Aristotle
384-322 B.C.E. - Wrote in Greek
On the Soul
Written 350 B.C.E
Translated by J. A. Smith
On the Soul
By Aristotle
Book I
Part 1
Holding as we do that, while knowledge of any kind is a thing to be honoured
and prized, one kind of it may, either by reason of its greater exactness
or of a higher dignity and greater wonderfulness in its objects, be more
honourable and precious than another, on both accounts we should naturally
be led to place in the front rank the study of the soul. The knowledge
of the soul admittedly contributes greatly to the advance of truth in general,
and, above all, to our understanding of Nature, for the soul is in some
sense the principle of animal life. Our aim is to grasp and understand,
first its essential nature, and secondly its properties; of these some
are taught to be affections proper to the soul itself, while others are
considered to attach to the animal owing to the presence within it of
soul.
To attain any assured knowledge about the soul is one of the most
difficult things in the world. As the form of question which here presents
itself, viz. the question 'What is it?', recurs in other fields, it might
be supposed that there was some single method of inquiry applicable to
all objects whose essential nature (as we are endeavouring to ascertain
there is for derived properties the single method of demonstration); in
that case what we should have to seek for would be this unique method.
But if there is no such single and general method for solving the question
of essence, our task becomes still more difficult; in the case of each
different subject we shall have to determine the appropriate process of
investigation. If to this there be a clear answer, e.g. that the process
is demonstration or division, or some known method, difficulties and hesitations
still beset us-with what facts shall we begin the inquiry? For the facts
which form the starting-points in different subjects must be different,
as e.g. in the case of numbers and surfaces.
First, no doubt, it is necessary to determine in which of the summa
genera soul lies, what it is; is it 'a this-somewhat, 'a substance, or
is it a quale or a quantum, or some other of the remaining kinds of predicates
which we have distinguished? Further, does soul belong to the class of
potential existents, or is it not rather an actuality? Our answer to this
question is of the greatest importance.
We must consider also whether soul is divisible or is without parts,
and whether it is everywhere homogeneous or not; and if not homogeneous,
whether its various forms are different specifically or generically: up
to the present time those who have discussed and investigated soul seem
to have confined themselves to the human soul. We must be careful not to
ignore the question whether soul can be defined in a single unambiguous
formula, as is the case with animal, or whether we must not give a separate
formula for each of it, as we do for horse, dog, man, god (in the latter
case the 'universal' animal-and so too every other 'common predicate'-being
treated either as nothing at all or as a later product). Further, if what
exists is not a plurality of souls, but a plurality of parts of one soul,
which ought we to investigate first, the whole soul or its parts? (It is
also a difficult problem to decide which of these parts are in nature distinct
from one another.) Again, which ought we to investigate first, these parts
or their functions, mind or thinking, the faculty or the act of sensation,
and so on? If the investigation of the functions precedes that of the parts,
the further question suggests itself: ought we not before either to consider
the correlative objects, e.g. of sense or thought? It seems not only useful
for the discovery of the causes of the derived properties of substances
to be acquainted with the essential nature of those substances (as in mathematics
it is useful for the understanding of the property of the equality of the
interior angles of a triangle to two right angles to know the essential
nature of the straight and the curved or of the line and the plane) but
also conversely, for the knowledge of the essential nature of a substance
is largely promoted by an acquaintance with its properties: for, when we
are able to give an account conformable to experience of all or most of
the properties of a substance, we shall be in the most favourable position
to say something worth saying about the essential nature of that subject;
in all demonstration a definition of the essence is required as a starting-point,
so that definitions which do not enable us to discover the derived properties,
or which fail to facilitate even a conjecture about them, must obviously,
one and all, be dialectical and futile.
A further problem presented by the affections of soul is this:
are they all affections of the complex of body and soul, or is there any
one among them peculiar to the soul by itself? To determine this is indispensable
but difficult. If we consider the majority of them, there seems to be no
case in which the soul can act or be acted upon without involving the body;
e.g. anger, courage, appetite, and sensation generally. Thinking seems
the most probable exception; but if this too proves to be a form of imagination
or to be impossible without imagination, it too requires a body as a condition
of its existence. If there is any way of acting or being acted upon proper
to soul, soul will be capable of separate existence; if there is none,
its separate existence is impossible. In the latter case, it will be like
what is straight, which has many properties arising from the straightness
in it, e.g. that of touching a bronze sphere at a point, though straightness
divorced from the other constituents of the straight thing cannot touch
it in this way; it cannot be so divorced at all, since it is always found
in a body. It therefore seems that all the affections of soul involve a
body-passion, gentleness, fear, pity, courage, joy, loving, and hating;
in all these there is a concurrent affection of the body. In support of
this we may point to the fact that, while sometimes on the occasion of
violent and striking occurrences there is no excitement or fear felt, on
others faint and feeble stimulations produce these emotions, viz. when
the body is already in a state of tension resembling its condition when
we are angry. Here is a still clearer case: in the absence of any external
cause of terror we find ourselves experiencing the feelings of a man in
terror. From all this it is obvious that the affections of soul are enmattered
formulable essences.
Consequently their definitions ought to correspond, e.g. anger
should be defined as a certain mode of movement of such and such a body
(or part or faculty of a body) by this or that cause and for this or that
end. That is precisely why the study of the soul must fall within the science
of Nature, at least so far as in its affections it manifests this double
character. Hence a physicist would define an affection of soul differently
from a dialectician; the latter would define e.g. anger as the appetite
for returning pain for pain, or something like that, while the former would
define it as a boiling of the blood or warm substance surround the heart.
The latter assigns the material conditions, the former the form or formulable
essence; for what he states is the formulable essence of the fact, though
for its actual existence there must be embodiment of it in a material such
as is described by the other. Thus the essence of a house is assigned in
such a formula as 'a shelter against destruction by wind, rain, and heat';
the physicist would describe it as 'stones, bricks, and timbers'; but there
is a third possible description which would say that it was that form in
that material with that purpose or end. Which, then, among these is entitled
to be regarded as the genuine physicist? The one who confines himself to
the material, or the one who restricts himself to the formulable essence
alone? Is it not rather the one who combines both in a single formula?
If this is so, how are we to characterize the other two? Must we not say
that there is no type of thinker who concerns himself with those qualities
or attributes of the material which are in fact inseparable from the material,
and without attempting even in thought to separate them? The physicist
is he who concerns himself with all the properties active and passive of
bodies or materials thus or thus defined; attributes not considered as
being of this character he leaves to others, in certain cases it may be
to a specialist, e.g. a carpenter or a physician, in others (a) where they
are inseparable in fact, but are separable from any particular kind of
body by an effort of abstraction, to the mathematician, (b) where they
are separate both in fact and in thought from body altogether, to the First
Philosopher or metaphysician. But we must return from this digression,
and repeat that the affections of soul are inseparable from the material
substratum of animal life, to which we have seen that such affections,
e.g. passion and fear, attach, and have not the same mode of being as a
line or a plane.
Part 2
For our study of soul it is necessary, while formulating the problems
of which in our further advance we are to find the solutions, to call into
council the views of those of our predecessors who have declared any opinion
on this subject, in order that we may profit by whatever is sound in their
suggestions and avoid their errors.
The starting-point of our inquiry is an exposition of those characteristics
which have chiefly been held to belong to soul in its very nature. Two
characteristic marks have above all others been recognized as distinguishing
that which has soul in it from that which has not-movement and sensation.
It may be said that these two are what our predecessors have fixed upon
as characteristic of soul.
Some say that what originates movement is both pre-eminently and
primarily soul; believing that what is not itself moved cannot originate
movement in another, they arrived at the view that soul belongs to the
class of things in movement. This is what led Democritus to say that soul
is a sort of fire or hot substance; his 'forms' or atoms are infinite in
number; those which are spherical he calls fire and soul, and compares
them to the motes in the air which we see in shafts of light coming through
windows; the mixture of seeds of all sorts he calls the elements of the
whole of Nature (Leucippus gives a similar account); the spherical atoms
are identified with soul because atoms of that shape are most adapted to
permeate everywhere, and to set all the others moving by being themselves
in movement. This implies the view that soul is identical with what produces
movement in animals. That is why, further, they regard respiration as the
characteristic mark of life; as the environment compresses the bodies of
animals, and tends to extrude those atoms which impart movement to them,
because they themselves are never at rest, there must be a reinforcement
of these by similar atoms coming in from without in the act of respiration;
for they prevent the extrusion of those which are already within by counteracting
the compressing and consolidating force of the environment; and animals
continue to live only so long as they are able to maintain this
resistance.
The doctrine of the Pythagoreans seems to rest upon the same ideas;
some of them declared the motes in air, others what moved them, to be soul.
These motes were referred to because they are seen always in movement,
even in a complete calm.
The same tendency is shown by those who define soul as that which
moves itself; all seem to hold the view that movement is what is closest
to the nature of soul, and that while all else is moved by soul, it alone
moves itself. This belief arises from their never seeing anything originating
movement which is not first itself moved.
Similarly also Anaxagoras (and whoever agrees with him in saying
that mind set the whole in movement) declares the moving cause of things
to be soul. His position must, however, be distinguished from that of Democritus.
