitution. If, therefore, the fluid and solid
constitute the matter out of which all bodies are formed,
it is reasonable to suppose that fluid and cold structures
will be found in a moist environment ; solid structures,
on the other hand, in a solid environment. Consequently,
trees do not grow in water, but in the earth ; although,

7 according to this same theory of Empedocles, they should
migrate to the water, because of their being predominantly
dry, or, to use his expression, " predominantly fiery."
This migration would be to water not because it is cold,
but because it is fluid. The natural constitution of
matter, therefore, conforms to the environment in which

niAi. XIV. IIKAT ANI> KNVIKONMKNT :iI7

it is Ibuiid — the inoi.st., (.(j. is Iniiiid in wiiLci', tin; vvunii 8
in the; air. Acciuirrd conditions, however, are butter 478a
rcguhited throuL^di an opposite onviroiiinent, excessive
heat throiij^h cold surroundings, and excessive cold
throuj^li warm surroundin^^s. For tlic environment
reduces the excess in these conditions and brink's them
to an equable mean. This reduction is to be sought in
an environment adapted to tlie particular constitution
of the thing and in the variations of ordinary climate.
For acquired conditions may be opposed to the place
of abode, but this is impossible in the case of the original
constitution.

Touching the theory of Empedocles that animals are 9
divided into aquatic and land animals on the basis of
differences in natural heat, and touching the explanation
of the phenomenon that the one class has lungs and the
other not, let the foregoing discussion suffice.

CHAPTER XV.

The reason why animals with lungs can take in air
and respire, especially such as have lungs well filled
with blood, is to be found in the fact that the lungs are
porous and filled with tubes. The lungs contain more
blood than any other organ in what we call the viscera.

2 Animals whose lungs are abundantly supplied with blood
need rapid refrigeration, because of the delicate balanc-
ing of the natural heat, and because the cooling process
must penetrate through the entire interior, owing to the
great supply of blood and heat. Air can easily meet
both these demands. For owing to its rarity, it rapidly
penetrates everywhere, and effects cooling.^ This is not

3 true of water. It is also plain from this why it is that
animals which have lungs well filled with blood breathe
best. It is due to the fact that the warmer the nature
the greater is the need of cooling, and at the same
time that the air fills the lungs, it passes readily to the
original source of animal heat in the heart.

1 Empedocles and Plato supposed that the air penetrated through the
pores of the skin, which in their theories became channels of venti-
lation.

.318

CHAPTEK XVI.

The way in which a passage is made between heart
and lungs must be studied through dissection, and in the
History of Animals} Animal nature, in general, needs
cooling, because of the vital fire in the heart. This is
accomplished by means of respiration, excepting in those
cases where animals are provided with a heart only but
no lungs. When they have a heart but no lungs, as is 2
the case in fishes, whose natural abode is water, cooling is
attained by water through the use of the gills. In regard
to the relative positions of heart and gills, one must study
them ocularly in dissection and their nicer philosophy in 478 <J
the History of Animals. To give a summary descrip-
tion, however, the case is as follows : One might suppose 3
that the position of the heart in land and aquatic
animals was different ; as a matter of fact, it is the
same in both. For the direction in which the animal's
head naturally inclines is the direction in which the
heart's apex is turned. But inasmuch as the heads of
land animals do not incline in the same direction as

^Cf. Hist. an. 496a 5 ff., 5116 24, where an historical account of
theories regarding the anatomy of the blood-ducts is given.

319

320 ARISTOTLE'S PSYCHOLOGY de respir.

those of aquatic animals, the heart's apex in the latter

4 case is turned towards the mouth. A sinewy vein-like
tube extends from the extremity of the heart ^ to a
central point, where all the gills are united. This is the
largest of all the tubes, but there are others on each side
of the heart which extend to the several extremities of
the gills, whereby cooling is produced and transmitted
to the heart, the water being constantly piped through

5 the gills. The rapid swelling and falling motion of
the thorax in inhaling and exhaling air serves the same
purpose in respiring animals that the movement of gills
does in fishes. Respiring animals suffocate in a small
quantity of air that remains unchanged ; for each medium
([water as well as air]) soon becomes hot, and contact

6 with the blood heats them. When, however, the blood
becomes hot, the process of cooling is impeded. Also
when respiring animals become unable to inflate their
lungs, or aquatic animals to move their gills, whether
owing to disease or to the weakness of old age, their
end must be at hand.

^ The aortic bulb, which Aristotle took to be the heart's apex.

CIIAPTEE XVII.

