Part I (Prima Pars) Part 119 (2/2)

Reply Obj. 1: Not every accident has in itself a power of immutation but only qualities of the third species, which are the principles of alteration: therefore only suchlike qualities are the objects of the senses; because ”the senses are affected by the same things whereby inanimate bodies are affected,” as stated in Phys. vii, 2.

Reply Obj. 2: Size, shape, and the like, which are called ”common sensibles,” are midway between ”accidental sensibles” and ”proper sensibles,” which are the objects of the senses. For the proper sensibles first, and of their very nature, affect the senses; since they are qualities that cause alteration. But the common sensibles are all reducible to quant.i.ty. As to size and number, it is clear that they are species of quant.i.ty. Shape is a quality about quant.i.ty, since the notion of shape consists of fixing the bounds of magnitude.

Movement and rest are sensed according as the subject is affected in one or more ways in the magnitude of the subject or of its local distance, as in the movement of growth or of locomotion, or again, according as it is affected in some sensible qualities, as in the movement of alteration; and thus to sense movement and rest is, in a way, to sense one thing and many. Now quant.i.ty is the proximate subject of the qualities that cause alteration, as surface is of color. Therefore the common sensibles do not move the senses first and of their own nature, but by reason of the sensible quality; as the surface by reason of color. Yet they are not accidental sensibles, for they produce a certain variety in the immutation of the senses. For sense is immuted differently by a large and by a small surface: since whiteness itself is said to be great or small, and therefore it is divided according to its proper subject.

Reply Obj. 3: As the Philosopher seems to say (De Anima ii, 11), the sense of touch is generically one, but is divided into several specific senses, and for this reason it extends to various contrarieties; which senses, however, are not separate from one another in their organ, but are spread throughout the whole body, so that their distinction is not evident. But taste, which perceives the sweet and the bitter, accompanies touch in the tongue, but not in the whole body; so it is easily distinguished from touch. We might also say that all those contrarieties agree, each in some proximate genus, and all in a common genus, which is the common and formal object of touch. Such common genus is, however, unnamed, just as the proximate genus of hot and cold is unnamed.

Reply Obj. 4: The sense of taste, according to a saying of the Philosopher (De Anima ii, 9), is a kind of touch existing in the tongue only. It is not distinct from touch in general, but only from the species of touch distributed in the body. But if touch is one sense only, on account of the common formality of its object: we must say that taste is distinguished from touch by reason of a different formality of immutation. For touch involves a natural, and not only a spiritual, immutation in its organ, by reason of the quality which is its proper object. But the organ of taste is not necessarily immuted by a natural immutation by reason of the quality which is its proper object, so that the tongue itself becomes sweet and bitter: but by reason of a quality which is a preamble to, and on which is based, the flavor, which quality is moisture, the object of touch.

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FOURTH ARTICLE [I, Q. 78, Art. 4]

Whether the Interior Senses Are Suitably Distinguished?

Objection 1: It would seem that the interior senses are not suitably distinguished. For the common is not divided against the proper.

Therefore the common sense should not be numbered among the interior sensitive powers, in addition to the proper exterior senses.

Obj. 2: Further, there is no need to a.s.sign an interior power of apprehension when the proper and exterior sense suffices. But the proper and exterior senses suffice for us to judge of sensible things; for each sense judges of its proper object. In like manner they seem to suffice for the perception of their own actions; for since the action of the sense is, in a way, between the power and its object, it seems that sight must be much more able to perceive its own vision, as being nearer to it, than the color; and in like manner with the other senses. Therefore for this there is no need to a.s.sign an interior power, called the common sense.

Obj. 3: Further, according to the Philosopher (De Memor. et Remin.

i), the imagination and the memory are pa.s.sions of the ”first sensitive.” But pa.s.sion is not divided against its subject. Therefore memory and imagination should not be a.s.signed as powers distinct from the senses.

Obj. 4: Further, the intellect depends on the senses less than any power of the sensitive part. But the intellect knows nothing but what it receives from the senses; whence we read (Poster. i, 8), that ”those who lack one sense lack one kind of knowledge.” Therefore much less should we a.s.sign to the sensitive part a power, which they call the ”estimative” power, for the perception of intentions which the sense does not perceive.

Obj. 5: Further, the action of the cogitative power, which consists in comparing, adding and dividing, and the action of the reminiscence, which consists in the use of a kind of syllogism for the sake of inquiry, is not less distant from the actions of the estimative and memorative powers, than the action of the estimative is from the action of the imagination. Therefore either we must add the cognitive and reminiscitive to the estimative and memorative powers, or the estimative and memorative powers should not be made distinct from the imagination.

Obj. 6: Further, Augustine (Gen. ad lit. xii, 6, 7, 24) describes three kinds of vision; namely, corporeal, which is the action of the sense; spiritual, which is an action of the imagination or phantasy; and intellectual, which is an action of the intellect. Therefore there is no interior power between the sense and intellect, besides the imagination.