Democritus roundly identifies soul and mind, for he identifies what appears
with what is true-that is why he commends Homer for the phrase 'Hector
lay with thought distraught'; he does not employ mind as a special faculty
dealing with truth, but identifies soul and mind. What Anaxagoras says
about them is more obscure; in many places he tells us that the cause of
beauty and order is mind, elsewhere that it is soul; it is found, he says,
in all animals, great and small, high and low, but mind (in the sense of
intelligence) appears not to belong alike to all animals, and indeed not
even to all human beings.
All those, then, who had special regard to the fact that what has
soul in it is moved, adopted the view that soul is to be identified with
what is eminently originative of movement. All, on the other hand, who
looked to the fact that what has soul in it knows or perceives what is,
identify soul with the principle or principles of Nature, according as
they admit several such principles or one only. Thus Empedocles declares
that it is formed out of all his elements, each of them also being soul;
his words are:
For 'tis by Earth we see Earth, by Water Water,
By Ether Ether divine, by Fire destructive Fire,
By Love Love, and Hate by cruel Hate.
In the same way Plato in the Timaeus fashions soul out of his elements;
for like, he holds, is known by like, and things are formed out of the
principles or elements, so that soul must be so too. Similarly also in
his lectures 'On Philosophy' it was set forth that the Animal-itself is
compounded of the Idea itself of the One together with the primary length,
breadth, and depth, everything else, the objects of its perception, being
similarly constituted. Again he puts his view in yet other terms: Mind
is the monad, science or knowledge the dyad (because it goes undeviatingly
from one point to another), opinion the number of the plane, sensation
the number of the solid; the numbers are by him expressly identified with
the Forms themselves or principles, and are formed out of the elements;
now things are apprehended either by mind or science or opinion or sensation,
and these same numbers are the Forms of things.
Some thinkers, accepting both premisses, viz. that the soul is
both originative of movement and cognitive, have compounded it of both
and declared the soul to be a self-moving number.
As to the nature and number of the first principles opinions differ.
The difference is greatest between those who regard them as corporeal and
those who regard them as incorporeal, and from both dissent those who make
a blend and draw their principles from both sources. The number of principles
is also in dispute; some admit one only, others assert several. There is
a consequent diversity in their several accounts of soul; they assume,
naturally enough, that what is in its own nature originative of movement
must be among what is primordial. That has led some to regard it as fire,
for fire is the subtlest of the elements and nearest to incorporeality;
further, in the most primary sense, fire both is moved and originates movement
in all the others.
Democritus has expressed himself more ingeniously than the rest
on the grounds for ascribing each of these two characters to soul; soul
and mind are, he says, one and the same thing, and this thing must be one
of the primary and indivisible bodies, and its power of originating movement
must be due to its fineness of grain and the shape of its atoms; he says
that of all the shapes the spherical is the most mobile, and that this
is the shape of the particles of fire and mind.
Anaxagoras, as we said above, seems to distinguish between soul
and mind, but in practice he treats them as a single substance, except
that it is mind that he specially posits as the principle of all things;
at any rate what he says is that mind alone of all that is simple, unmixed,
and pure. He assigns both characteristics, knowing and origination of movement,
to the same principle, when he says that it was mind that set the whole
in movement.
Thales, too, to judge from what is recorded about him, seems to
have held soul to be a motive force, since he said that the magnet has
a soul in it because it moves the iron.
Diogenes (and others) held the soul to be air because he believed
air to be finest in grain and a first principle; therein lay the grounds
of the soul's powers of knowing and originating movement. As the primordial
principle from which all other things are derived, it is cognitive; as
finest in grain, it has the power to originate movement.
Heraclitus too says that the first principle-the 'warm exhalation'
of which, according to him, everything else is composed-is soul; further,
that this exhalation is most incorporeal and in ceaseless flux; that what
is in movement requires that what knows it should be in movement; and that
all that is has its being essentially in movement (herein agreeing with
the majority).
Alcmaeon also seems to have held a similar view about soul; he
says that it is immortal because it resembles 'the immortals,' and that
this immortality belongs to it in virtue of its ceaseless movement; for
all the 'things divine,' moon, sun, the planets, and the whole heavens,
are in perpetual movement.
of More superficial writers, some, e.g. Hippo, have pronounced
it to be water; they seem to have argued from the fact that the seed of
all animals is fluid, for Hippo tries to refute those who say that the
soul is blood, on the ground that the seed, which is the primordial soul,
is not blood.
Another group (Critias, for example) did hold it to be blood; they
take perception to be the most characteristic attribute of soul, and hold
that perceptiveness is due to the nature of blood.
Each of the elements has thus found its partisan, except earth-earth
has found no supporter unless we count as such those who have declared
soul to be, or to be compounded of, all the elements. All, then, it may
be said, characterize the soul by three marks, Movement, Sensation, Incorporeality,
and each of these is traced back to the first principles. That is why (with
one exception) all those who define the soul by its power of knowing make
it either an element or constructed out of the elements. The language they
all use is similar; like, they say, is known by like; as the soul knows
everything, they construct it out of all the principles. Hence all those
who admit but one cause or element, make the soul also one (e.g. fire or
air), while those who admit a multiplicity of principles make the soul
also multiple. The exception is Anaxagoras; he alone says that mind is
impassible and has nothing in common with anything else. But, if this is
so, how or in virtue of what cause can it know? That Anaxagoras has not
explained, nor can any answer be inferred from his words. All who acknowledge
pairs of opposites among their principles, construct the soul also out
of these contraries, while those who admit as principles only one contrary
of each pair, e.g. either hot or cold, likewise make the soul some one
of these. That is why, also, they allow themselves to be guided by the
names; those who identify soul with the hot argue that sen (to live) is
derived from sein (to boil), while those who identify it with the cold
say that soul (psuche) is so called from the process of respiration and
(katapsuxis). Such are the traditional opinions concerning soul, together
with the grounds on which they are maintained.
Part 3
We must begin our examination with movement; for doubtless, not
only is it false that the essence of soul is correctly described by those
who say that it is what moves (or is capable of moving) itself, but it
is an impossibility that movement should be even an attribute of
it.
We have already pointed out that there is no necessity that what
originates movement should itself be moved. There are two senses in which
anything may be moved-either (a) indirectly, owing to something other than
itself, or (b) directly, owing to itself. Things are 'indirectly moved'
which are moved as being contained in something which is moved, e.g. sailors
in a ship, for they are moved in a different sense from that in which the
ship is moved; the ship is 'directly moved', they are 'indirectly moved',
because they are in a moving vessel. This is clear if we consider their
limbs; the movement proper to the legs (and so to man) is walking, and
in this case the sailors tare not walking. Recognizing the double sense
of 'being moved', what we have to consider now is whether the soul is 'directly
moved' and participates in such direct movement.
There are four species of movement-locomotion, alteration, diminution,
growth; consequently if the soul is moved, it must be moved with one or
several or all of these species of movement. Now if its movement is not
incidental, there must be a movement natural to it, and, if so, as all
the species enumerated involve place, place must be natural to it. But
if the essence of soul be to move itself, its being moved cannot be incidental
to-as it is to what is white or three cubits long; they too can be moved,
but only incidentally-what is moved is that of which 'white' and 'three
cubits long' are the attributes, the body in which they inhere; hence they
have no place: but if the soul naturally partakes in movement, it follows
that it must have a place.
Further, if there be a movement natural to the soul, there must
be a counter-movement unnatural to it, and conversely. The same applies
to rest as well as to movement; for the terminus ad quem of a thing's natural
movement is the place of its natural rest, and similarly the terminus ad
quem of its enforced movement is the place of its enforced rest. But what
meaning can be attached to enforced movements or rests of the soul, it
is difficult even to imagine.
Further, if the natural movement of the soul be upward, the soul
must be fire; if downward, it must be earth; for upward and downward movements
are the definitory characteristics of these bodies. The same reasoning
applies to the intermediate movements, termini, and bodies. Further, since
the soul is observed to originate movement in the body, it is reasonable
to suppose that it transmits to the body the movements by which it itself
is moved, and so, reversing the order, we may infer from the movements
of the body back to similar movements of the soul. Now the body is moved
from place to place with movements of locomotion. Hence it would follow
that the soul too must in accordance with the body change either its place
as a whole or the relative places of its parts. This carries with it the
possibility that the soul might even quit its body and re-enter it, and
with this would be involved the possibility of a resurrection of animals
from the dead. But, it may be contended, the soul can be moved indirectly
by something else; for an animal can be pushed out of its course. Yes,
but that to whose essence belongs the power of being moved by itself, cannot
be moved by something else except incidentally, just as what is good by
or in itself cannot owe its goodness to something external to it or to
some end to which it is a means.
If the soul is moved, the most probable view is that what moves
it is sensible things.
We must note also that, if the soul moves itself, it must be the
mover itself that is moved, so that it follows that if movement is in every
case a displacement of that which is in movement, in that respect in which
it is said to be moved, the movement of the soul must be a departure from
its essential nature, at least if its self-movement is essential to it,
not incidental.