Birth and death are phenomena common to all animals,
although there are specific differences in their modes of
occurrence. Death is not everywhere the same, although
in its varied forms there is a common element. Death
ensues from violence or from the ordinary course of nature.
Death is violent when due to an external cause, natural
when due to internal processes. The latter conforms to
the original organic structure, and is not an adventitious
condition. In plants this process is called decay ; in 2
animals, senility. Death and decay attach to all organ-
isms alike that are complete, and to the incomplete also,
but in a different way. Under incomplete, I understand
such things as eggs, and seeds of plants which as yet
have not taken root. Death is caused in all things by
lack of heat ; in complete organisms by its failure in that
part where the vital principle is lodged. This principle 3
is lodged, as we said above, in the middle region, where
the upper and lower parts are conjoined. In plants it is
the point at which stem and root unite ; in sanguineous
animals, it is the heart ; in bloodless animals, in an organ 479 «

analogous to the heart. In some of the bloodless animals
X 321

322 Aristotle's psychology de respir.

we find many vital centres potentially, though not

4 actually. For this reason certain insects, when divided,
continue to live, and such sanguineous animals as are not
highly organized live a considerable time after the removal
of the heart, as is true of tortoises. Tortoises continue to
move their feet^ so long as their shell is not removed,
because their organization is of a lower order, resembling

5 in this respect the insects. The vital principle succumbs
in its possessor when the heat which is its accompaniment
is not reduced by cooling. For otherwise, as we have

6 often remarked, it is consumed by its own agency. When,
therefore, the lungs or gills respectively become hardened,
or dried up and earthy through lapse of time,^ it is
impossible for these organs to function, to dilate and
contract. And finally, when a further demand is made

7 upon them, the fire of life is extinguished. Consequently,
death quickly ensues in old age, even on the appearance
of trivial ailments. This is due to the fact that
there is little heat left in old age, most of it having
been exhaled in a long life, and if any extra strain
is put upon the lungs, life is speedily quenched.
For the fire within, being now but a tiny feeble

8 flame, is extinguished by a slight movement. That is
also the reason why death in old age is painless, for
death comes to the aged with no element of violence
in it, rather the dissolution of the soul occurs quite

9 without their feeling it. Diseases which make the lungs

^ Ogle {op. cit. p. 132) points out that this passage shows that
Aristotle occasionally vivisected animals, and cites the following
passages : Hist. an. 503b 23; De gen. an. 765a 26, 7746 31.

2 Or through the hardening (by drying) effects of fever or accretions
of matter on the lungs' surface.

oiiAr wii. KXTINCTION OK LIKK 323

hard, wli(;Mu;r hy tiiburcles or ile})OHit.s or by uxcessive
morbid heat, as in lovt'rs, produce an acceleration of tlic;
breathing, because th(^ bmgs are incapable of full expansion
and contraction. And linMlly, when motion is no longer
possible, men exhale their breath and die.

CHAPTER XVIII.

Birth, then, is the original suffusion of the nutritive soul
with heat, and life is the maintenance of this heat.
Youth is commensurate with the growth of the primary
organ of cooling, old age with the wasting of the organ,
and the prime of life with the middle period between the

2 two. Death and violent destruction mean respectively
the exhaustion ^ and extinction of the vital heat (for it is

479 b destroyed from both causes) ; exhaustion is given in the
nature of the thing itself, and is caused by lapse of time

3 and by the completion of a normal term of life. In
plants this is called decay ; in animals, death. Death in
old age is due to the exhaustion of the organism that
comes from senile inability to effect cooling. AVe have
now explained the meaning of birth, life, and death, and
have treated the causes of these phenomena in animals.

^ Extinction (o-/3^crts) is violent or artificial ; exhaustion (/idpaj/o-ts) is
natural or due to the inherent nature of the thing itself. Cf. Dt vit. et
mort. 4G96 23 ; De resp. 4746 14.

324

CHAPTER XIX.

Fkom these considerations one may clearly see why it is
that respiring animals are suffocated in water, while
fishes are suffocated in the air.^ For in one case cooling
is effected by the medium of water ; in the other by that
of air, and both of them are deprived of this by the
change in their place of abode. We have further to 2
explain the movement ^ in gills and lungs respectively, —
exhalation and inhalation in the one case, and the
admission and discharge of water in the other. We
have also to explain the structure of the organ of
respiration in what follows.^

1 Vid. note 1, p. 291.

"i.e. by the movements of these organs the cooling medium (air or
water) is admitted to the organism and the temperature regulated.

"The explanation follows in Chapter xxi. Ogle (p. 132) considers
Chapter xx. an interpolation.

325

CHAPTER XX.

There are three phenomena regarding the heart, which
might be supposed to have the same nature, but are
different, viz. palpitation, pulsation, and respiration.

2 Now, palpitation is a compression of heat in the heart,
owing to cooling in other parts of the body produced
by excretion or waste, such as we see in the disease
called palpitation of the heart, as well as in other
diseases, and in fear also. In fear the upper regions
of the body are cold, and their heat is discharged
and collected in the heart, where palpitation is caused,
and the heat being thus compressed into a small space,
it sometimes happens that animals are suffocated and

3 die from fear and its morbid conditions. The pheno-
menon of pulsation, however, that occurs in the heart,
and which, as we see, is a constant process, is similar
to the throbbing in an abscess. In the latter the move-
ment is painful owing to abnormal change in the blood.
This process continues to a point where the blood is

