In Timaeus’s story, mortals must exist because otherwise the cosmos would be incomplete. But mortals incorporate an immortal element: the rational soul or the intellect. The Demiurge creates these intellects from the same sort of incorporeal material as he used to create the cosmic soul: a complex blend of Being, Sameness, and Difference (35a1 ff.). He instructs them for life under mortal conditions, and hands them over to his ancillary gods who will provide them with mortal bodies. The aim of this chapter is to understand these themes. The most important points are that the immortal souls in question are distinct from the cosmic soul, although of similar composition; they are plural and individualised from their inception; and they are essentially oriented towards mortal embodiment and moral responsibility for embodied action.
Let us begin with an extended quotation, which I have divided into paragraphs corresponding to stages of the story:
(1) [41a] When all the gods had come to birth, both all that make their circuits obviously and all that manifest themselves just as they will, the generator of this universe spoke to them thus: ‘O gods – gods of whom I am maker and of whose works I am father, nothing that has come to be through me can be undone unless I will it. What has been fastened can in all cases be undone, but [41b] what has been fitted together by fine workmanship and is in good condition <only> an evil being would will to undo. Therefore, although because you have come to be you are not absolutely immortal and indissoluble, you will not be undone nor will the fate of death be upon you, since your allotted portion is my own will: a bond greater and more sovereign than those by which you came to be fastened together when you were coming into being. So now take in what I tell you, showing you my mind. Mortal kinds, three in number, remain as yet ungenerated: but if these do not come into being the world [ouranos] will be incomplete. For it [41c] will not have within itself the totality of kinds of living beings: but it must have them if it is to be properly complete. But if it were through me that these came to be and got their share of life, they would be equals of the gods. Thus so that there should exist mortal beings, and so that this All should truly be the sum of things, it is for you to turn in accordance with your nature to the fashioning of the animals, imitating that efficacy of mine by which you yourselves came to be. And whatever in them deserves to share the name of immortals, <namely> a part called god-like which exercises rule in those of them whose will at all times is to follow righteousness and to follow you – this part I myself shall sow, and having thus made a beginning [41d] shall hand over; for the rest, do you, weaving mortal to immortal, bring to completion [apergazesthe] living creatures: bring them to birth, give them nourishment and make them grow, and as they perish receive them back again.’
(2) Thus he spoke, and turning again to the mixing bowl he had used before, the one in which he had blended and mixed the soul of the All, he poured in what was left over of the former <materials>, mixing them in a way in the same fashion, only this time <to form a mixture> not in the same way unvaryingly free of contamination, but of second and third quality. And when he had compounded the whole, he divided it into souls equal in number to the stars, and [41e] assigned each soul to one particular star, and mounting <each> as if on a vehicle he showed them the nature of the All and told them the fated laws: the first birth would be ordained as one and the same for all of them, so that no one would be disadvantaged by him; and having been sown into the instruments of temporal lengths [organa chronôn], each into the one that is proper to it, they must be born as [42a] the most god-revering of animals; and human nature being twofold, its superior part would be such a kind as would later be called ‘man’ [anêr]. So whenever they came of necessity to be implanted in bodies, and of their bodies something would be passing in and something passing out: first, sense-perception would necessarily arise, innate and the same for all, the effect of violent impacts; and second would arise passionate love [erôs] mixed with pleasure and pain; and in addition to these fear and temper [thumos] and [42b] all the feelings that go with these, and all whose nature is disparate from them and opposed. If they mastered these they would live in righteousness, but if mastered by them, in unrighteousness. And he who lived well for the appropriate amount of time would be conveyed back to the habitation of his companion star and would have a happy and congenial life; but if he failed in this he would at [42c] his second birth change to a woman’s nature. And if under these conditions he still continued in depravity, then in accordance with the similarity determined by the mode of his degeneration – by the coming about of that mode – he would at each stage change into some particular bestial nature resembling it; and the toils of these vicissitudes would not cease for him until he drew together into his internal circuit of the Same and Similar that chaotic mass [ton polun ochlon] of fire and water and air [42d] and earth – his new accretion, turbulent and irrational – and conquered it by reason, and so returned to the form of his first and best condition.
(3) After delivering to them all these ordinances so that he would be guiltless [anaitios] of their subsequent individual depravity [tês epeita kakias hekastôn], he set about sowing: into the earth some of them, into the moon some of them, and the others into all the other instruments of time. After the sowing, he passed to the new gods the task of moulding mortal bodies; and the rest of the human soul, the part that still needed [42e] to be added and all that this implies, <he gave> to them to produce and hold in charge, piloting the mortal animal in the best and most expert [kallista] way they could except for such evils as it to itself would cause.
(4) He for his part, having delivered all these instructions, took up station in his own characteristic attitude [emenen in tô(i) heautou kata tropon êthei]; and as he so stayed his children heeded their father’s injunction and set about obeying it. Having received Mortal Animal’s immortal principle [athanaton archên thnêtou zô(i)ou], they imitated their own maker: borrowing from the cosmos portions of fire, earth, water, and air [43a] on condition that these would be paid back again, they cemented the takings together – not with the indissoluble bonds with which they themselves were held together – but fusing them together by means of closely arrayed rivets so small as to be invisible they made in each case one body out of all of them, and bound the revolutions of the immortal soul into a flowing-in-flowing-out body. (41a3–43a6)