Some go so far as to hold that the movements which the soul imparts
to the body in which it is are the same in kind as those with which it
itself is moved. An example of this is Democritus, who uses language like
that of the comic dramatist Philippus, who accounts for the movements that
Daedalus imparted to his wooden Aphrodite by saying that he poured quicksilver
into it; similarly Democritus says that the spherical atoms which according
to him constitute soul, owing to their own ceaseless movements draw the
whole body after them and so produce its movements. We must urge the question
whether it is these very same atoms which produce rest also-how they could
do so, it is difficult and even impossible to say. And, in general, we
may object that it is not in this way that the soul appears to originate
movement in animals-it is through intention or process of
thinking.
It is in the same fashion that the Timaeus also tries to give a
physical account of how the soul moves its body; the soul, it is there
said, is in movement, and so owing to their mutual implication moves the
body also. After compounding the soul-substance out of the elements and
dividing it in accordance with the harmonic numbers, in order that it may
possess a connate sensibility for 'harmony' and that the whole may move
in movements well attuned, the Demiurge bent the straight line into a circle;
this single circle he divided into two circles united at two common points;
one of these he subdivided into seven circles. All this implies that the
movements of the soul are identified with the local movements of the
heavens.
Now, in the first place, it is a mistake to say that the soul is
a spatial magnitude. It is evident that Plato means the soul of the whole
to be like the sort of soul which is called mind not like the sensitive
or the desiderative soul, for the movements of neither of these are circular.
Now mind is one and continuous in the sense in which the process of thinking
is so, and thinking is identical with the thoughts which are its parts;
these have a serial unity like that of number, not a unity like that of
a spatial magnitude. Hence mind cannot have that kind of unity either;
mind is either without parts or is continuous in some other way than that
which characterizes a spatial magnitude. How, indeed, if it were a spatial
magnitude, could mind possibly think? Will it think with any one indifferently
of its parts? In this case, the 'part' must be understood either in the
sense of a spatial magnitude or in the sense of a point (if a point can
be called a part of a spatial magnitude). If we accept the latter alternative,
the points being infinite in number, obviously the mind can never exhaustively
traverse them; if the former, the mind must think the same thing over and
over again, indeed an infinite number of times (whereas it is manifestly
possible to think a thing once only). If contact of any part whatsoever
of itself with the object is all that is required, why need mind move in
a circle, or indeed possess magnitude at all? On the other hand, if contact
with the whole circle is necessary, what meaning can be given to the contact
of the parts? Further, how could what has no parts think what has parts,
or what has parts think what has none? We must identify the circle referred
to with mind; for it is mind whose movement is thinking, and it is the
circle whose movement is revolution, so that if thinking is a movement
of revolution, the circle which has this characteristic movement must be
mind.
If the circular movement is eternal, there must be something which
mind is always thinking-what can this be? For all practical processes of
thinking have limits-they all go on for the sake of something outside the
process, and all theoretical processes come to a close in the same way
as the phrases in speech which express processes and results of thinking.
Every such linguistic phrase is either definitory or demonstrative. Demonstration
has both a starting-point and may be said to end in a conclusion or inferred
result; even if the process never reaches final completion, at any rate
it never returns upon itself again to its starting-point, it goes on assuming
a fresh middle term or a fresh extreme, and moves straight forward, but
circular movement returns to its starting-point. Definitions, too, are
closed groups of terms.
Further, if the same revolution is repeated, mind must repeatedly
think the same object.
Further, thinking has more resemblance to a coming to rest or arrest
than to a movement; the same may be said of inferring.
It might also be urged that what is difficult and enforced is incompatible
with blessedness; if the movement of the soul is not of its essence, movement
of the soul must be contrary to its nature. It must also be painful for
the soul to be inextricably bound up with the body; nay more, if, as is
frequently said and widely accepted, it is better for mind not to be embodied,
the union must be for it undesirable.
Further, the cause of the revolution of the heavens is left obscure.
It is not the essence of soul which is the cause of this circular movement-that
movement is only incidental to soul-nor is, a fortiori, the body its cause.
Again, it is not even asserted that it is better that soul should be so
moved; and yet the reason for which God caused the soul to move in a circle
can only have been that movement was better for it than rest, and movement
of this kind better than any other. But since this sort of consideration
is more appropriate to another field of speculation, let us dismiss it
for the present.
The view we have just been examining, in company with most theories
about the soul, involves the following absurdity: they all join the soul
to a body, or place it in a body, without adding any specification of the
reason of their union, or of the bodily conditions required for it. Yet
such explanation can scarcely be omitted; for some community of nature
is presupposed by the fact that the one acts and the other is acted upon,
the one moves and the other is moved; interaction always implies a special
nature in the two interagents. All, however, that these thinkers do is
to describe the specific characteristics of the soul; they do not try to
determine anything about the body which is to contain it, as if it were
possible, as in the Pythagorean myths, that any soul could be clothed upon
with any body-an absurd view, for each body seems to have a form and shape
of its own. It is as absurd as to say that the art of carpentry could embody
itself in flutes; each art must use its tools, each soul its
body.
Part 4
There is yet another theory about soul, which has commended itself
to many as no less probable than any of those we have hitherto mentioned,
and has rendered public account of itself in the court of popular discussion.
Its supporters say that the soul is a kind of harmony, for (a) harmony
is a blend or composition of contraries, and (b) the body is compounded
out of contraries. Harmony, however, is a certain proportion or composition
of the constituents blended, and soul can be neither the one nor the other
of these. Further, the power of originating movement cannot belong to a
harmony, while almost all concur in regarding this as a principal attribute
of soul. It is more appropriate to call health (or generally one of the
good states of the body) a harmony than to predicate it of the soul. The
absurdity becomes most apparent when we try to attribute the active and
passive affections of the soul to a harmony; the necessary readjustment
of their conceptions is difficult. Further, in using the word 'harmony'
we have one or other of two cases in our mind; the most proper sense is
in relation to spatial magnitudes which have motion and position, where
harmony means the disposition and cohesion of their parts in such a manner
as to prevent the introduction into the whole of anything homogeneous with
it, and the secondary sense, derived from the former, is that in which
it means the ratio between the constituents so blended; in neither of these
senses is it plausible to predicate it of soul. That soul is a harmony
in the sense of the mode of composition of the parts of the body is a view
easily refutable; for there are many composite parts and those variously
compounded; of what bodily part is mind or the sensitive or the appetitive
faculty the mode of composition? And what is the mode of composition which
constitutes each of them? It is equally absurd to identify the soul with
the ratio of the mixture; for the mixture which makes flesh has a different
ratio between the elements from that which makes bone. The consequence
of this view will therefore be that distributed throughout the whole body
there will be many souls, since every one of the bodily parts is a different
mixture of the elements, and the ratio of mixture is in each case a harmony,
i.e. a soul.
From Empedocles at any rate we might demand an answer to the following
question for he says that each of the parts of the body is what it is in
virtue of a ratio between the elements: is the soul identical with this
ratio, or is it not rather something over and above this which is formed
in the parts? Is love the cause of any and every mixture, or only of those
that are in the right ratio? Is love this ratio itself, or is love something
over and above this? Such are the problems raised by this account. But,
on the other hand, if the soul is different from the mixture, why does
it disappear at one and the same moment with that relation between the
elements which constitutes flesh or the other parts of the animal body?
Further, if the soul is not identical with the ratio of mixture, and it
is consequently not the case that each of the parts has a soul, what is
that which perishes when the soul quits the body?
That the soul cannot either be a harmony, or be moved in a circle,
is clear from what we have said. Yet that it can be moved incidentally
is, as we said above, possible, and even that in a sense it can move itself,
i.e. in the sense that the vehicle in which it is can be moved, and moved
by it; in no other sense can the soul be moved in space.
More legitimate doubts might remain as to its movement in view
of the following facts. We speak of the soul as being pained or pleased,
being bold or fearful, being angry, perceiving, thinking. All these are
regarded as modes of movement, and hence it might be inferred that the
soul is moved. This, however, does not necessarily follow. We may admit
to the full that being pained or pleased, or thinking, are movements (each
of them a 'being moved'), and that the movement is originated by the soul.
For example we may regard anger or fear as such and such movements of the
heart, and thinking as such and such another movement of that organ, or
of some other; these modifications may arise either from changes of place
in certain parts or from qualitative alterations (the special nature of
the parts and the special modes of their changes being for our present
purpose irrelevant). Yet to say that it is the soul which is angry is as
inexact as it would be to say that it is the soul that weaves webs or builds
houses. It is doubtless better to avoid saying that the soul pities or
learns or thinks and rather to say that it is the man who does this with
his soul. What we mean is not that the movement is in the soul, but that
sometimes it terminates in the soul and sometimes starts from it, sensation
e.g. coming from without inwards, and reminiscence starting from the soul
and terminating with the movements, actual or residual, in the sense
organs.
The case of mind is different; it seems to be an independent substance
implanted within the soul and to be incapable of being destroyed. If it
could be destroyed at all, it would be under the blunting influence of
old age. What really happens in respect of mind in old age is, however,
exactly parallel to what happens in the case of the sense organs; if the
old man could recover the proper kind of eye, he would see just as well
as the young man. The incapacity of old age is due to an affection not
of the soul but of its vehicle, as occurs in drunkenness or disease. Thus
it is that in old age the activity of mind or intellectual apprehension
declines only through the decay of some other inward part; mind itself
is impassible. Thinking, loving, and hating are affections not of mind,
but of that which has mind, so far as it has it. That is why, when this
vehicle decays, memory and love cease; they were activities not of mind,
but of the composite which has perished; mind is, no doubt, something more
divine and impassible. That the soul cannot be moved is therefore clear
from what we have said, and if it cannot be moved at all, manifestly it
cannot be moved by itself.