4 concocted and converted into pus. The condition is

analogous to boiling. For boiling takes place when

water is evaporated by heat, and it bubbles up owing to

326

cMAf. XX. MOVKMMNTH OF TIIK HICAItr 327

its incroast^ iii voluino. Tho dovelopmcnt of abscesses
is iirrosti'd when tlui pus is not i)Vii])oriit(Ml and the licpiid
becuiiies very thick; tlu; process in hoiliii;^ is arrested 4^0 '^
when the conlining vessel is overllowed. The supj)ly of 5
moisture diMivinl from I'ood and its expansion through
heat produces ])ulsation in the heart, — the expansion
extending to the heart's outer covering. And this is a
constant process, for tlie flow of Ihiid to the lieart, out of
which the blood is generated, is constant. It is in the
heart that blood is first formed. One can observe this 6
plaiidy in the growtli of an embryo.^ For before the
veins are distinguishable the heart is seen to contain
blood. Pulsation, for this reason, is more marked in
youth than in old age. For the process of evaporation
is stronger in youth. The blood vessels all pulsate, and 7
they do so simultaneously, for they are all connected
with the heart and originate in it. The heart, however,
is in constant motion. So, too, the blood vessels are in
constant motion, and simultaneously with each other, as
long as the heart moves. Palpitation, then, is a re-
action in the heart due to the compression of heat by
the cooling of other parts of the body ; pulsation is the
evaporation of the moist element as it becomes heated.

^Cf. note 1, p. 276.

CHAPTER XXI.

Respiration is due to the increase of the heated element, in
which the nutritive principle is lodged. As all other bodily
elements need maintenance, so does this element of vital
heat, and even in a greater degree than the others, for it is
the source of maintenance for the other elements. When
it is increased, it necessarily expands the organ in which it

2 is found. One must conceive the structure of this organ to
resemble a brazier's bellows. For neither lungs nor heart
differ very much from a form such as is illustrated by a
bellows. Both are double.^ The nutritive principle must
be situated in the centre of the vital power.^ The lungs
then increase and expand, and, by expanding, the part
in which they are lodged must also expand. We see this

3 when we respire. For the thorax is then expanded,
because the inherent principle in this part is expanded.
Owing to this expansion, as one sees in the bellows,
cold air must be introduced from without and, by

480;^ its cooling effect, the excess of internal heat is lowered.

^ There was a double as well as single form of bellows in use in ancient
Greece.

^ Ogle adopts a conjecture of Mr. Poste — iJ/vKTiKrjs for <pvffiKrji.

328

CHAP. \xi. CONDITIONS OF \AVK 329

lint just as tho orgjui vvjik expanded owing to the increase 4
of heat, so now it necessarily contracts when tlie heat is
diminished, and l>y contracting, tlie air wliich was inhaled
is again discharged — air that was cold when admitted, l)ut
warm when discharged owing to contact with the heat
inherent in the organ, especially in the case of animals
whoso lungs are well-lilled with blood. Tlie air enters
through a mass of pipes, canals as it were, with which the
lungs are provided, and blood vessels extend alongside each
of these pipes, so that the entire lung appears to be filled
with blood. The admission of air is termed inspiration, 5
and its discharge, expiration. The process of respiration
is continuous, so long as life and this organic motion
continue. Life, therefore, is given in the processes of
inspiration and expiration. The movement of the gills
in fishes is produced in the same way. For by the 6
expansion of the blood's heat in its course through the
members, the gills are lifted and water passes through.
When, on the other hand, the heat retreats to the heart
through the channels and cooling is effected, the gills are
lowered and the water passes out. The expansion of the
heart's heat is constant and its re-admission when cooled
is constant. And so in animals provided with lungs, life
and death are ultimately conditioned by respiration, and
in fishes by the admission of water.

This, then, is a statement of our views of life and death 7
and of almost all the questions germane to them. It is
the province not only of the physician, but also of the
natural philosopher, up to a certain point,-^ to discuss
questions of health and disease. We must not, how^ever,

^ Reading fi^pi tov for fx^xP^ '^^^-

330 Aristotle's psychology de respir.

forget how these two classes of men differ and how they
regard a subject from different points of view, although
experience shows that both professions are, to a certain
extent at least, conterminous. For the better educated
and more painstaking physicians are conversant with the
laws of nature and deem it correct to derive their principles
of practice from this source, while the best trained
philosophers ^ of nature almost always conclude with a
discussion of the principles of medicine.

iCf. Deaensu, 436a 19 fif.

lUliLIOGKAPHV

*,* Tlio f»iU«)wii\^' works havo bocn foiiixl viilimMo in tin; |>n ii.inition of tho

t)ii'sont voluino. I'lirllu-r litli-s iiro loforrod (<> in lliu nntcH. Onl^' mu<1i \v<»rkH aro
nrludoil as havo ininiodiato ruforcnfo ti> tlio rsycholdKy. For a nioro varied and
coniploto bibliotfraphy soo M. Schwab, BibliographU d'Aiistole (FariM, J.iijrurio H.
Woltor, ISSUi).

Alexaiidri Aphrodisiensis praeter commentaria Bcripta minora dc
aniina cum Mantissa. Ed. Bruns. Buroliiii, 1887.

Aristotle. De anima. Recen. A. Torstrik. Berolini, 1862.

— De anima. Becog. et comment, illust. Trendelenburg. Ed. altera.

Berolini, 1877.

— De anima. Becog. W. Biehl. Lipsiac, 1884.

— De anima lib. B secundum recensionem vaticanam. Ed. H. Rabe.

Berolini, 1801.

— Parva naturalia. Becog. W. Biehl. Lipsiae, 1898.

