LECTIO FIVE

             § 279. After defining the soul in general Aristotle comes to treat of its 'parts'. Now the soul has no parts except in the sense that its potentialities are parts of it; in that one subject, being in potency to many activities, its power with respect to each in particular can be called a part of it. To treat of its parts then is to treat of its various potencies. This he does here in two main sections: the first treats of the soul's powers in general and their distinction from one another; the second, at 'Hence we must speak first', takes them one by one. The former subdivides into (a) a division of the powers of the soul; and (b) at 'So we must enquire . . .', a discussion of what has to be proved about them, and how and in what order. The division itself of the powers (at 'It is therefore clear') necessitates showing how the soul as a whole is related to its parts; but before we come to this, the powers enumerated have to be related to each other, which he does at 'In plants there is etc.' First of all, then, he observes that, of the powers already enumerated, all are in some beings (men); some are in some beings (the other animals); and one only is in some others (plants). And having previously called them, not 'powers', but 'parts' of the soul, he clearly implies that the two terms mean the same. Now of these parts or powers there are five main types: the vegetative, sensitive, appetitive, locomotive and intellectual.

             § 280. Regarding this five-fold division two things must be made clear: (1) why the usual three-fold division of potencies into vegetative, sensitive and intellectual is set aside; and (2) why he has already made a four-fold division.

             § 281. As to (1) we should note that all potencies are defined by their proper acts, and operative potencies by activities. The soul, being a form, has operative potencies; hence by differences between its activities we have to differentiate between its potencies. Now, as the activity of anything is consequent upon and corresponds to its being, we have to study vital activities precisely in the living beings which display them.

             § 282. The being of things whose actuality is 'soul', i.e. of the animate beings that exist on this earth and are the subject of the present discussion, this being includes two factors: one, material, in which it resembles the being of all other material things; and the other, immaterial, by which it has something in common with the world of the higher substances.

             § 283. Now there is this difference between these two divisions of being, that in so far as a thing is material, it is restricted by its matter to being this particular thing and nothing else, e.g. a stone; whilst in so far as it is unmaterial, a thing is free from the restriction of matter and has a certain width and infinity, so that it is not merely this particular subject but, in a certain sense, it is other things as well. That is why everything pre-exists, somehow, in the higher immaterial substances, as in universal causes.

             § 284. But in the lower terrestrial natures there are two degrees of immateriality. There is the perfect immateriality of intelligible being; for in the intellect things exist not only without matter, but even without their individuating material conditions, and also apart from any material organ. Then there is the half-way state of sensible being. For as things exist in sensation they are free indeed from matter, but are not without their individuating material conditions, nor apart from a bodily organ. For sensation is of objects in the particular, but intellection of objects universally. It is with reference to these two modes of existence that the Philosopher will say, in Book III, that the soul is somehow all things.

             § 285. The activities, therefore, appropriate to living things in their material being are those we attribute to the vegetative soul. They fulfil the same purpose as the actions of inanimate beings, i.e. to attain and maintain existence; but they do this in a higher or nobler way. Inanimate bodies are brought into being and maintained by an exterior moving principle, whereas animate beings are generated by an intrinsic principle, i.e. seed, and are kept in existence by an intrinsic nutritive principle. It seems characteristic of living things that their activities should thus proceed from within themselves. But the purely immaterial activities of living things we identify with the intellectual part of the soul; while those in between belong to its sensitive part. Hence it is usual to distinguish three kinds of soul: vegetative, sensitive, intellectual.

             § 286. But since everything exists as formed in a certain way, the being of the sensible must have a sensible form, and the being of the intelligible an intelligible form. Now every form has by nature a certain trend or tendency whence proceed its activities or operations. Thus the form of fire tends naturally upwards (giving to fire its lightness) whence follows fire's activity which is the movement upwards. Now the trend that proceeds from a sensible or intellectual form is called sensitive or intellectual desire; as that of any form in nature is called a natural desire. And from this desire follows the activity of local movement. Here then is the explanation we required of the five-fold division of the powers of soul.

             § 287. And as to the second point, note that when Aristotle wished to show that soul was the life-principle in things that live, he divided these into grades; which are not the same as those different kinds of vital activity whence we get our division of the powers of the soul. For, since all things that sense also desire, desire or appetition does not constitute a distinct grade of animate being; so we are left with only four such grades.

             § 288. Then, at 'In plants there is only', he shows the interconnection of the powers of the soul, thus explaining what he said previously, that all these powers are in some things, some of them in some, and only one in some others. Here we have to consider that the completeness of the Universe requires that there should be no gaps in its order, that in Nature there should everywhere be a gradual development from the less to the more perfect. Hence, in the Metaphysics, Book VIII, Aristotle likens the nature of things to numbers; which increase by tiny degrees, one by one. Thus among living things there are some, i.e. plants, which have only the vegetative capacity,--which, indeed, they must have because no living being could maintain an existence in matter without the vegetative activities. Next are the animals, with sensitivity as well as vegetative life; and sensitivity implies a third power, appetition, which itself divides into three: into desire, in the stricter sense, which springs from the concupiscible appetite; anger, corresponding to the irascible appetite--both of these being in the sensitive part and following sense-knowledge; and finally will, which is the intellectual appetite and follows intellectual apprehension.