Of all the opinions we have enumerated, by far the most unreasonable
is that which declares the soul to be a self-moving number; it involves
in the first place all the impossibilities which follow from regarding
the soul as moved, and in the second special absurdities which follow from
calling it a number. How we to imagine a unit being moved? By what agency?
What sort of movement can be attributed to what is without parts or internal
differences? If the unit is both originative of movement and itself capable
of being moved, it must contain difference.
Further, since they say a moving line generates a surface and a
moving point a line, the movements of the psychic units must be lines (for
a point is a unit having position, and the number of the soul is, of course,
somewhere and has position).
Again, if from a number a number or a unit is subtracted, the remainder
is another number; but plants and many animals when divided continue to
live, and each segment is thought to retain the same kind of
soul.
It must be all the same whether we speak of units or corpuscles;
for if the spherical atoms of Democritus became points, nothing being retained
but their being a quantum, there must remain in each a moving and a moved
part, just as there is in what is continuous; what happens has nothing
to do with the size of the atoms, it depends solely upon their being a
quantum. That is why there must be something to originate movement in the
units. If in the animal what originates movement is the soul, so also must
it be in the case of the number, so that not the mover and the moved together,
but the mover only, will be the soul. But how is it possible for one of
the units to fulfil this function of originating movement? There must be
some difference between such a unit and all the other units, and what difference
can there be between one placed unit and another except a difference of
position? If then, on the other hand, these psychic units within the body
are different from the points of the body, there will be two sets of units
both occupying the same place; for each unit will occupy a point. And yet,
if there can be two, why cannot there be an infinite number? For if things
can occupy an indivisible lace, they must themselves be indivisible. If,
on the other hand, the points of the body are identical with the units
whose number is the soul, or if the number of the points in the body is
the soul, why have not all bodies souls? For all bodies contain points
or an infinity of points.
Further, how is it possible for these points to be isolated or
separated from their bodies, seeing that lines cannot be resolved into
points?
Part 5
The result is, as we have said, that this view, while on the one
side identical with that of those who maintain that soul is a subtle kind
of body, is on the other entangled in the absurdity peculiar to Democritus'
way of describing the manner in which movement is originated by soul. For
if the soul is present throughout the whole percipient body, there must,
if the soul be a kind of body, be two bodies in the same place; and for
those who call it a number, there must be many points at one point, or
every body must have a soul, unless the soul be a different sort of number-other,
that is, than the sum of the points existing in a body. Another consequence
that follows is that the animal must be moved by its number precisely in
the way that Democritus explained its being moved by his spherical psychic
atoms. What difference does it make whether we speak of small spheres or
of large units, or, quite simply, of units in movement? One way or another,
the movements of the animal must be due to their movements. Hence those
who combine movement and number in the same subject lay themselves open
to these and many other similar absurdities. It is impossible not only
that these characters should give the definition of soul-it is impossible
that they should even be attributes of it. The point is clear if the attempt
be made to start from this as the account of soul and explain from it the
affections and actions of the soul, e.g. reasoning, sensation, pleasure,
pain, &c. For, to repeat what we have said earlier, movement and number
do not facilitate even conjecture about the derivative properties of
soul.
Such are the three ways in which soul has traditionally been defined;
one group of thinkers declared it to be that which is most originative
of movement because it moves itself, another group to be the subtlest and
most nearly incorporeal of all kinds of body. We have now sufficiently
set forth the difficulties and inconsistencies to which these theories
are exposed. It remains now to examine the doctrine that soul is composed
of the elements.
The reason assigned for this doctrine is that thus the soul may
perceive or come to know everything that is, but the theory necessarily
involves itself in many impossibilities. Its upholders assume that like
is known only by like, and imagine that by declaring the soul to be composed
of the elements they succeed in identifying the soul with all the things
it is capable of apprehending. But the elements are not the only things
it knows; there are many others, or, more exactly, an infinite number of
others, formed out of the elements. Let us admit that the soul knows or
perceives the elements out of which each of these composites is made up;
but by what means will it know or perceive the composite whole, e.g. what
God, man, flesh, bone (or any other compound) is? For each is, not merely
the elements of which it is composed, but those elements combined in a
determinate mode or ratio, as Empedocles himself says of
bone,
The kindly Earth in its broad-bosomed moulds
Won of clear Water two parts out of eight, And four of
Fire; and so white bones were formed.
Nothing, therefore, will be gained by the presence of the elements
in the soul, unless there be also present there the various formulae of
proportion and the various compositions in accordance with them. Each element
will indeed know its fellow outside, but there will be no knowledge of
bone or man, unless they too are present in the constitution of the soul.
The impossibility of this needs no pointing out; for who would suggest
that stone or man could enter into the constitution of the soul? The same
applies to 'the good' and 'the not-good', and so on.
Further, the word 'is' has many meanings: it may be used of a 'this'
or substance, or of a quantum, or of a quale, or of any other of the kinds
of predicates we have distinguished. Does the soul consist of all of these
or not? It does not appear that all have common elements. Is the soul formed
out of those elements alone which enter into substances? so how will it
be able to know each of the other kinds of thing? Will it be said that
each kind of thing has elements or principles of its own, and that the
soul is formed out of the whole of these? In that case, the soul must be
a quantum and a quale and a substance. But all that can be made out of
the elements of a quantum is a quantum, not a substance. These (and others
like them) are the consequences of the view that the soul is composed of
all the elements.
It is absurd, also, to say both (a) that like is not capable of
being affected by like, and (b) that like is perceived or known by like,
for perceiving, and also both thinking and knowing, are, on their own assumption,
ways of being affected or moved.
There are many puzzles and difficulties raised by saying, as Empedocles
does, that each set of things is known by means of its corporeal elements
and by reference to something in soul which is like them, and additional
testimony is furnished by this new consideration; for all the parts of
the animal body which consist wholly of earth such as bones, sinews, and
hair seem to be wholly insensitive and consequently not perceptive even
of objects earthy like themselves, as they ought to have
been.
Further, each of the principles will have far more ignorance than
knowledge, for though each of them will know one thing, there will be many
of which it will be ignorant. Empedocles at any rate must conclude that
his God is the least intelligent of all beings, for of him alone is it
true that there is one thing, Strife, which he does not know, while there
is nothing which mortal beings do not know, for ere is nothing which does
not enter into their composition.
In general, we may ask, Why has not everything a soul, since everything
either is an element, or is formed out of one or several or all of the
elements? Each must certainly know one or several or
all.
The problem might also be raised, What is that which unifies the
elements into a soul? The elements correspond, it would appear, to the
matter; what unites them, whatever it is, is the supremely important factor.
But it is impossible that there should be something superior to, and dominant
over, the soul (and a fortiori over the mind); it is reasonable to hold
that mind is by nature most primordial and dominant, while their statement
that it is the elements which are first of all that
is.
All, both those who assert that the soul, because of its knowledge
or perception of what is compounded out of the elements, and is those who
assert that it is of all things the most originative of movement, fail
to take into consideration all kinds of soul. In fact (1) not all beings
that perceive can originate movement; there appear to be certain animals
which stationary, and yet local movement is the only one, so it seems,
which the soul originates in animals. And (2) the same object-on holds
against all those who construct mind and the perceptive faculty out of
the elements; for it appears that plants live, and yet are not endowed
with locomotion or perception, while a large number of animals are without
discourse of reason. Even if these points were waived and mind admitted
to be a part of the soul (and so too the perceptive faculty), still, even
so, there would be kinds and parts of soul of which they had failed to
give any account.
The same objection lies against the view expressed in the 'Orphic'
poems: there it is said that the soul comes in from the whole when breathing
takes place, being borne in upon the winds. Now this cannot take place
in the case of plants, nor indeed in the case of certain classes of animal,
for not all classes of animal breathe. This fact has escaped the notice
of the holders of this view.
If we must construct the soul out of the elements, there is no
necessity to suppose that all the elements enter into its construction;
one element in each pair of contraries will suffice to enable it to know
both that element itself and its contrary. By means of the straight line
we know both itself and the curved-the carpenter's rule enables us to test
both-but what is curved does not enable us to distinguish either itself
or the straight. Certain thinkers say that soul is intermingled in the
whole universe, and it is perhaps for that reason that Thales came to the
opinion that all things are full of gods. This presents some difficulties:
Why does the soul when it resides in air or fire not form an animal, while
it does so when it resides in mixtures of the elements, and that although
it is held to be of higher quality when contained in the former? (One might
add the question, why the soul in air is maintained to be higher and more
immortal than that in animals.) Both possible ways of replying to the former
question lead to absurdity or paradox; for it is beyond paradox to say
that fire or air is an animal, and it is absurd to refuse the name of animal
to what has soul in it. The opinion that the elements have soul in them
seems to have arisen from the doctrine that a whole must be homogeneous
with its parts. If it is true that animals become animate by drawing into
themselves a portion of what surrounds them, the partisans of this view
are bound to say that the soul of the Whole too is homogeneous with all
its parts. If the air sucked in is homogeneous, but soul heterogeneous,
clearly while some part of soul will exist in the inbreathed air, some
other part will not. The soul must either be homogeneous, or such that
there are some parts of the Whole in which it is not to be
found.