— Opera omnia, ex recensione Bekkeri. 5 vol. Berolini, 1831-1870.

— Opera omnia, ex recensione Bekkeri. 11 vol. Oxonii, 1837.

— Opera omnia graece et latine. 5 vol. Parisiis, Didot, 1848-18(50.

Bartholemy-St.-Hilaire, Psychologic (Traits de I'ame), trad, par
Barth61emy-St.-Hilaire. Paris, 1846.

— Psychologic (Opuscules), trad, par Barth^lemy-St.-Hilaire. Paris,

1847.
Baumker, C. Des Aristoteles Lehre von den aussern und innern
Sinnesvermogen. Leipzig, 1877, pp. 91.

Beare, J. I. Aristotle's Parva Naturalia. Herraatheua, vol. ix. (1894),
pp. 1-29.

— Notes on Aristotle's Parva Naturalia. Hermathena, vol. x. (1899),

pp. 455-473.

Beck, H. Aristoteles de sensuum actione. Berolini, 1860, pp. 55.

Bender, W. Schrift iiber die Seele. Ubers. von Bender. Stuttgart,
1872.

— Die kleinen naturwisseuschaftlichen Schriften (Parva Naturalia).

Ubers. von Bender. Stuttgart, 1873.

Biehl, W. Uber die aristotelische Definition der Seele, Leipzig,
1863. Verhandlungen der 21sten. Versammlung deutscher
Philologen und Schulmiinner zu Augsburg, pp. 94-102,

— Uber den Begriff j'oOs bei Aristoteles. Linz, 1864, pp. 20.

Biese, R. Die Erkenntuisslehre des Aristoteles und Kant's in
Vergleichung ihrer Grundprincipien. Berlin, 1877, pp. 74.

Bobba, R. La dottrina dell' intelletto in Aristotile, Torino, 1896,
pp. 479.

331

332 Aristotle's psychology

Bonitz, H. Aristotelische Studien. Wien, LS63-67.

— Uber das erste Bnch der aristotel. Schrift iiber die Seele.

Monatsber. der Konigl. Preuss. Akad. d. Wiss., 1873, pp. 481 fF.

Breutano, F. Von der mannigfachen Bedeutung des Seienden nach
Aristoteles. Freiburg i/B., 1862, pp. 220.

— Die Psychologic des Aristoteles, insbesondere seine Lehre vom uovi

Troi7)TLK6s. Mainz, 1867, pp. 252.

— OfiFener Brief an Herrn Professor Dr. Eduard Zeller, Leipzig,

1883, pp. 36.

Bullinger, A. Des Aristoteles Erhabenheit liber alien Dualismus.
Miinchen, 1878, pp. 94.

— Aristoteles' Nus-Lehre. Dillingen, 1882, pp. 73.

Chaignet, A. E. Essai sur la psychologic d'Aristote. Paris, 1883.

Collier, C. Treatise on the Principle of Life. Translated by C.
Collier. Cambridge, 1855.

Deinhardt, J. H. Der Begriff der Seele mit Riicksicht auf Aristoteles.
Hamburg, 1840.

Eberhard, E. Die aristotelische Definition der Seele und ihr Werth
fiir die Gegenwart. Berlin, 1868, pp. 62.

Essen, E. Die I. und II. Biicher der aristotelischen Schrift iiber die
Seele. Jena, 1892, 1894.

Freudenthal, J. Uber den Begriff des Wortes (pavraaia bei
Aristoteles. Gottingen, 1863, pp. 59.

— Uber das Buch Trepl tQv kolvCov adjinaTos Kal ^I'xv^ ^pyiou. Rheinisches

Museum, vol. xxiv. (1869), pp. 81-93, 392-419.

— Zu Aristoteles de memoria, 452. Archiv fiir Geschichte der Philos. ,

1888, pp. 5-13.

Frohschammer, J. Uber die Principien der aristotelischen Philo-
sophic und die Bedeutung der Phantasie in derselben. Miinchen,
1881, pp. 143.

Granger, F. Aristotle's Theory of Reason. Classical Review, Vol.
vi. (July, 1892).

— Aristotle's Theory of Reason. Mind, Vol. xviii. (1893), pp. 307-318.
Grote, G. Aristotle. London, 1872, 2 vols.

Giithling, K. E. Die Lehre Aristoteles von den Seelentheilen.

Liegnitz, 1882, pp. 11.
Hammond, W. A. Aristotle's Doctrine of (pavracla. Proceedings of

the Amer. Philol. Assoc, Vol. xxxii.

— Aristotle's Doctrine of the Central or Common Sense. Proceed-

ings of the Amer. Philol. Assoc, for July, 1897, pp. ix. ff.

— Aristotle's Doctrine of ^vxn as biological principle. Psychol.

Rev., Vol. V. (1898), pp. 159 f.

— Theory of the Will in Aristotle's Ethics. Psychol. Review, Vol.

vi. (1899), pp. 169 f.
Hartenstcin, G. De psychologiae vulgaris origine ab Aristotele
repetendo. Lipsiae, 1846, pp. 19.

