by Aristotle
All movement involves three factors, (1) that which originates the movement, (2) that by means of which it originates it, and (3) that which is moved. The expression ‘that which originates the movement’ is ambiguous: it may mean either something which itself is unmoved or that which at once moves and is moved. Here [15] that which moves without itself being moved is the realizable good, that which at once moves and is moved is the faculty of appetite (for that which is moved is moved insofar as it desires, and appetite in the sense of actual appetite is a kind of movement), while that which is in motion is the animal. The instrument which appetite employs to produce movement is bodily: hence the examination of it falls within the province of the functions common to body and soul. To state the matter [20] summarily at present, that which is the instrument in the production of movement is to be found where a beginning and an end coincide as e.g. in a ball and socket joint; for there the convex and the concave sides are respectively an end and a beginning (that is why while the one remains at rest, the other is moved): they are separate in definition but not separable spatially. For everything is moved by pushing and [25] pulling. Hence just as in the case of a wheel, so here there must be a point which remains at rest, and from that point the movement must originate.
To sum up, then, and repeat what I have said, inasmuch as an animal is capable of appetite it is capable of self-movement; it is not capable of appetite without possessing imagination; and all imagination is either calculative or sensitive. In the latter all animals partake. [30]
11 · We must consider also in the case of imperfect animals, sc. those which have no sense but touch, what it is that in them originates movement. Can they have [434a1] imagination or not? or desire? Clearly they have feelings of pleasure and pain, and if they have these they must have desire. But how can they have imagination? Must not we say that, as their movements are indefinite, they have imagination and [5] desire, but indefinitely?
Sensitive imagination, as we have said, is found in all animals, deliberative imagination only in those that are calculative: for whether this or that shall be enacted is already a task requiring calculation; and there must be a single standard to measure by, for that is pursued which is greater. It follows that what acts in this way must be able to make a unity out of several images.
[10] This is the reason why imagination is held not to involve opinion, in that it does not involve opinion based on inference, though opinion involves imagination.42 Hence appetite contains no deliberative element. Sometimes it overpowers wish and sets it in movement; at times wish acts thus upon appetite, like a ball,43 appetite overcoming appetite, i.e. in the condition of moral weakness (though by nature the [15] higher faculty is always more authoritative and gives rise to movement). Thus three modes of movement are possible.
The faculty of knowing is never moved but remains at rest. Since the one premiss or judgement is universal and the other deals with the particular (for the first tells us that such and such a kind of man should do such and such a kind of act, and the second that this is an act of the kind meant, and I a person of the type intended), it is the latter opinion that really originates movement, not the universal; [20] or rather it is both, but the one does so while it remains in a state more like rest, while the other partakes in movement.
12 · The nutritive soul then must be possessed by everything that is alive and has a soul, from its birth to its death. For what has been born must grow, reach [25] maturity, and decay—all of which are impossible without nutrition. Therefore the nutritive faculty must be found in everything that grows and decays.
But sensation need not be found in all things that live. For it is impossible for touch to belong either to those whose body is uncompounded or to those which are incapable of taking in the forms without their matter.
[30] But animals must be endowed with sensation, since Nature does nothing in vain. For all things that exist by Nature are means to an end, or will be concomitants of means to an end. Every body capable of forward movement would, [434b1] if unendowed with sensation, perish and fail to reach its end, which is the aim of Nature; for how could it obtain nutriment? Stationary living things, it is true, have as their nutriment that from which they have arisen; but it is not possible that a body which is not stationary but produced by generation should have a soul and a discerning mind without also having sensation. (Nor yet even if it were not [5] produced by generation.) Why should it not have sensation? It would have to be better either for the soul or for the body; but in fact it is neither—for the absence of sensation will not enable the one to think better or the other to exist better. Therefore no body which is not stationary has soul without sensation.
But if a body has sensation, it must be either simple or compound. And simple [10] it cannot be; for then it could not have touch, which is indispensable. This is clear from what follows. An animal is a body with soul in it: every body is tangible, i.e. perceptible by touch; hence necessarily, if an animal is to survive, its body must have tactual sensation. All the other senses, e.g. smell, sight, hearing, apprehend [15] through media; but where there is immediate contact the animal, if it has no sensation, will be unable to avoid some things and take others, and so will find it impossible to survive. That is why taste also is a sort of touch; it is relative to nutriment, which is just tangible body; whereas sound, colour, and odour are not [20] nutritious, and further neither grow nor decay. Hence it is that taste also must be a sort of touch, because it is the sense for what is tangible and nutritious.