From what has been said it is now clear that knowing as an attribute
of soul cannot be explained by soul's being composed of the elements, and
that it is neither sound nor true to speak of soul as moved. But since
(a) knowing, perceiving, opining, and further (b) desiring, wishing, and
generally all other modes of appetition, belong to soul, and (c) the local
movements of animals, and (d) growth, maturity, and decay are produced
by the soul, we must ask whether each of these is an attribute of the soul
as a whole, i.e. whether it is with the whole soul we think, perceive,
move ourselves, act or are acted upon, or whether each of them requires
a different part of the soul? So too with regard to life. Does it depend
on one of the parts of soul? Or is it dependent on more than one? Or on
all? Or has it some quite other cause?
Some hold that the soul is divisible, and that one part thinks,
another desires. If, then, its nature admits of its being divided, what
can it be that holds the parts together? Surely not the body; on the contrary
it seems rather to be the soul that holds the body together; at any rate
when the soul departs the body disintegrates and decays. If, then, there
is something else which makes the soul one, this unifying agency would
have the best right to the name of soul, and we shall have to repeat for
it the question: Is it one or multipartite? If it is one, why not at once
admit that 'the soul' is one? If it has parts, once more the question must
be put: What holds its parts together, and so ad infinitum?
The question might also be raised about the parts of the soul:
What is the separate role of each in relation to the body? For, if the
whole soul holds together the whole body, we should expect each part of
the soul to hold together a part of the body. But this seems an impossibility;
it is difficult even to imagine what sort of bodily part mind will hold
together, or how it will do this.
It is a fact of observation that plants and certain insects go
on living when divided into segments; this means that each of the segments
has a soul in it identical in species, though not numerically identical
in the different segments, for both of the segments for a time possess
the power of sensation and local movement. That this does not last is not
surprising, for they no longer possess the organs necessary for self-maintenance.
But, all the same, in each of the bodily parts there are present all the
parts of soul, and the souls so present are homogeneous with one another
and with the whole; this means that the several parts of the soul are indisseverable
from one another, although the whole soul is divisible. It seems also that
the principle found in plants is also a kind of soul; for this is the only
principle which is common to both animals and plants; and this exists in
isolation from the principle of sensation, though there nothing which has
the latter without the former.
On the Soul
By Aristotle
Book II
Part 1
Let the foregoing suffice as our account of the views concerning the soul
which have been handed on by our predecessors; let us now dismiss them
and make as it were a completely fresh start, endeavouring to give a precise
answer to the question, What is soul? i.e. to formulate the most general
possible definition of it.
We are in the habit of recognizing, as one determinate kind of
what is, substance, and that in several senses, (a) in the sense of matter
or that which in itself is not 'a this', and (b) in the sense of form or
essence, which is that precisely in virtue of which a thing is called 'a
this', and thirdly (c) in the sense of that which is compounded of both
(a) and (b). Now matter is potentiality, form actuality; of the latter
there are two grades related to one another as e.g. knowledge to the exercise
of knowledge.
Among substances are by general consent reckoned bodies and especially
natural bodies; for they are the principles of all other bodies. Of natural
bodies some have life in them, others not; by life we mean self-nutrition
and growth (with its correlative decay). It follows that every natural
body which has life in it is a substance in the sense of a
composite.
But since it is also a body of such and such a kind, viz. having
life, the body cannot be soul; the body is the subject or matter, not what
is attributed to it. Hence the soul must be a substance in the sense of
the form of a natural body having life potentially within it. But substance
is actuality, and thus soul is the actuality of a body as above characterized.
Now the word actuality has two senses corresponding respectively to the
possession of knowledge and the actual exercise of knowledge. It is obvious
that the soul is actuality in the first sense, viz. that of knowledge as
possessed, for both sleeping and waking presuppose the existence of soul,
and of these waking corresponds to actual knowing, sleeping to knowledge
possessed but not employed, and, in the history of the individual, knowledge
comes before its employment or exercise.
That is why the soul is the first grade of actuality of a natural
body having life potentially in it. The body so described is a body which
is organized. The parts of plants in spite of their extreme simplicity
are 'organs'; e.g. the leaf serves to shelter the pericarp, the pericarp
to shelter the fruit, while the roots of plants are analogous to the mouth
of animals, both serving for the absorption of food. If, then, we have
to give a general formula applicable to all kinds of soul, we must describe
it as the first grade of actuality of a natural organized body. That is
why we can wholly dismiss as unnecessary the question whether the soul
and the body are one: it is as meaningless as to ask whether the wax and
the shape given to it by the stamp are one, or generally the matter of
a thing and that of which it is the matter. Unity has many senses (as many
as 'is' has), but the most proper and fundamental sense of both is the
relation of an actuality to that of which it is the actuality. We have
now given an answer to the question, What is soul?-an answer which applies
to it in its full extent. It is substance in the sense which corresponds
to the definitive formula of a thing's essence. That means that it is 'the
essential whatness' of a body of the character just assigned. Suppose that
what is literally an 'organ', like an axe, were a natural body, its 'essential
whatness', would have been its essence, and so its soul; if this disappeared
from it, it would have ceased to be an axe, except in name. As it is, it
is just an axe; it wants the character which is required to make its whatness
or formulable essence a soul; for that, it would have had to be a natural
body of a particular kind, viz. one having in itself the power of setting
itself in movement and arresting itself. Next, apply this doctrine in the
case of the 'parts' of the living body. Suppose that the eye were an animal-sight
would have been its soul, for sight is the substance or essence of the
eye which corresponds to the formula, the eye being merely the matter of
seeing; when seeing is removed the eye is no longer an eye, except in name-it
is no more a real eye than the eye of a statue or of a painted figure.
We must now extend our consideration from the 'parts' to the whole living
body; for what the departmental sense is to the bodily part which is its
organ, that the whole faculty of sense is to the whole sensitive body as
such.
We must not understand by that which is 'potentially capable of
living' what has lost the soul it had, but only what still retains it;
but seeds and fruits are bodies which possess the qualification. Consequently,
while waking is actuality in a sense corresponding to the cutting and the
seeing, the soul is actuality in the sense corresponding to the power of
sight and the power in the tool; the body corresponds to what exists in
potentiality; as the pupil plus the power of sight constitutes the eye,
so the soul plus the body constitutes the animal.
From this it indubitably follows that the soul is inseparable from
its body, or at any rate that certain parts of it are (if it has parts)
for the actuality of some of them is nothing but the actualities of their
bodily parts. Yet some may be separable because they are not the actualities
of any body at all. Further, we have no light on the problem whether the
soul may not be the actuality of its body in the sense in which the sailor
is the actuality of the ship.
This must suffice as our sketch or outline determination of the
nature of soul.
Part 2
Since what is clear or logically more evident emerges from what
in itself is confused but more observable by us, we must reconsider our
results from this point of view. For it is not enough for a definitive
formula to express as most now do the mere fact; it must include and exhibit
the ground also. At present definitions are given in a form analogous to
the conclusion of a syllogism; e.g. What is squaring? The construction
of an equilateral rectangle equal to a given oblong rectangle. Such a definition
is in form equivalent to a conclusion. One that tells us that squaring
is the discovery of a line which is a mean proportional between the two
unequal sides of the given rectangle discloses the ground of what is
defined.
We resume our inquiry from a fresh starting-point by calling attention
to the fact that what has soul in it differs from what has not, in that
the former displays life. Now this word has more than one sense, and provided
any one alone of these is found in a thing we say that thing is living.
Living, that is, may mean thinking or perception or local movement and
rest, or movement in the sense of nutrition, decay and growth. Hence we
think of plants also as living, for they are observed to possess in themselves
an originative power through which they increase or decrease in all spatial
directions; they grow up and down, and everything that grows increases
its bulk alike in both directions or indeed in all, and continues to live
so long as it can absorb nutriment.
This power of self-nutrition can be isolated from the other powers
mentioned, but not they from it-in mortal beings at least. The fact is
obvious in plants; for it is the only psychic power they
possess.
This is the originative power the possession of which leads us
to speak of things as living at all, but it is the possession of sensation
that leads us for the first time to speak of living things as animals;
for even those beings which possess no power of local movement but do possess
the power of sensation we call animals and not merely living
things.
The primary form of sense is touch, which belongs to all animals.
just as the power of self-nutrition can be isolated from touch and sensation
generally, so touch can be isolated from all other forms of sense. (By
the power of self-nutrition we mean that departmental power of the soul
which is common to plants and animals: all animals whatsoever are observed
to have the sense of touch.) What the explanation of these two facts is,
we must discuss later. At present we must confine ourselves to saying that
soul is the source of these phenomena and is characterized by them, viz.
by the powers of self-nutrition, sensation, thinking, and
motivity.
