De Anima

Cognition is in our eyes a thing of beauty and worth¹, and this is true of one cognition more than another, either because it is exact or because it relates to more important and remarkable objects. On both these grounds we may with good reason claim a high place for the enquiry concerning the soul. It would seem, too, that an acquaintance with the subject contributes greatly to the whole domain of truth and, more particularly, to the study of nature, the soul being virtually the principle of all animal life. Our aim is to discover and ascertain the nature and: essence of soul and, in the next place, all the accidents belonging to it; of which some are thought to be attributes peculiar to the soul itself, while others, it is held, belong to the animal also, but owe their existence to the soul. But everywhere and in every way it is extremely difficult to arrive at any trustworthy conclusion on the subject. It is the same here as in many other enquiries. What we have to investigate is the essential nature of things and the What. It might therefore be thought that there is a single procedure applicable to all the objects whose essential nature we wish to discover, as demonstration is applicable to the properties which go along with them: in that case we should have to enquire what this procedure is. If, however, there is no single procedure common to all sciences for defining the What, our task becomes still more difficult, as it will then be necessary to settle in each particular case the method to be pursued. Further, even if it be evident that it consists in demonstration of some sort or division or some other procedure, there

is still room for much perplexity and error, when we ask from what premisses our enquiry should start, for there are different premisses for different sciences; for the science of numbers, for example, and plane geometry.

The first thing necessary is no doubt to determine under which of the summa genera soul comes and what it is; I mean, whether it is a particular thing, i.e. substance, or is quality or is quantity, or falls under any other of the categories already determined. We must further ask whether it is amongst things potentially existent or is rather a sort of actuality, the distinction being all-important. Again, we must consider whether it is divisible or indivisible; whether, again, all and every soul is homogeneous or not; and, if not, whether the difference between the various souls is a difference of species or a difference of genus: for at present discussions and investigations about soul would appear to be restricted to the human soul. We must take care not to overlook the question whether there is a single definition of soul answering to a single definition of animal; or whether there is a different definition for each separate soul, as for horse and dog, man and god: animal, as the universal, being regarded either as non-existent or, if existent, as logically posterior. This is a question which might equally be raised in regard to any other common predicate. Further, on the assumption that there are not several souls, but merely several different parts in the same soul, it is a question whether we should begin by investigating soul as a whole or its several parts. And here again it is difficult to determine which of these parts are really distinct from one another and whether the several parts, or their functions, should be investigated first. Thus, e.g. should the process of thinking come first or the mind that thinks, the process of sensation or the sensitive faculty? And so everywhere else. But, if the functions should come first, again will arise the question whether we should first investigate the correlative objects. Shall we take, eg., the sensible object before the faculty of sense and the intelligible object before the intellect ?

It would seem that not only is the knowledge of a thing's essential nature useful for discovering the causes of its attributes, as, ¢.g., in mathematics the knowledge of what

' is meant by the terms straight or curved, line or surface, aids us in discovering to how many right angles the angles of a triangle are equal: but also, conversely, a knowledge of the attributes is a considerable aid to the knowledge of what a thing is.

For when we are able to give an account of all, or at any rate most, of the attributes as they are presented to us, then we shall be in a position to define most exactly the essential nature of the thing. In fact, the starting point of every demonstration is a definition of what something is. Hence the definitions which lead to no information about attributes and do not facilitate even conjecture respecting them have clearly been framed for dialectic and are void of content, one and all.

A further difficulty arises as to whether all attributes of the soul are also shared by that which contains the soul or whether any of them are peculiar to the soul itself: a question which it is indispensable, and yet by no means easy, to decide. It would appear that in most cases soul neither acts nor is acted upon apart from the body: as, e.g., in anger, confidence, desire and sensation in general. Thought, if anything, would seem to be peculiar to the soul. Yet, if thought is a sort of imagination, or not independent of imagination, it will follow that even thought cannot be independent of the body. If, then, there be any of the functions or affections of the soul peculiar to it, it will be possible for the soul to be separated from the body: if, on the other hand, there is nothing of the sort peculiar to it, the soul will not be capable of separate existence. As with the straight line, so with it. The line, qua straight, has many properties; for instance, it touches the brazen sphere at a point; but it by no means follows that it will so touch it if separated. In fact it is inseparable, since it is always conjoined with body of some sort. So, too, the attributes of the soul appear to be all conjoined with body: such attributes, viz., as anger, mildness, fear, pity, courage; also joy, love and hate; all of which are attended by some particular affection of the body. This indeed is shown by the fact that sometimes violent and palpable incentives occur without producing in us exasperation or fear, while at other times we are moved by slight and scarcely perceptible causes, when the blood is up and the bodily condition that of anger. Still more is this evident from the fact that sometimes even without the occurrence of anything terrible men exhibit all the symptoms of terror. If this be so, the attributes are evidently forms or notions realised in matter.

Hence they must be defined accordingly: anger, for instance, as a certain movement in a body of a given kind, or some part or faculty of it, produced by such and such a cause and for such and such an end. These facts at once bring the investigation of soul, whether in its entirety or in the particular aspect described, within the province of the natural philosopher. But every such attribute would be differently defined by the physicist and the dialectician or philosopher. Anger, for instance, would be defined by the dialectician as desire for retaliation or the like, by the physicist as a ferment of the blood or heat² which is about the heart: the one of them gives the matter, the other the form or notion. For the notion is the form of the thing, but this notion, if it is to be, must be realised in matter of a particular kind; just as in the case of a house. The notion or definition of a house would be as follows: a shelter to protect us from harm by wind or rain or scorching heat; while another will describe it as stones, bricks and timber; and again another as the form realised in these materials and subserving given ends. Which then of these is the true physicist? Is it he who confines himself to the matter, while ignoring the form? Or he who treats of the form exclusively? I answer, it is rather he who in his definition takes account of both. What then of each of the other two? Or shall we rather say that there is no one who deals with properties which are not separable nor yet treated as separable, but the physicist deals with all the active properties or passive affections belonging to body of a given sort and the corresponding matter? All attributes not regarded as so belonging he leaves to someone else: who in certain cases is an expert, a carpenter, for instance, or a physician. The attributes which, though inseparable, are not regarded as properties of body of a given sort, but are reached by abstraction, fall within the province of the mathematician: while attributes which are regarded as having separate existence fall to the first philosopher or metaphysician. But to return to the point of digression. We were saying that the attributes of the soul are as such,—I mean, as anger and fear, inseparable from the physical matter of the animals to which they belong, and not, like line and surface, separable in thought.