             § 289. That appetition exists in all animals he demonstrates in two ways. (1) All animals have at least one sense, touch; but where there is any sensation there is pleasure and pain, joy and sorrow. Now while joy and sorrow seem to spring from inward apprehension, pain and pleasure come from external sensations, especially from touch. But joy and sorrow necessarily imply some sweet or disagreeable object, i.e. something pleasant or painful. For everything touched is either congenial to the one touching, and then it gives pleasure; or uncongenial, and then it gives pain. But whatever can feel pleasure and pain can desire the pleasant. Since then all animals, without exception, have a sense of touch, all can desire.

             § 290. (2) This second argument begins at 'Further, all have', and runs thus. All animals have the sense that is aware of food; and this is touch; which is as necessary therefore to every animal as eating the food that agrees with it. The fact that it is touch that perceives food is clear if we consider that, as living bodies are made up of warm, moist, cold and dry elements it is of these that their food must consist; and these elements are just what touch is aware of. But 'other sense-objects', he says, do not, save indirectly, nourish living bodies; they do so only so far as they are involved in the objects of touch. Sound, colour, smell have nothing to do with food as such; they occur in food only in so far as things that sound or are coloured or odorous, are also hot, or cold, moist or dry. Savour, however, is reckoned a tangible quality--so that tasting is a sort of touch. Clearly, then, all animals have a sense-awareness of food.

             § 291. But whatever has this awareness can feel the two desires of nourishment, hunger and thirst. Hunger is desire for the hot and the dry elements, i.e. food; thirst for the cold and the moist, i.e. drink. Savour is a certain delectability in food and drink indicating a proper balance of the hot and cold, the moist and dry elements. It is more of a pleasure added to eating than a necessity. Desire, then, always accompanies touch.

             § 292. What imagination has to do with desire and sensitivity will be shown later.

             § 293. Now besides these three powers, the vegetative, the sensitive and the appetitive, some animals also have the capacity to move from one place to another. Some, too, i.e. human beings and any other kind of beings, if such exist, resembling or even perhaps excelling mankind, have, in addition to these four capacities, the power of understanding or intellect. The beings 'more excellent' are the immaterial substances and the heavenly bodies, the latter, however, only if they are alive. Among living corruptible beings the human race alone is endowed with intellect.

             § 294. For as intellect has no bodily organ, intelligent beings cannot be differentiated according to a physical diversity in the constitution of their bodily organs, as are the different species of animals (whose different constitutions cause them to sense in different ways).

             § 295. Then at 'It is therefore clear' he shows how his definition of soul is related to the 'parts' that we have enumerated. To understand him here we must remember what Plato said about universal ideas, that they had a separate existence of their own. He did not say, however, that objects which follow successively from each other, such as numbers and geometrical figures, had a universal idea, i.e. he did not posit a universal idea of Number apart from particular numbers--as, for him, there was a universal idea of Man in addition to all existing men; and this because the classes of number are, of their nature, derived successively from each other, so that the first of these, duality, is the cause of all the rest. There is no need to posit a general idea of Number as the cause of the numerical species. The same argument applies to geometrical figures. They follow each other in the same way as numbers: from the triangle comes the tetragon, and from the latter the pentagon.

             § 296. Aristotle, then, says that the idea of Soul is one in the same way as that of geometrical figure is one. Just as there is no figure existing apart from the triangle and the rest, as their common idea, so it is with the soul. There exists no soul apart from the parts which have been enumerated.

             § 297. But while there is (even for the Platonists), no figure existing apart from all figures, nevertheless one common definition can be found which answers to all figures, without being proper to any particular one. And the same is true of living beings. It would be ludicrous therefore to seek a common definition, whether of animals or anything else, which did not fit any particular living thing actually existing. On the other hand it will not do to look for a definition that will fit only one sort of soul, ignoring what all have in common. We need a common definition which must, however, be applicable to souls in particular.

             § 298. He goes on now to show the resemblance between the two definitions, namely of soul and of geometrical figure. In both cases what comes first is potentially in what follows. In figures the three-sided figure exists potentially in the square; for the square is divisible into two triangles. Likewise the sensitive life-principle contains the vegetative, both as potential, as it were, with respect to sensitivity, and also as a certain life-principle in itself. The same holds good with the other figures and the other divisions of soul.

414b 32-415a 22

THE SOUL'S POWERS CONTINUED THEIR INTERRELATION

HOW TO DEFINE EACH

             SO we must enquire in each particular case what the soul is of each: of plant, of man, of beast.§ 299

             It must be considered why they stand in this order: for there is no sensitive soul without the vegetative, yet in plants the vegetative exists apart from the sensitive. Again, there can be no sense apart from that of touch, but touch exists without the others; for many animals have no sight or hearing or sense of smell. Again, among sentient beings, some have local motion, others not. Last and least extensive of all [the species] that reasons and understands (as man and any other such). For mortal beings which possess reason have also all the other [powers], but reason is not found in all that have any one of the latter; some indeed have not even imagination, others live by this alone. The speculative intellect is another issue. Clearly then, whatever is the most precise definition with respect to each of the above will be that also of the soul.§§ 300-2