Is each of these a soul or a part of a soul? And if a part, a part
in what sense? A part merely distinguishable by definition or a part distinct
in local situation as well? In the case of certain of these powers, the
answers to these questions are easy, in the case of others we are puzzled
what to say. just as in the case of plants which when divided are observed
to continue to live though removed to a distance from one another (thus
showing that in their case the soul of each individual plant before division
was actually one, potentially many), so we notice a similar result in other
varieties of soul, i.e. in insects which have been cut in two; each of
the segments possesses both sensation and local movement; and if sensation,
necessarily also imagination and appetition; for, where there is sensation,
there is also pleasure and pain, and, where these, necessarily also
desire.
We have no evidence as yet about mind or the power to think; it
seems to be a widely different kind of soul, differing as what is eternal
from what is perishable; it alone is capable of existence in isolation
from all other psychic powers. All the other parts of soul, it is evident
from what we have said, are, in spite of certain statements to the contrary,
incapable of separate existence though, of course, distinguishable by definition.
If opining is distinct from perceiving, to be capable of opining and to
be capable of perceiving must be distinct, and so with all the other forms
of living above enumerated. Further, some animals possess all these parts
of soul, some certain of them only, others one only (this is what enables
us to classify animals); the cause must be considered later.' A similar
arrangement is found also within the field of the senses; some classes
of animals have all the senses, some only certain of them, others only
one, the most indispensable, touch.
Since the expression 'that whereby we live and perceive' has two
meanings, just like the expression 'that whereby we know'-that may mean
either (a) knowledge or (b) the soul, for we can speak of knowing by or
with either, and similarly that whereby we are in health may be either
(a) health or (b) the body or some part of the body; and since of the two
terms thus contrasted knowledge or health is the name of a form, essence,
or ratio, or if we so express it an actuality of a recipient matter-knowledge
of what is capable of knowing, health of what is capable of being made
healthy (for the operation of that which is capable of originating change
terminates and has its seat in what is changed or altered); further, since
it is the soul by or with which primarily we live, perceive, and think:-it
follows that the soul must be a ratio or formulable essence, not a matter
or subject. For, as we said, word substance has three meanings form, matter,
and the complex of both and of these three what is called matter is potentiality,
what is called form actuality. Since then the complex here is the living
thing, the body cannot be the actuality of the soul; it is the soul which
is the actuality of a certain kind of body. Hence the rightness of the
view that the soul cannot be without a body, while it csnnot he a body;
it is not a body but something relative to a body. That is why it is in
a body, and a body of a definite kind. It was a mistake, therefore, to
do as former thinkers did, merely to fit it into a body without adding
a definite specification of the kind or character of that body. Reflection
confirms the observed fact; the actuality of any given thing can only be
realized in what is already potentially that thing, i.e. in a matter of
its own appropriate to it. From all this it follows that soul is an actuality
or formulable essence of something that possesses a potentiality of being
besouled.
Part 3
Of the psychic powers above enumerated some kinds of living things,
as we have said, possess all, some less than all, others one only. Those
we have mentioned are the nutritive, the appetitive, the sensory, the locomotive,
and the power of thinking. Plants have none but the first, the nutritive,
while another order of living things has this plus the sensory. If any
order of living things has the sensory, it must also have the appetitive;
for appetite is the genus of which desire, passion, and wish are the species;
now all animals have one sense at least, viz. touch, and whatever has a
sense has the capacity for pleasure and pain and therefore has pleasant
and painful objects present to it, and wherever these are present, there
is desire, for desire is just appetition of what is pleasant. Further,
all animals have the sense for food (for touch is the sense for food);
the food of all living things consists of what is dry, moist, hot, cold,
and these are the qualities apprehended by touch; all other sensible qualities
are apprehended by touch only indirectly. Sounds, colours, and odours contribute
nothing to nutriment; flavours fall within the field of tangible qualities.
Hunger and thirst are forms of desire, hunger a desire for what is dry
and hot, thirst a desire for what is cold and moist; flavour is a sort
of seasoning added to both. We must later clear up these points, but at
present it may be enough to say that all animals that possess the sense
of touch have also appetition. The case of imagination is obscure; we must
examine it later. Certain kinds of animals possess in addition the power
of locomotion, and still another order of animate beings, i.e. man and
possibly another order like man or superior to him, the power of thinking,
i.e. mind. It is now evident that a single definition can be given of soul
only in the same sense as one can be given of figure. For, as in that case
there is no figure distinguishable and apart from triangle, &c., so here
there is no soul apart from the forms of soul just enumerated. It is true
that a highly general definition can be given for figure which will fit
all figures without expressing the peculiar nature of any figure. So here
in the case of soul and its specific forms. Hence it is absurd in this
and similar cases to demand an absolutely general definition which will
fail to express the peculiar nature of anything that is, or again, omitting
this, to look for separate definitions corresponding to each infima species.
The cases of figure and soul are exactly parallel; for the particulars
subsumed under the common name in both cases-figures and living beings-constitute
a series, each successive term of which potentially contains its predecessor,
e.g. the square the triangle, the sensory power the self-nutritive. Hence
we must ask in the case of each order of living things, What is its soul,
i.e. What is the soul of plant, animal, man? Why the terms are related
in this serial way must form the subject of later examination. But the
facts are that the power of perception is never found apart from the power
of self-nutrition, while-in plants-the latter is found isolated from the
former. Again, no sense is found apart from that of touch, while touch
is found by itself; many animals have neither sight, hearing, nor smell.
Again, among living things that possess sense some have the power of locomotion,
some not. Lastly, certain living beings-a small minority-possess calculation
and thought, for (among mortal beings) those which possess calculation
have all the other powers above mentioned, while the converse does not
hold-indeed some live by imagination alone, while others have not even
imagination. The mind that knows with immediate intuition presents a different
problem.
It is evident that the way to give the most adequate definition
of soul is to seek in the case of each of its forms for the most appropriate
definition.
Part 4
It is necessary for the student of these forms of soul first to
find a definition of each, expressive of what it is, and then to investigate
its derivative properties, &c. But if we are to express what each is, viz.
what the thinking power is, or the perceptive, or the nutritive, we must
go farther back and first give an account of thinking or perceiving, for
in the order of investigation the question of what an agent does precedes
the question, what enables it to do what it does. If this is correct, we
must on the same ground go yet another step farther back and have some
clear view of the objects of each; thus we must start with these objects,
e.g. with food, with what is perceptible, or with what is
intelligible.
It follows that first of all we must treat of nutrition and reproduction,
for the nutritive soul is found along with all the others and is the most
primitive and widely distributed power of soul, being indeed that one in
virtue of which all are said to have life. The acts in which it manifests
itself are reproduction and the use of food-reproduction, I say, because
for any living thing that has reached its normal development and which
is unmutilated, and whose mode of generation is not spontaneous, the most
natural act is the production of another like itself, an animal producing
an animal, a plant a plant, in order that, as far as its nature allows,
it may partake in the eternal and divine. That is the goal towards which
all things strive, that for the sake of which they do whatsoever their
nature renders possible. The phrase 'for the sake of which' is ambiguous;
it may mean either (a) the end to achieve which, or (b) the being in whose
interest, the act is done. Since then no living thing is able to partake
in what is eternal and divine by uninterrupted continuance (for nothing
perishable can for ever remain one and the same), it tries to achieve that
end in the only way possible to it, and success is possible in varying
degrees; so it remains not indeed as the self-same individual but continues
its existence in something like itself-not numerically but specifically
one.
The soul is the cause or source of the living body. The terms cause
and source have many senses. But the soul is the cause of its body alike
in all three senses which we explicitly recognize. It is (a) the source
or origin of movement, it is (b) the end, it is (c) the essence of the
whole living body.
That it is the last, is clear; for in everything the essence is
identical with the ground of its being, and here, in the case of living
things, their being is to live, and of their being and their living the
soul in them is the cause or source. Further, the actuality of whatever
is potential is identical with its formulable essence.
It is manifest that the soul is also the final cause of its body.
For Nature, like mind, always does whatever it does for the sake of something,
which something is its end. To that something corresponds in the case of
animals the soul and in this it follows the order of nature; all natural
bodies are organs of the soul. This is true of those that enter into the
constitution of plants as well as of those which enter into that of animals.
This shows that that the sake of which they are is soul. We must here recall
the two senses of 'that for the sake of which', viz. (a) the end to achieve
which, and (b) the being in whose interest, anything is or is
done.
We must maintain, further, that the soul is also the cause of the
living body as the original source of local movement. The power of locomotion
is not found, however, in all living things. But change of quality and
change of quantity are also due to the soul. Sensation is held to be a
qualitative alteration, and nothing except what has soul in it is capable
of sensation. The same holds of the quantitative changes which constitute
growth and decay; nothing grows or decays naturally except what feeds itself,
and nothing feeds itself except what has a share of soul in
it.
