Plato therefore is wise when, in treating of the All, he puts the body in its soul, and not its soul in the body, and says that, while there is a region of that soul which contains body, there is another region to which body does not enter- certain powers, that is, with which body has no concern.And what is true of the All-Soul is true of the others.
There are, therefore, certain soul-powers whose presence to body must be denied.
The phases present are those which the nature of body demands:
they are present without being resident- either in any parts of the body or in the body as a whole.
For the purposes of sensation the sensitive phase of the soul is present to the entire sensitive being: for the purposes of act, differentiation begins; every soul phase operates at a point peculiar to itself.
23.I explain: A living body is illuminated by soul: each organ and member participates in soul after some manner peculiar to itself; the organ is adapted to a certain function, and this fitness is the vehicle of the soul-faculty under which the function is performed; thus the seeing faculty acts through the eyes, the hearing faculty through the ears, the tasting faculty through the tongue, the faculty of smelling through the nostrils, and the faculty of sentient touch is present throughout, since in this particular form of perception the entire body is an instrument in the soul's service.
The vehicles of touch are mainly centred in the nerves- which moreover are vehicles of the faculty by which the movements of the living being are affected- in them the soul-faculty concerned makes itself present; the nerves start from the brain.The brain therefore has been considered as the centre and seat of the principle which determines feeling and impulse and the entire act of the organism as a living thing; where the instruments are found to be linked, there the operating faculty is assumed to be situated.But it would be wiser to say only that there is situated the first activity of the operating faculty: the power to be exercised by the operator- in keeping with the particular instrument- must be considered as concentrated at the point at which the instrument is to be first applied; or, since the soul's faculty is of universal scope the sounder statement is that the point of origin of the instrument is the point of origin of the act.
Now, the faculty presiding over sensation and impulse is vested in the sensitive and representative soul; it draws upon the Reason-Principle immediately above itself; downward, it is in contact with an inferior of its own: on this analogy the uppermost member of the living being was taken by the ancients to be obviously its seat; they lodged it in the brain, or not exactly in the brain but in that sensitive part which is the medium through which the Reason-Principle impinges upon the brain.They saw that something must be definitely allocated to body- at the point most receptive of the act of reason- while something, utterly isolated from body must be in contact with that superior thing which is a form of soul [and not merely of the vegetative or other quasi-corporeal forms but] of that soul apt to the appropriation of the perceptions originating in the Reason-Principle.
Such a linking there must be, since in perception there is some element of judging, in representation something intuitional, and since impulse and appetite derive from representation and reason.The reasoning faculty, therefore, is present where these experiences occur, present not as in a place but in the fact that what is there draws upon it.As regards perception we have already explained in what sense it is local.
But every living being includes the vegetal principle, that principle of growth and nourishment which maintains the organism by means of the blood; this nourishing medium is contained in the veins; the veins and blood have their origin in the liver: from observation of these facts the power concerned was assigned a place;the phase of the soul which has to do with desire was allocated to the liver.Certainly what brings to birth and nourishes and gives growth must have the desire of these functions.Blood- subtle, light, swift, pure- is the vehicle most apt to animal spirit: the heart, then, its well-spring, the place where such blood is sifted into being, is taken as the fixed centre of the ebullition of the passionate nature.
24.Now comes the question of the soul leaving the body; where does it go?
It cannot remain in this world where there is no natural recipient for it; and it cannot remain attached to anything not of a character to hold it: it can be held here when only it is less than wise, containing within itself something of that which lures it.
If it does contain any such alien element it gives itself, with increasing attachment, to the sphere to which that element naturally belongs and tends.
The space open to the soul's resort is vast and diverse; the difference will come by the double force of the individual condition and of the justice reigning in things.No one can ever escape the suffering entailed by ill deeds done: the divine law is ineluctable, carrying bound up, as one with it, the fore-ordained execution of its doom.The sufferer, all unaware, is swept onward towards his due, hurried always by the restless driving of his errors, until at last wearied out by that against which he struggled, he falls into his fit place and, by self-chosen movement, is brought to the lot he never chose.And the law decrees, also, the intensity and the duration of the suffering while it carries with it, too, the lifting of chastisement and the faculty of rising from those places of pain-all by power of the harmony that maintains the universal scheme.