Heman, K. Zur Geschichte der Lehre von der Freiheit des mensch-
lichen Willens. Erstes Heft. Leipzig, 1887, pp. 194.

mi'.MOCHAPHY :VMi

Hopncr, 10. AMwukUuii^' vom jIl-im (icdiK-'litninH iiml tli r WiidiT.
oriniuirung. ri)iirHi!t/.t voii K. Il»'[)iu!r, IM'JI.

— AhhniuUun^ vom Schlafo iiinl vom VViichoii. Auh doiu (iriechiMohon

iihcra. von K. ll(|)ii«>r. HreHlau, IH*J4.

licrtlinu, (i. i'*. von. Miitcrio iiixl l<'(>i-iii iiiid dio I)(liidti<in di^r
ISoolo boi AriHtotiilt'H. lioiiii, 1871, iii>. 17H.

iFounnis Vhiloponi in Ai'istolcliB Do uniiii:i liltios i-oiiuiiciituriii. lOd.
llayduck. I'.cKdiiii, 181)7.

KiuniH), F. F. Die lOrkcnntnissthcorio dca Aristotck-a. Lcipzit,',
1870, pp. ',V.i4.

Kii'chnwinn, (J. II. von. Drei Biicher voii der Socio. UhorH. uiid
erkliirt von G. H. von Kiichmnnn. Ikrlin, 1871.

Kronz, F. A. Droi liUchor von dor Seole. Ubora. von Krouz.
Stuttgart, 1817.

— Kloine Abhaiidlungon iibcr die Secle. Ubers. von Kreuz.

Stuttgart, 1817.
Lewes, G. H. Aristotle. A chapter from the History of Science.
London, 1864, pp. 404.

Meyer, J. B. Die Thierkunde des Aristoteles. Ein Beitrag zur
Gcschii'hto dor Zoologie, Physiologic, und alten Philosophic.
Berlin, 1855, pp. 520,

Michaelis, K. G. Zu Aristoteles de anima iii. 3. Neu-Strelitz, 1882,
pp. 20.

Muller, Johannes. Aristoteles iiber den Trauni. Eine physiolo-
gische Urkunde. Coblentz, 1826.

— Uber die phautastischen Gesichtserscheinungen. Coblentz, 1826.

Neuhauser, J. Aristoteles Lehre von dem sinnlichen Erkenntniss-

vermogen und seiuen Organcn. Leipzig, 1878, pp. 132.
Ogle, W. On Youth and Old Age, Life and Death, and Respiration.

Trans, with introduction and notes by W. Ogle. London, 1897,

pp. 135.
Partzsch, T. Aristoteles Lehre von der Seele nach ihren Grundziigen.

Dresden, 1873, pp. 35.

Philibert, H. Du principe de la vie suivant Aristote. Paris, 1865.
Philippson, L. 'TXt] dvOpcoirii^r]. Partes duae. Berolini, 1831, pp. 252.

Poppelreuter, H. Zur Psychologic des Aristoteles, Theophrast,
und Strato. Leipzig, 1892, pp. 52.

Pouchet, G. La biologic aristotelique. Paris, 1885.

Eitter, B. Die Grundprincipien der aristotelischen Seelenlehre.

Jena, 1880, pp. 32.
Rodier, G. Aristote. Traite de I'ame. Traduit et anuote par G.

Rodier. 2 vols. Paris, 1900.
Schell, J. H. Die Einheit des Seelenleben aus den Principien der

aristotelischeu Philosophic cntwickelt. Freiburg i/B., 1873,

pp. 209.
Schiebold, F. 0. De imaginatione disquisitio. Lipsiae, 1882, pp. 70.
Schlottmann, K. Das Vergangliche und Unverganglichc in der

menschlichen Seele nach Aristoteles. Halle, 1873, pp. 57.

334 ARISTOTLE S PSYCHOLOGY

Schneider, L. Die Unsterblichkeitslehre des Aristoteles. Passau,

1867, pp. 141.
Siebeck, H. Die Lehre des Aristoteles von detn Leben und der

Beseelungd. Universums. Zeitsch. fiirPhilos. undphilos. Kritik.

Bd. 60(1872), pp. 1-39.

— Geschichte dor Psychologie. Theil I. Abth. i., ii. Die Psycho-

logie bis Thomas von Aquino. Gotha, 1880, 1884, pp. 284, 531.

— Untersuchungen zur Philos. der Griechen. Zweite Aufl. Frei-

burg i/B., 1888, pp.279.

— Aristoteles. Stuttgart, 1899, pp. 142.

Simplicii in libros Aristotelis de anima commentaria ed. Hayduck.

Berolini, 1882.
Sommerfeld. Die Psychologie von Aristoteles und Beneke, Gross-

Glogau, 1879, pp. 12.
Sophoniae in libros Aristotelis de anima paraphrasis ed. Hayduck.

Berolini, 1883.
Sperling, K. Aristoteles Ansicht von der psychologischen Bedeu-

tung der Zeit. Marburg, 1888, pp. 73.

Susemihl, F. Zu Aristoteles Psychologie. Philologus, Bd. 46 (1886),

pp. 86.
Teichmiiller, G. Neue Studien zur Geschichte der Begriffe. Heft III.

Die praktische Verunft bei Aristoteles. Gotha, 1879, pp. 453.