_On the contrary,_ Avicenna (De Anima iv, 1) a.s.signs five interior sensitive powers; namely, ”common sense, phantasy, imagination, and the estimative and memorative powers.”

_I answer that,_ As nature does not fail in necessary things, there must needs be as many actions of the sensitive soul as may suffice for the life of a perfect animal. If any of these actions cannot be reduced to the same one principle, they must be a.s.signed to diverse powers; since a power of the soul is nothing else than the proximate principle of the soul's operation.

Now we must observe that for the life of a perfect animal, the animal should apprehend a thing not only at the actual time of sensation, but also when it is absent. Otherwise, since animal motion and action follow apprehension, an animal would not be moved to seek something absent: the contrary of which we may observe specially in perfect animals, which are moved by progression, for they are moved towards something apprehended and absent. Therefore an animal through the sensitive soul must not only receive the species of sensible things, when it is actually affected by them, but it must also retain and preserve them. Now to receive and retain are, in corporeal things, reduced to diverse principles; for moist things are apt to receive, but retain with difficulty, while it is the reverse with dry things.

Wherefore, since the sensitive power is the act of a corporeal organ, it follows that the power which receives the species of sensible things must be distinct from the power which preserves them.

Again we must observe that if an animal were moved by pleasing and disagreeable things only as affecting the sense, there would be no need to suppose that an animal has a power besides the apprehension of those forms which the senses perceive, and in which the animal takes pleasure, or from which it shrinks with horror. But the animal needs to seek or to avoid certain things, not only because they are pleasing or otherwise to the senses, but also on account of other advantages and uses, or disadvantages: just as the sheep runs away when it sees a wolf, not on account of its color or shape, but as a natural enemy: and again a bird gathers together straws, not because they are pleasant to the sense, but because they are useful for building its nest. Animals, therefore, need to perceive such intentions, which the exterior sense does not perceive. And some distinct principle is necessary for this; since the perception of sensible forms comes by an immutation caused by the sensible, which is not the case with the perception of those intentions.

Thus, therefore, for the reception of sensible forms, the ”proper sense” and the _common sense_ are appointed, and of their distinction we shall speak farther on (ad 1, 2). But for the retention and preservation of these forms, the ”phantasy” or ”imagination” is appointed; which are the same, for phantasy or imagination is as it were a storehouse of forms received through the senses. Furthermore, for the apprehension of intentions which are not received through the senses, the ”estimative” power is appointed: and for the preservation thereof, the ”memorative” power, which is a storehouse of such-like intentions. A sign of which we have in the fact that the principle of memory in animals is found in some such intention, for instance, that something is harmful or otherwise. And the very formality of the past, which memory observes, is to be reckoned among these intentions.

Now, we must observe that as to sensible forms there is no difference between man and other animals; for they are similarly immuted by the extrinsic sensible. But there is a difference as to the above intentions: for other animals perceive these intentions only by some natural instinct, while man perceives them by means of coalition of ideas. Therefore the power by which in other animals is called the natural estimative, in man is called the ”cogitative,” which by some sort of collation discovers these intentions. Wherefore it is also called the ”particular reason,” to which medical men a.s.sign a certain particular organ, namely, the middle part of the head: for it compares individual intentions, just as the intellectual reason compares universal intentions. As to the memorative power, man has not only memory, as other animals have in the sudden recollection of the past; but also ”reminiscence” by syllogistically, as it were, seeking for a recollection of the past by the application of individual intentions.

Avicenna, however, a.s.signs between the estimative and the imaginative, a fifth power, which combines and divides imaginary forms: as when from the imaginary form of gold, and imaginary form of a mountain, we compose the one form of a golden mountain, which we have never seen.

But this operation is not to be found in animals other than man, in whom the imaginative power suffices thereto. To man also does Averroes attribute this action in his book _De sensu et sensibilibus_ (viii).

So there is no need to a.s.sign more than four interior powers of the sensitive part--namely, the common sense, the imagination, and the estimative and memorative powers.

Reply Obj. 1: The interior sense is called ”common” not by predication, as if it were a genus; but as the common root and principle of the exterior senses.

Reply Obj. 2: The proper sense judges of the proper sensible by discerning it from other things which come under the same sense; for instance, by discerning white from black or green. But neither sight nor taste can discern white from sweet: because what discerns between two things must know both. Wherefore the discerning judgment must be a.s.signed to the common sense; to which, as to a common term, all apprehensions of the senses must be referred: and by which, again, all the intentions of the senses are perceived; as when someone sees that he sees. For this cannot be done by the proper sense, which only knows the form of the sensible by which it is immuted, in which immutation the action of sight is completed, and from immutation follows another in the common sense which perceives the act of vision.

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