Empedocles is wrong in adding that growth in plants is to be explained,
the downward rooting by the natural tendency of earth to travel downwards,
and the upward branching by the similar natural tendency of fire to travel
upwards. For he misinterprets up and down; up and down are not for all
things what they are for the whole Cosmos: if we are to distinguish and
identify organs according to their functions, the roots of plants are analogous
to the head in animals. Further, we must ask what is the force that holds
together the earth and the fire which tend to travel in contrary directions;
if there is no counteracting force, they will be torn asunder; if there
is, this must be the soul and the cause of nutrition and growth. By some
the element of fire is held to be the cause of nutrition and growth, for
it alone of the primary bodies or elements is observed to feed and increase
itself. Hence the suggestion that in both plants and animals it is it which
is the operative force. A concurrent cause in a sense it certainly is,
but not the principal cause, that is rather the soul; for while the growth
of fire goes on without limit so long as there is a supply of fuel, in
the case of all complex wholes formed in the course of nature there is
a limit or ratio which determines their size and increase, and limit and
ratio are marks of soul but not of fire, and belong to the side of formulable
essence rather than that of matter.
Nutrition and reproduction are due to one and the same psychic
power. It is necessary first to give precision to our account of food,
for it is by this function of absorbing food that this psychic power is
distinguished from all the others. The current view is that what serves
as food to a living thing is what is contrary to it-not that in every pair
of contraries each is food to the other: to be food a contrary must not
only be transformable into the other and vice versa, it must also in so
doing increase the bulk of the other. Many a contrary is transformed into
its other and vice versa, where neither is even a quantum and so cannot
increase in bulk, e.g. an invalid into a healthy subject. It is clear that
not even those contraries which satisfy both the conditions mentioned above
are food to one another in precisely the same sense; water may be said
to feed fire, but not fire water. Where the members of the pair are elementary
bodies only one of the contraries, it would appear, can be said to feed
the other. But there is a difficulty here. One set of thinkers assert that
like fed, as well as increased in amount, by like. Another set, as we have
said, maintain the very reverse, viz. that what feeds and what is fed are
contrary to one another; like, they argue, is incapable of being affected
by like; but food is changed in the process of digestion, and change is
always to what is opposite or to what is intermediate. Further, food is
acted upon by what is nourished by it, not the other way round, as timber
is worked by a carpenter and not conversely; there is a change in the carpenter
but it is merely a change from not-working to working. In answering this
problem it makes all the difference whether we mean by 'the food' the 'finished'
or the 'raw' product. If we use the word food of both, viz. of the completely
undigested and the completely digested matter, we can justify both the
rival accounts of it; taking food in the sense of undigested matter, it
is the contrary of what is fed by it, taking it as digested it is like
what is fed by it. Consequently it is clear that in a certain sense we
may say that both parties are right, both wrong.
Since nothing except what is alive can be fed, what is fed is the
besouled body and just because it has soul in it. Hence food is essentially
related to what has soul in it. Food has a power which is other than the
power to increase the bulk of what is fed by it; so far forth as what has
soul in it is a quantum, food may increase its quantity, but it is only
so far as what has soul in it is a 'this-somewhat' or substance that food
acts as food; in that case it maintains the being of what is fed, and that
continues to be what it is so long as the process of nutrition continues.
Further, it is the agent in generation, i.e. not the generation of the
individual fed but the reproduction of another like it; the substance of
the individual fed is already in existence; the existence of no substance
is a self-generation but only a self-maintenance.
Hence the psychic power which we are now studying may be described
as that which tends to maintain whatever has this power in it of continuing
such as it was, and food helps it to do its work. That is why, if deprived
of food, it must cease to be.
The process of nutrition involves three factors, (a) what is fed,
(b) that wherewith it is fed, (c) what does the feeding; of these (c) is
the first soul, (a) the body which has that soul in it, (b) the food. But
since it is right to call things after the ends they realize, and the end
of this soul is to generate another being like that in which it is, the
first soul ought to be named the reproductive soul. The expression (b)
'wherewith it is fed' is ambiguous just as is the expression 'wherewith
the ship is steered'; that may mean either (i) the hand or (ii) the rudder,
i.e. either (i) what is moved and sets in movement, or (ii) what is merely
moved. We can apply this analogy here if we recall that all food must be
capable of being digested, and that what produces digestion is warmth;
that is why everything that has soul in it possesses
warmth.
We have now given an outline account of the nature of food; further
details must be given in the appropriate place.
Part 5
Having made these distinctions let us now speak of sensation in
the widest sense. Sensation depends, as we have said, on a process of movement
or affection from without, for it is held to be some sort of change of
quality. Now some thinkers assert that like is affected only by like; in
what sense this is possible and in what sense impossible, we have explained
in our general discussion of acting and being acted
upon.
Here arises a problem: why do we not perceive the senses themselves
as well as the external objects of sense, or why without the stimulation
of external objects do they not produce sensation, seeing that they contain
in themselves fire, earth, and all the other elements, which are the direct
or indirect objects is so of sense? It is clear that what is sensitive
is only potentially, not actually. The power of sense is parallel to what
is combustible, for that never ignites itself spontaneously, but requires
an agent which has the power of starting ignition; otherwise it could have
set itself on fire, and would not have needed actual fire to set it
ablaze.
In reply we must recall that we use the word 'perceive' in two
ways, for we say (a) that what has the power to hear or see, 'sees' or
'hears', even though it is at the moment asleep, and also (b) that what
is actually seeing or hearing, 'sees' or 'hears'. Hence 'sense' too must
have two meanings, sense potential, and sense actual. Similarly 'to be
a sentient' means either (a) to have a certain power or (b) to manifest
a certain activity. To begin with, for a time, let us speak as if there
were no difference between (i) being moved or affected, and (ii) being
active, for movement is a kind of activity-an imperfect kind, as has elsewhere
been explained. Everything that is acted upon or moved is acted upon by
an agent which is actually at work. Hence it is that in one sense, as has
already been stated, what acts and what is acted upon are like, in another
unlike, i.e. prior to and during the change the two factors are unlike,
after it like.
But we must now distinguish not only between what is potential
and what is actual but also different senses in which things can be said
to be potential or actual; up to now we have been speaking as if each of
these phrases had only one sense. We can speak of something as 'a knower'
either (a) as when we say that man is a knower, meaning that man falls
within the class of beings that know or have knowledge, or (b) as when
we are speaking of a man who possesses a knowledge of grammar; each of
these is so called as having in him a certain potentiality, but there is
a difference between their respective potentialities, the one (a) being
a potential knower, because his kind or matter is such and such, the other
(b), because he can in the absence of any external counteracting cause
realize his knowledge in actual knowing at will. This implies a third meaning
of 'a knower' (c), one who is already realizing his knowledge-he is a knower
in actuality and in the most proper sense is knowing, e.g. this A. Both
the former are potential knowers, who realize their respective potentialities,
the one (a) by change of quality, i.e. repeated transitions from one state
to its opposite under instruction, the other (b) by the transition from
the inactive possession of sense or grammar to their active exercise. The
two kinds of transition are distinct.
Also the expression 'to be acted upon' has more than one meaning;
it may mean either (a) the extinction of one of two contraries by the other,
or (b) the maintenance of what is potential by the agency of what is actual
and already like what is acted upon, with such likeness as is compatible
with one's being actual and the other potential. For what possesses knowledge
becomes an actual knower by a transition which is either not an alteration
of it at all (being in reality a development into its true self or actuality)
or at least an alteration in a quite different sense from the usual
meaning.
Hence it is wrong to speak of a wise man as being 'altered' when
he uses his wisdom, just as it would be absurd to speak of a builder as
being altered when he is using his skill in building a
house.
What in the case of knowing or understanding leads from potentiality
to actuality ought not to be called teaching but something else. That which
starting with the power to know learns or acquires knowledge through the
agency of one who actually knows and has the power of teaching either (a)
ought not to be said 'to be acted upon' at all or (b) we must recognize
two senses of alteration, viz. (i) the substitution of one quality for
another, the first being the contrary of the second, or (ii) the development
of an existent quality from potentiality in the direction of fixity or
nature.
In the case of what is to possess sense, the first transition is
due to the action of the male parent and takes place before birth so that
at birth the living thing is, in respect of sensation, at the stage which
corresponds to the possession of knowledge. Actual sensation corresponds
to the stage of the exercise of knowledge. But between the two cases compared
there is a difference; the objects that excite the sensory powers to activity,
the seen, the heard, &c., are outside. The ground of this difference is
that what actual sensation apprehends is individuals, while what knowledge
apprehends is universals, and these are in a sense within the soul. That
is why a man can exercise his knowledge when he wishes, but his sensation
does not depend upon himself a sensible object must be there. A similar
statement must be made about our knowledge of what is sensible-on the same
ground, viz. that the sensible objects are individual and
external.
A later more appropriate occasion may be found thoroughly to clear
up all this. At present it must be enough to recognize the distinctions
already drawn; a thing may be said to be potential in either of two senses,
(a) in the sense in which we might say of a boy that he may become a general
or (b) in the sense in which we might say the same of an adult, and there
are two corresponding senses of the term 'a potential sentient'. There
are no separate names for the two stages of potentiality; we have pointed
out that they are different and how they are different. We cannot help
using the incorrect terms 'being acted upon or altered' of the two transitions
involved. As we have said, has the power of sensation is potentially like
what the perceived object is actually; that is, while at the beginning
of the process of its being acted upon the two interacting factors are
dissimilar, at the end the one acted upon is assimilated to the other and
is identical in quality with it.
