15 (page 105)p. 105Psychology

One important distinction within the natural world is found in the fact that some natural substances are alive and others inanimate. What marks off the former from the latter is their possession of what in Greek is called psuchê. The word ‘psuchê’ (from which ‘psychology’ and other such terms derive) is usually translated as ‘soul’, and under the heading of psuchê Aristotle does indeed include those features of the higher animals which later thinkers associate with the soul. But ‘soul’ is a misleading translation. It is a truism that all living things – prawns and pansies no less than men and gods – possess a psuchê; but it would be odd to suggest that a prawn has a soul, and odder still to ascribe souls to pansies. Since a psuchê is what animates, or gives life to, a living thing, the word ‘animator’ (despite its overtones of Disneyland) might be used. (I shall generally keep to the conventional ‘soul’, but I shall also occasionally use ‘animator’.)

Souls or animators come in varying degrees of complexity.

Some things possess all the powers of the soul, others some of them, others one only. The powers we mentioned were those of nutrition, of perception, of appetition, of change in place, of thought. Plants possess only the nutritive power. Other things possess both that and the power of perception. And if the power of perception, then that of appetition too. For appetition consists of desire, inclination, and wish; all animals (page 106)p. 106possess at least one of the senses, namely touch; everything which has perception also experiences pleasure and pain, the pleasant and the painful; and everything which experiences those also possesses desire (for desire is appetition for the pleasant) … Some things possess in addition to these the power of locomotion; and others also possess the power of thought and intelligence.

Thought, in Aristotle’s view, requires imagination and hence perception; so that any thinking creature must be capable of perceiving. And perception never exists apart from the first principle of animation, that of nutrition and reproduction. Thus the various powers or faculties of the soul form a hierarchical system.

What is a soul or animator? And how do living creatures acquire one?

In his treatise On the Soul Aristotle offers a general account of what souls or animators are. He first argues that ‘if we are to state something common to every type of soul, it will be that it is the first fulfilment of a natural body which has organs’. He later observes that such an account is not particularly illuminating, and suggests, as an improvement, that ‘a soul is a principle of the aforesaid powers and is defined by them, namely by nutrition, perception, thought, movement’. Aristotle himself advises us not to spend too much time over these generalities but rather to concentrate on the different functions of the soul.

Yet the generalities contain something of importance. Aristotle’s first general account of the soul amounts to this: for a thing to have a soul is for it to be a natural organic body actually capable of functioning. The second general account explains what those functions are. Thus Aristotle’s souls are not pieces of living things, nor are they bits of spiritual stuff placed inside physical bodies; rather, they are sets of powers, sets of capacities or faculties. Possessing a soul is like (page 107)p. 107possessing a skill. A carpenter’s skill is not some part of him, responsible for his skilled acts; similarly, a living creature’s animator or soul is not some part of it, responsible for its living activities.

This view of the soul has certain consequences, which Aristotle was quick to draw. First, ‘one should not ask if the soul and the body are one, any more than one should ask such a question of a piece of wax and its shape or in general of the matter of anything and that of which it is the matter’. There is no problem of the ‘unity’ of soul and body, or of how soul and body can act upon each other. Descartes later wondered how on earth two things so different as body and soul could coexist and work together; for Aristotle such issues do not arise.

Secondly, ‘that the soul – or certain parts of it, if it is divisible into parts – is not separable from the body is not unclear’. Fulfilments cannot exist apart from the things that are fulfilled. Souls are fulfilments of bodies. Hence souls cannot exist apart from bodies, any more than skills can exist apart from skilled men. Plato had held that souls pre-existed the birth and survived the death of those bodies they animated. Aristotle thought that this was impossible. A soul is simply not the sort of thing that could survive. How could my skills, my temper, or my character survive me?

Aristotle’s general view of the nature of souls is elaborated in his detailed accounts of the different life-functions: nutrition, reproduction, perception, movement, thought. Such functions or faculties are functions or faculties of bodies, and Aristotle’s psychological investigations can take a biological turn without, as it were, changing the subject. Thus imagination, for example, is described as ‘a motion coming about by the agency of an act of perception’: an act of perception is a physiological change, and it may cause a further physiological change, which constitutes an imagination. Some may object that Aristotle ignores the psychological aspect of imagination by concentrating on its physiological (page 108)p. 108manifestations. But Aristotle holds that the psychology simply is the physiology, that souls and their parts are physical capacities.

On the Soul and the Parva Naturalia are governed by this biological attitude towards animation. In the Generation of Animals Aristotle asks where the soul or animator comes from: how do creatures begin to live? A popular view, accepted by Plato, had it that life begins when the soul enters the body. Aristotle comments: ‘clearly, those principles whose actuality is corporeal cannot exist without a body – for example, walking without feet; hence they cannot come in from outside – for they cannot enter it alone (for they are inseparable), nor yet in some body (for the semen is a residue of food that is undergoing change).’ The ‘principles’ or powers of the soul are corporeal principles – to be animated is to be a body with certain capacities. Hence to suppose that those capacities could exist outside any body is as absurd as to imagine that walking could take place apart from any legs. The soul cannot simply drift into the foetus from outside. (In principle, it could arrive ‘in some body’, that is, in the semen; but in fact the semen is the wrong sort of stuff to carry or transmit these capacities.)

Aristotle’s accounts of nutrition, reproduction, perception, desire, and movement are all consistently biological. But consistency is threatened when he turns to the highest psychological faculty, that of thought. In the Generation of Animals, immediately after the sentences just quoted, Aristotle continues: ‘Hence it remains that thought alone comes in from outside, and that it alone is divine; for corporeal actuality has no connection at all with the actuality of thought.’ Thought, it seems, can exist apart from body. The treatise On the Soul speaks of thought with special caution, hinting that it may be separable from body. In what is perhaps the most perplexing paragraph he ever wrote, Aristotle distinguishes between two sorts of thought (later known as ‘active intellect’ and ‘passive intellect’). Of the first of these he says: ‘this thought is separable and impassive and unmixed, being essentially (page 109)p. 109actuality … And when separated it is just what it is, and it alone is immortal and eternal.’

The special status of thought depends upon the view that thinking does not involve any corporeal activity. But how can Aristotle hold such a view? His general account of the soul makes it plain that thinking is something done by ‘natural organic bodies’, and his particular analysis of the nature of thought makes thinking dependent upon imagination and hence upon perception. Even if thinking is not itself a corporeal activity, it requires other corporeal activities in order to take place.

Aristotle’s treatment of thought is both obscure in itself and hard to reconcile with the rest of his psychology. But neither that fact, nor the various errors and inexactitudes in his physiology, should dim the light of his work on psychology: it rests on a subtle insight into the nature of souls or animators, and it is persistently scientific in its approach to psychological questions.