Both these senses, then, are indispensable to the animal, and it is clear that without touch it is impossible for an animal to be. All the other senses subserve well-being and for that very reason belong not to any and every kind of animal, but only to some, e.g. those capable of forward movement must have them; for, if they [25] are to survive, they must perceive not only by immediate contact but also at a distance from the object. This will be possible if they can perceive through a medium, the medium being affected and moved by the perceptible object, and the animal by the medium. Just as that which produces local movement causes a change extending to a certain point, and that which gave an impulse causes another [30] to produce a new impulse so that the movement traverses a medium—the first mover impelling without being impelled, the last moved being impelled without impelling, while the medium (or media, for there are many) is both—so is it also in [435a1] the case of alteration, except that the agent produces it without the patient’s changing its place. Thus if an object is dipped into wax, the movement goes on until submersion has taken place, and in stone it goes no distance at all, while in water the disturbance goes far beyond the object dipped: in air the disturbance is propagated farthest of all, the air acting and being acted upon, so long as it maintains an unbroken unity. That is why in the case of reflection it is better, instead of saying [5] that the sight issues from the eye and is reflected, to say that the air, so long as it remains one, is affected by the shape and colour. On a smooth surface the air possesses unity; hence it is that it in turn sets the sight in motion, just as if the impression on the wax were transmitted as far as the wax extends. [10]
13 · It is clear that the body of an animal cannot be simple, i.e. consist of one element such as fire or air. For without touch it is impossible to have any other sense; for every body that has soul in it must, as we have said, be capable of touch. All the other elements with the exception of earth can constitute organs of sense, [15] but all of them bring about perception only through something else, viz. through the media. Touch takes place by direct contact with its objects, whence also its name. All the other organs of sense, no doubt, perceive by contact, only the contact is mediate: touch alone perceives by immediate contact. Consequently no animal body [20] can consist of these other elements.
Nor can it consist solely of earth. For touch is as it were a mean between all tangible qualities, and its organ is capable of receiving not only all the specific qualities which characterize earth, but also the hot a
nd the cold and all other tangible qualities whatsoever. That is why we have no sensation by means of bones, [435b1] hair, &c., because they consist of earth. So too plants, because they consist of earth, have no sensation. Without touch there can be no other sense, and the organ of touch cannot consist of earth or of any other single element.
It is evident, therefore, that the loss of this one sense alone must bring about [5] the death of an animal. For as on the one hand nothing which is not an animal can have this sense, so on the other it is the only one which is indispensably necessary to what is an animal. This explains, further, why excesses of the other sensible objects, i.e. excess of colour, sound, and smell, destroys not the animal but only the organs of [10] the sense (except incidentally, as when the sound is accompanied by an impact or shock, or where through the objects of sight or of smell certain other things are set in motion, which destroy by contact—flavour also destroys only in so far as it is at the same time capable of contact), whereas excess in tangible qualities, e.g. heat, cold, [15] or hardness, destroys the animal itself. As in the case of every sensible quality excess destroys the organ, so here what is tangible destroys touch, which is the essential mark of being an animal; for it has been shown that without touch it is impossible for an animal to be. That is why excess in intensity of tangible qualities destroys not merely the organ, but the animal itself, because this is the only sense which it must have.
[20] All the other senses are necessary to animals, as we have said, not for their being, but for their well-being. Such, e.g., is sight, which, since it lives in air or water, or generally in what is transparent, it must have in order to see, and taste because of what is pleasant or painful to it, in order that it may perceive these qualities in its nutriment and so may desire to be set in motion, and hearing that it [25] may have communication made to it, and a tongue that it may communicate with its fellows.44
**TEXT: W. D. Ross, OCT, Oxford, 1956
1Iliad XXIII 698.
2Frag. 109 Diels-Kranz.
335Aff.
4See Physics VIII 5.
5Omitting νόησις.
6Retaining μή, with the MSS.
7Reading δέ for δή.
8Frag. 96 Diels-Kranz.
9Ross follows Torstrik in excising the words ‘locomotion or’.
10Omitting oὐ.
11Omitting ἤ with the MSS.
12Ross excises ‘bodies or’.
13See Gen Corr I 7.
14Retaining λέγoμεν.
15Retaining αἴσθησιν: Ross prints ἀριθμητικήν, ‘arithmetic’.
16Retaining τις.
17Retaining ἔμψυχoν.
18See Gen Corr II 2–3.
19Retaining τὸ ꜔ ρῶν.
20Retaining τὸ ꜔ ρῶν.
21Ross excises ‘and the being acted upon’.
22Ross, following Dittenberger, excises the sentence ‘or, to touch, … chilled’.
23Reading τίνι for τινί.
24Ross adds: ‘and indivisible’.
25Ross excises ‘two separate objects’.
26Reading ʶνί, ʶνἱ.
27Frag. 106 Diels-Kranz.
28Frag. 108 Diels-Kranz.
29Odyssey XVIII 136.
30Retaining νόησις.
31Retaining τότε ἤ.
32Ross, following Biehl, excises ‘Further . . . reason’, as a doublet of lines 19–22.
33Retaining δὲ α꜑ τόν.
34Retaining δεῖ.
35Frag. 57 Diels-Kranz.
36Ross adds: ‘and white’.
37Ross, following Bywater, places the bracketed sentence after ‘spatial’ in line 20.
38Omitting τῶν αἰτίων.
39Retaining ἐν πράξει.
40Reading, with most MSS, oὐ κεχωρισμένως, ᾗ δὲ κoῖλoν εἴ τις.
41Retaining ἤ.
42Ross, following Bywater, excises the last clause.