Themistii in libros Aristotelis de anima paraphrasis ed. Heinze.
Berolini, 1899.

Voigt, M, W. tjber die menschliche Seele. Ubersetzt und mit
Anmerkungen begleitet von M. W. Voigt. Leipzig, 1803.

Volkmann, W. F. Die Grundziige der aristotelischen Psychologie.
Aus den Quellen dargestellt. Prag, 1859.

Waddington, Ch. De la Psychologie d'Aristote. Paris, 1848. pp.

384.
Wallace, E. Aristotle's Psychology. In Greek and English, with

introduction and notes by Edwin Wallace. Cambridge, 1882^

pp. cxxviii, 327.

Walter, J. Die Lehre von der praktischen Verunft in der griech.
Philos. Jena, 1874, pp. 573.

Weisse, C. H. Von der Seele und von der Welt. Ubersetzt und
mit Anmerkungen begleitet von C. H. Weisse. Leipzig, 1829.

Wilson, J. Cook. Conjectural Emendations, .Journal of Philol.
Vol. xi. (1882), pp. 119-124.

Wolff, W. Von dem Begriffe des Aristoteles iiber die Seele und
dessen Anwendung auf die heutige Psychologie. Bayreuth, 1848,
pp. 16.

Zeller, E. Uber die Lehre des Aristoteles von der Ewigkeit des
Geistes. Abhandl. der Akad. d. Wiss., Bd. xlix., pp. 1033 ff.
Berlin, 1882.

— Aristotle and the Earlier Peripatetics, translated by Costelloe and

Muirhead. London, 1897, 2 vols.
Ziaja, J. De sensu. Cap. 1 bis 439& 18. Ubersetzt und mit

Anmerkungen versehen von J. Ziaja. Breslau, 1887, pp. 16.

INDEX.

Abstraction, 125.
Actuality, ^'^, G'^ f.
Atrections, nature of, 29.
After-image, 23C.
Air, as medium, 76 fF.
Alcinaeon, 10.

Anaxagoras, on respiration, 28S ;

on soul, 12-17.
Anger, detinition of, 8.

Animals, classification of, 171
distinguished from plants, 272
longevity of, 263, 266, 304
ovoviviparous, 307.

Animate, 10.

Animism, 49.

Appetite, 133.

Association of ideas, 205.

Atomic theory, 2nd. under Demo-
critus.

Birth, 324.

Blood, circulation, 227 ; effect on
dreams, 242; movements in,
243.

Body, dissection of, 303 ; divisions
of, 273 ; elements in, 60 ; poten-
tiality, 46 ; relation to soul, 40-
53.

Brain, organ of cooling, 80, 228 ;
size in man, 176.

Categories, 4.

Cause, meanings of, 58, 220, 248.

Chance, 250.

Cognition, 35.

Colour, explanation of, 71, 158,

160; number of, 168; primary

colours, 87.

Common sense, in consciousness,
99 ; in judgment, 103 ; in sense-
perception, 97 ; in unification,
192.

Common sensible?, 97 ff., 232.
Conception, 106.

Conduct, reason and desire in,
131.

Consciousness, in sleep, 245-?53.
Continuity, 120, 181.
Critias, 16.

Death, 261.

Deduction, 6.

Definition, 6, 8, 23, 48.

Deliberation, 136.

Democritus, atomic theory, 32 ;
dreams, 252 ; theory of soul, 11,
15, 21, 30, 32, 37 ; primary and
secondary qualities, 101 ; respira-
tion, 288-294; touch, 169;
vision, 153.

Desire, 54, 123, 133, 137.
Diaphanous, 71, 73, 158 f., 171.
Diogenes of Apollonia, 15, 288,
291.

Disjunction, 119.
Divisibility, 39 ff., 120.

335

336

ARISTOTLE S PSYCHOLOGY

Dreams, atribilious, 254 ; memory
of, 246 ; observation of, 245 ;
origin of, 231, 251 ; prophetic,
248, 250.

Echo, 76.

Emotions, 8.

Empedocles, on evolution, 315 ;
growth, 59 ; harmony, 27 ;
knowledge, 35 ; light, 72 ;
movement of blood, 300; respira-
tion, 299 f. ; soul, 13, 27, 34 ;
taste, 164 ; vision, 151 f.

Entelechy, 42, 44.
Environment, 317.
Epiglottis, 310.
Error, 119.
Eye, 153-155.

Faculties, vid. under Soul ; classi-
fication of, 54, 57, 58.

Feelings, physically expressed
ideas, 6-8.

Flavour, vid. under Taste.
Democritus on, 170 ; haptic
quality, 55 ; primary flavours,
87; theories of, 164-167,

Form, 42, 53, 220.

Frogs, artificial, 244.

Good and bad, 124.

Hard flesh, 41.

Harmony, relation to soul, 26 fi". ,
102 ; Xenocrates on, 30.

Hearing, importance of, 144, 148,
149 ; nature of, 76 ff. ; organ of,
78.

Heart, centre of life, 275 ; connec-
tion with lungs, 318 ; first organ
to develop, 277 ; organ of
nutrition, 302; organ of sensa-
tion, 279 ; palpitation, 326 ;
structure of, 229.