Part 6
In dealing with each of the senses we shall have first to speak
of the objects which are perceptible by each. The term 'object of sense'
covers three kinds of objects, two kinds of which are, in our language,
directly perceptible, while the remaining one is only incidentally perceptible.
Of the first two kinds one (a) consists of what is perceptible by a single
sense, the other (b) of what is perceptible by any and all of the senses.
I call by the name of special object of this or that sense that which cannot
be perceived by any other sense than that one and in respect of which no
error is possible; in this sense colour is the special object of sight,
sound of hearing, flavour of taste. Touch, indeed, discriminates more than
one set of different qualities. Each sense has one kind of object which
it discerns, and never errs in reporting that what is before it is colour
or sound (though it may err as to what it is that is coloured or where
that is, or what it is that is sounding or where that is.) Such objects
are what we propose to call the special objects of this or that
sense.
'Common sensibles' are movement, rest, number, figure, magnitude;
these are not peculiar to any one sense, but are common to all. There are
at any rate certain kinds of movement which are perceptible both by touch
and by sight.
We speak of an incidental object of sense where e.g. the white
object which we see is the son of Diares; here because 'being the son of
Diares' is incidental to the directly visible white patch we speak of the
son of Diares as being (incidentally) perceived or seen by us. Because
this is only incidentally an object of sense, it in no way as such affects
the senses. Of the two former kinds, both of which are in their own nature
perceptible by sense, the first kind-that of special objects of the several
senses-constitute the objects of sense in the strictest sense of the term
and it is to them that in the nature of things the structure of each several
sense is adapted.
Part 7
The object of sight is the visible, and what is visible is (a)
colour and (b) a certain kind of object which can be described in words
but which has no single name; what we mean by (b) will be abundantly clear
as we proceed. Whatever is visible is colour and colour is what lies upon
what is in its own nature visible; 'in its own nature' here means not that
visibility is involved in the definition of what thus underlies colour,
but that that substratum contains in itself the cause of visibility. Every
colour has in it the power to set in movement what is actually transparent;
that power constitutes its very nature. That is why it is not visible except
with the help of light; it is only in light that the colour of a thing
is seen. Hence our first task is to explain what light
is.
Now there clearly is something which is transparent, and by 'transparent'
I mean what is visible, and yet not visible in itself, but rather owing
its visibility to the colour of something else; of this character are air,
water, and many solid bodies. Neither air nor water is transparent because
it is air or water; they are transparent because each of them has contained
in it a certain substance which is the same in both and is also found in
the eternal body which constitutes the uppermost shell of the physical
Cosmos. Of this substance light is the activity-the activity of what is
transparent so far forth as it has in it the determinate power of becoming
transparent; where this power is present, there is also the potentiality
of the contrary, viz. darkness. Light is as it were the proper colour of
what is transparent, and exists whenever the potentially transparent is
excited to actuality by the influence of fire or something resembling 'the
uppermost body'; for fire too contains something which is one and the same
with the substance in question.
We have now explained what the transparent is and what light is;
light is neither fire nor any kind whatsoever of body nor an efflux from
any kind of body (if it were, it would again itself be a kind of body)-it
is the presence of fire or something resembling fire in what is transparent.
It is certainly not a body, for two bodies cannot be present in the same
place. The opposite of light is darkness; darkness is the absence from
what is transparent of the corresponding positive state above characterized;
clearly therefore, light is just the presence of that.
Empedocles (and with him all others who used the same forms of
expression) was wrong in speaking of light as 'travelling' or being at
a given moment between the earth and its envelope, its movement being unobservable
by us; that view is contrary both to the clear evidence of argument and
to the observed facts; if the distance traversed were short, the movement
might have been unobservable, but where the distance is from extreme East
to extreme West, the draught upon our powers of belief is too
great.
What is capable of taking on colour is what in itself is colourless,
as what can take on sound is what is soundless; what is colourless includes
(a) what is transparent and (b) what is invisible or scarcely visible,
i.e. what is 'dark'. The latter (b) is the same as what is transparent,
when it is potentially, not of course when it is actually transparent;
it is the same substance which is now darkness, now
light.
Not everything that is visible depends upon light for its visibility.
This is only true of the 'proper' colour of things. Some objects of sight
which in light are invisible, in darkness stimulate the sense; that is,
things that appear fiery or shining. This class of objects has no simple
common name, but instances of it are fungi, flesh, heads, scales, and eyes
of fish. In none of these is what is seen their own proper' colour. Why
we see these at all is another question. At present what is obvious is
that what is seen in light is always colour. That is why without the help
of light colour remains invisible. Its being colour at all means precisely
its having in it the power to set in movement what is already actually
transparent, and, as we have seen, the actuality of what is transparent
is just light.
The following experiment makes the necessity of a medium clear.
If what has colour is placed in immediate contact with the eye, it cannot
be seen. Colour sets in movement not the sense organ but what is transparent,
e.g. the air, and that, extending continuously from the object to the organ,
sets the latter in movement. Democritus misrepresents the facts when he
expresses the opinion that if the interspace were empty one could distinctly
see an ant on the vault of the sky; that is an impossibility. Seeing is
due to an affection or change of what has the perceptive faculty, and it
cannot be affected by the seen colour itself; it remains that it must be
affected by what comes between. Hence it is indispensable that there be
something in between-if there were nothing, so far from seeing with greater
distinctness, we should see nothing at all.
We have now explained the cause why colour cannot be seen otherwise
than in light. Fire on the other hand is seen both in darkness and in light;
this double possibility follows necessarily from our theory, for it is
just fire that makes what is potentially transparent actually
transparent.
The same account holds also of sound and smell; if the object of
either of these senses is in immediate contact with the organ no sensation
is produced. In both cases the object sets in movement only what lies between,
and this in turn sets the organ in movement: if what sounds or smells is
brought into immediate contact with the organ, no sensation will be produced.
The same, in spite of all appearances, applies also to touch and taste;
why there is this apparent difference will be clear later. What comes between
in the case of sounds is air; the corresponding medium in the case of smell
has no name. But, corresponding to what is transparent in the case of colour,
there is a quality found both in air and water, which serves as a medium
for what has smell-I say 'in water' because animals that live in water
as well as those that live on land seem to possess the sense of smell,
and 'in air' because man and all other land animals that breathe, perceive
smells only when they breathe air in. The explanation of this too will
be given later.
Part 8
Now let us, to begin with, make certain distinctions about sound
and hearing.
Sound may mean either of two things (a) actual, and (b) potential,
sound. There are certain things which, as we say, 'have no sound', e.g.
sponges or wool, others which have, e.g. bronze and in general all things
which are smooth and solid-the latter are said to have a sound because
they can make a sound, i.e. can generate actual sound between themselves
and the organ of hearing.
Actual sound requires for its occurrence (i, ii) two such bodies
and (iii) a space between them; for it is generated by an impact. Hence
it is impossible for one body only to generate a sound-there must be a
body impinging and a body impinged upon; what sounds does so by striking
against something else, and this is impossible without a movement from
place to place.
As we have said, not all bodies can by impact on one another produce
sound; impact on wool makes no sound, while the impact on bronze or any
body which is smooth and hollow does. Bronze gives out a sound when struck
because it is smooth; bodies which are hollow owing to reflection repeat
the original impact over and over again, the body originally set in movement
being unable to escape from the concavity.
Further, we must remark that sound is heard both in air and in
water, though less distinctly in the latter. Yet neither air nor water
is the principal cause of sound. What is required for the production of
sound is an impact of two solids against one another and against the air.
The latter condition is satisfied when the air impinged upon does not retreat
before the blow, i.e. is not dissipated by it.
That is why it must be struck with a sudden sharp blow, if it is
to sound-the movement of the whip must outrun the dispersion of the air,
just as one might get in a stroke at a heap or whirl of sand as it was
traveling rapidly past.
An echo occurs, when, a mass of air having been unified, bounded,
and prevented from dissipation by the containing walls of a vessel, the
air originally struck by the impinging body and set in movement by it rebounds
from this mass of air like a ball from a wall. It is probable that in all
generation of sound echo takes place, though it is frequently only indistinctly
heard. What happens here must be analogous to what happens in the case
of light; light is always reflected-otherwise it would not be diffused
and outside what was directly illuminated by the sun there would be blank
darkness; but this reflected light is not always strong enough, as it is
when it is reflected from water, bronze, and other smooth bodies, to cast
a shadow, which is the distinguishing mark by which we recognize
light.
It is rightly said that an empty space plays the chief part in
the production of hearing, for what people mean by 'the vacuum' is the
air, which is what causes hearing, when that air is set in movement as
one continuous mass; but owing to its friability it emits no sound, being
dissipated by impinging upon any surface which is not smooth. When the
surface on which it impinges is quite smooth, what is produced by the original
impact is a united mass, a result due to the smoothness of the surface
with which the air is in contact at the other end.
What has the power of producing sound is what has the power of
setting in movement a single mass of air which is continuous from the impinging
body up to the organ of hearing. The organ of hearing is physically united
with air, and because it is in air, the air inside is moved concurrently
with the air outside. Hence animals do not hear with all parts of their
bodies, nor do all parts admit of the entrance of air; for even the part
which can be moved and can |