43Retaining the MSS text: κινεῖ τὴν βoύλησιν, ὅτε δ’ ἐκείνη ταύτην ὥσπερ σφαίρα.
44Ross, following Torstrik, excises the last clause.
SENSE AND SENSIBILIA**
J. I. Beare
1 · Having now considered the soul, by itself, and its several faculties, we [436a1] must next make a survey of animals and all living things, in order to ascertain what functions are peculiar, and what functions are common, to them. What has been already determined respecting the soul must be assumed throughout. The remaining [5] parts of our subject must be now dealt with, and we may begin with those that come first.
The most important attributes of animals, whether common to all or peculiar to some, are, manifestly, attributes of soul and body in conjunction, e.g., sensation, memory, passion, appetite and desire in general, and, in addition, pleasure and pain. For these may, in fact, be said to belong to all animals. But there are, besides [10] these, certain other attributes, of which some are common to all living things, while others are peculiar to certain species of animals. The most important of these may be summed up in four pairs, viz. waking and sleeping, youth and old age, inhalation [15] and exhalation, life and death. We must examine these, determining their respective natures, and the causes of their occurrence.
But it behoves the natural scientist to obtain also a clear view of the first principles of health and disease, inasmuch as neither health nor disease can exist in lifeless things. Indeed we may say of most physical inquirers, and of those physicians who study their art more philosophically, that while the former complete [20] their works with a disquisition on medicine, the latter start from a consideration of nature. [436b1]
That all the attributes above enumerated belong to soul and body in conjunction, is obvious; for they all either imply sensation as a concomitant, or have it as their medium. Some are either affections or states of sensation, others, means of defending and safe-guarding it, while others, again, involve its destruction or [5] privation. Now it is clear, alike by reasoning and without reasoning, that sensation is generated in the soul through the medium of the body.
We have already, in our treatise On the Soul, explained the nature of sensation [10] and perceiving, and the reason why this affection belongs to animals. Sensation must, indeed, be attributed to all animals as such, for by its presence or absence we distinguish between what is and what is not an animal.
But coming now to the special senses severally, we may say that touch and taste necessarily appertain to all animals, touch, for the reason given in On the Soul, [15] and taste, because of nutrition. It is by taste that one distinguishes in food the pleasant from the unpleasant, so as to flee from the latter and pursue the former; and savour in general is an affection of the nutritive part.
The senses which operate through external media, viz. smelling, hearing, seeing, are found in all animals which possess the faculty of locomotion. To all that [20] possess them they are a means of preservation in order that, guided by antecedent perception, they may both pursue their food, and shun things that are bad or [437a1] destructive. But in animals which have also intelligence they serve for the attainment of a higher perfection. They bring in tidings of many distinctive qualities of things, from which knowledge of things both speculative and practical is generated in the soul.
Of the two last mentioned, seeing, regarded as a supply for the primary wants [5] of life is in its own right the superior sense; but for developing thought hearing incidentally takes the precedence. The faculty of seeing, thanks to the fact that all bodies are coloured, brings tidings of multitudes of distinctive qualities of all sorts; whence it is through this sense especially that we perceive the common sensibles, viz. figure, magnitude, motion, number; while hearing announces only the distinctive [10] qualities of sound, and, to some few animals, those also of voice. Incidentally, however, it is hearing that contributes most to the growth of intelligence. For rational discourse is a cause of instruction in virtue o
f its being audible, which it is, not in its own right, but incidentally; since it is composed of words, and each word is [15] a symbol. Accordingly, of persons destitute from birth of either sense, the blind are more intelligent than the deaf and dumb.
2 · Of the distinctive powers of each of the faculties of sense enough has been said already.
But as to the nature of the sensory organs, or parts of the body in which each of [20] the senses is naturally implanted, some inquire into them with reference to the elements of bodies. Not, however, finding it easy to coordinate five senses with four elements, they are at a loss respecting the fifth sense. They all hold the organ of sight to consist of fire, being prompted to this view by a certain affection of whose true cause they are ignorant. This is that, when the eye is pressed and moved, fire [25] appears to flash from it. This naturally takes place in darkness, or when the eyelids are closed—for then, too, darkness is produced.
This raises another puzzle; for, unless a man can perceive1 and see without being aware of it, the eye must see itself. But then why does the above affection not occur also when the eye is at rest? The true explanation of this affection, which will [30] contain the answer to our question, and account for the current notion that the eye consists of fire, must be determined in the following way:—
Things which are smooth have the natural property of shining in darkness, without, however, producing light. Now, the part of the eye called the black, i.e. its central part, is smooth. The phenomenon of the flash occurs only when the eye is [437b1] moved, because one object then becomes as it were two. The rapidity of the movement has the effect of making that which sees and that which is seen seem different from one another. Hence the phenomenon does not occur unless the motion is rapid and takes place in darkness. For it is in the dark that that which is [5] smooth, e.g. the heads of certain fishes, and the sepia of the cuttle-fish, naturally shines, and, when the movement of the eye is slow, it is impossible that that which sees and that which is seen should appear to be simultaneously two and one. The eye sees itself in the above phenomenon as it does so in reflexion. [10]