Heat, animal, 280, 303, 322 ; con-
trolled by respiration, 295.

Heraclitus, 15.

Hippo, 15.

Ideas, association of, 205.

Illusion, example of, 240 ; in
dreams, 239.

Imagination, control of, 106 ; de-
finition of, 107, 110 ; distin-
guished from memory, 201 ; in
dreams, 234, 242, 245 ; organ of
240 ; productive and reproduc-
tive, 56 ; relation to thought,
109, 123, 127, 198 ; relation to
desire, 135 ; residual sensation,
244.

Immortality, 51, 58.

Insects, live after division, 274 ;
respiration of, 305.

Ionian physiologers, 17.

Judgment, function of common
sense, 103 ; function of thought ;
128 ; inhibition of in sleep, 243.

Knowledge, actual and potential,
122 ; kinds of, 1, 48 ; two
powers of knowing, 231.

Leucippus, 11.

Life, centralisation of, 276 ; con-
nection with vital heat, 280,
322 ; destruction of, 258, 281,
324 ; duration of, 256, 262, 267,
304 ; in insects, 268 ; meanings
of, 49 ; relation to respiration,
293, 329 ; seat of, 271 ; unity
of, 275.

Light, cause of vision, 152, 185 ;
diaphanous, 71; motion, 184;
nature of, 157.

Locomotion, 129.

Longevity, 256, 265.

Lungs, coexist with gills, 308 ;
function of, 80, 308 ; organ of
refrigeration, 318 ; organ of
respiration, 306 ; spongy, 307 ;
structure of, 328.

Magnitude, relation to sensation,
162, 181.

Man, most intelligent animal, 82.

Matter, 42.

Medicine, connection with philo-
sophy of nature, 147, 330.

INDKX

XM

Modiuin, condition of HoiiHo-per-
(•option, 7.'» II., IH'{ ; for pmoiM)-
tion at tliHtancti, lU); of Hounil,
75 : of toiu;li. SO ir.

Memory, dofinitiun of, lO'i ; im-
print of Ho.-vl-iinK. li'5); in youth
and old nv'(\ \\)\) : pnu'CHHoa of,
*J()1) : ()l>jiH;t of, I'.Mi; relation to
imai^ination. III, *J(>I ; relation
to reason, 'Jl> ; n-lation to timo,
197, '-'10 ; Hi'at of, *J()2 ; why
strengthened by exercise, *2(VJ.

Method, kinds of, 1^.

Monad, soul a, 30.

Motion, Domocritus on, '21 ; de-
fined, 19, 87, *22.'^ ; in conduct,
13:^, 137 ; in sleep, 242; Tlatonio
tlieory of, 19 ; relation to light,
72 ; relation to sensation, G5,
238 ; relation to soul, 18, 23, 28,
30, 37.

Myths, Pythagorean, 24.

Nature, purpose in, 59, 221.
Nominalism, 4.
Number-theory, 32.

Nutrition, faculty of, 57, 62 f.,
138 ; orsjan of, 273 ; relation to
smell, 174; seat of, 271, 276;
shared by plants, 50 ; sweet in,
168.

Old age, 270, 324.

Opinion, not possessed by lower
animals, 136 ; relation to imagi-
nation, 111.

Orphic verses, 37.

Palpitation, 326 f.

Parva Naturalia, 145.

Perception, limits of, 193 ; per-
ceptibility and magnitude, 182 ;
unity in, 192.

Phantasy, vid. under Imagination.

Philaegides, 254.

Philosophy of nature, relation of

to medicine, 147, 330.
PlantSjdiflferentiatedfromanimals,

272 ; duration of life in, 267 ;

heat in, 2H4, 302; Moul in, 41,
50 ; without HiMiHution, 94.

Plato, *<.irculjir piiMli,' '"Mi; /)in
rourst'Hon I'hi/oso/thi/, I'.i ; fucul-
tiuH of Houl, 51 ; on motion, 14 ;
nature of the soul, 13, 21, 33 ;
Tinuuns, 51, 151 ; on vinion,
151.

Pleasure and pain, 51, 122.

Potentiality, meatiitig of, 4, 44,
(i4-68, 87 ; relation to know-
ledge, 66, IOC.

Pre- Aristotelian psychology, 11 ff. ,

26 ir.

Predication, 121.

Principle, meaning of, 2.

Proof, demonstration, 23.

Psychology, pre- Aristotelian, 10 AT.

Pulsation, 326.

Pythagoreans, myths, 24; nature
of soul, 11, 17, 24, 26, 53;
respiration, 298.

Qualities, primary and secondary,
101.

Realism, 4.

Reason, active, 47, 112-118;
Anaxagoras on, 12 ; divine nature
of, 29 ; epitactic, 130, 132 ; in-
destructible, 29; practical, 124,
125, 135; relation to imagina-
tion, 110 ; separability from
body, 24 ; thinks abstractions,
125 ; thinks external world, 181 ;
time necessary to, 197; unify-
ing principle, 120.

Recollection, definition of, 195 ;
deliberation in, 211; diflFerent
from memory, 204; how pro-
duced, 206; in youth and old
age, 212 ; movement from within,
29; not shared by lower ani-
mals, 211.

Reflex-movement, 275.
Refrigeration, organs of, 80; pur-
pose of, 284.

Respiration, in aquatic animals,
289, 291, 311 ; functions of, 297 ;
in insects, 305; organ of, 301;

338

ARISTOTLE S PSYCHOLOGY

in old age, 320; Plato's theory
of, 296 ; purpose of, 286 ; in
whales, 311.

Sapid, defined, 85, 86.

Sensation, activity of, 237; com-
mon sense, 70, 97, 99 ; co-
ordination in, 189; definition
of, 9.3, 112; duration of, 190;
in dreams, 233 ; fusion, 187 ;
medium, 182; mean, 92; move-
ment from without, 29 ; organs
of, 96 ; necessary to animal
life, 138; persistence of, 2.39;
purpose of, 147 ; qualitative
change, 236; relation to heart,
277; relation to thought, 106;
seat of, 279; simultaneity in,
186; in sleep, 241, 249. Vid.
under the particular senses.

Sense-object, 69, 102.

Sense-perception, 64fif., 101.

Sense-quality, 69, 181.

Senses, correlated with physical
elements, 150; five, 95 ff. ; higher
and lower, 140, 148.

Sensibility, relation to magnitude,
180, 193.

Sensibles, common, 97 ff., 232.

Sight, vid. under Vision; impor-
tance of, for higher life, 144,
148.

Sign, definition of, 248, 252.

Simultaneity of sensations, 190 ff.

Sleep, cause of, 218, 224, 226 f.,
230; consciousness in, 215, 244;
function of, 216; heaviness in,
225; mantic character of, 247;
movements in, 223; necessary
to animal life, 216, 221 ; organ
of, 215, 222; sensation in, 241 ;
tractate on, 213 ff.

Smell, air affected by, 94; classifi-
cation of smells, 83, 173 ; ex-
halation, 155 ; inaccurate in
man, 82, 164; in air and water,
171, 177; medium required by,
74, 84 ; middle position of, 177 ;
nature of, 82 ff. ; relation to
flavour, 83, 164, 174; relation to
respiration, 175; 'sapid dry,'
172; theories of, 173 ff.

Soul, Alcmaeon on, 16 ; Anaxa-
goras on, 16; atomic theory of,
11 ; body related to, 6, 7, 9,
29, 40, 53, 58, 146; centralisa-
tion of, 274; Critias on, 16;
definition of, 45-52, 55, 56 ;
Democritus on, 11, 15; Dio-
genes on, 15; elements related
to, 33 f., 37, 38; Empedocles
on, 13 ; etymology of word, 17 ;
faculties of, 40, 51, 54, 57, 133 ;
final cause, 59 ; fire, 60 ; har-
mony, 26 f. ; Heraclitus on, 15 ;
Hippo on, 16; immortality of,
6, 7, 31, 47, 51 ; knowledge, 41 ;
Leucippus on, 11 ; life, 39, 49 ;
motion, 10, 19 ff., 30, 37; num-
ber-theory, 30, 32 ; nutrition,
50, 61 ff., 271 ; Plato on, 13,
51 ; pre- Aristotelian theories of,
10 ff., 13, 33 ; principle in plants,
41; reality, 126; separability
of, 6f., 31, 47, 51; substance,
42; Thales on, 15; unity of, 40,
51 ; Xenocrates on, 30.

Sound, of insects, 305 ; nature of,
75 ff.

Stimuli, excessive, 93, 102.

Substance, meanings of, 42, 44,
52.

Taste, accurate in man, 82 ; nature
of, 85 f . ; primary flavours, 87 ;
touch and, 139, 164.

Temperature, regulation of, 80.

Thales, soul kinetic, 15 ; pan-
psychism, 38.

Theophrastus, on sound, 75.

Theories of soul, history of, 11 ff.

Thought, vid. under Reason, defi-
nition of, 106 ; dependent on
will, 67 ; discursive, 29 : identi-
cal with object, 125 ; inde-
pendence of body, 6 ; image
necessary to, 6, 197; somatic,
105,

Time, 191.

Touch, accuracy of, in man, 82 ;
analogy to hearing, 79 ; direct
action of, 142 ; function of,
69; fundamental character of,
50, 52, 54-56, 139, 142, 143;

INDKX

3:iy

inodium of, S."), H\) 01 ; nature
(»f, SH (r., Kill; nr^'Hii of, HI);
tuuto and, CirK

Univrraals, niiture of, I ; in the
mind, H7.

Vision, lid. under Si^ht ; eon-
nceted with lire, \C){)', Denut-
crituH on, l.l.'i ; elleet t>n <»hject,
237 ; lOnipedooIea on, IfrJ ; eye
as organ of, 155 ; medium of,
141 ; nature of, 71 ; Fhito on,
161; theories of, 150(1'.

Voice, ilgnificant sound, 79 81.

Waking, <lelinition of, 214.
WhaleH, Hpout-organ in, 'JTi.
Will, kinetic aspect of reason,

12u-i:ji.

Windpipe, 309.
Words, symbols, 149.

Xenocrates, 30-33.

Youth, and old age, 270.

GLASGOW : PRINTED AC THE UNIVKRSITY PRBSS BY ROBEKi MACLKHOSE AND CO.

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