THE TENTH BOOK OF THE LAWS, which contains Plato's last word on cosmology and theology, has often been considered as presenting Plato's views in a more exoteric way in contrast with the more esoteric style of the Timaeus. And there are good reasons to think that this view is correct. Whereas the Timaeus stresses that "to find the maker and father of this All is difficult, and, having found it, it is impossible to communicate it to the crowd" (28c),(1) Plato is in Laws 10 intending to establish a "proemium" (prooimion, 887a-b) or rational foundation for his laws against impiety, which are supposed to be known by all. in this proemium Plato tries to argue for three propositions: (1) that the gods exist (887c--899d); (2) that they take care of human affairs (899d-905d); (3) that they cannot be bribed by sacrifices or prayers (905d-907b).(2) The underlying assumption is that learning these facts about the gods will also help to prevent impiety which, like any kind of vice, is often due to ignorance (885b).
If this is so, what most surprises us is that Plato does not however have qualms about introducing in this apologetic discourse a reference to an evil soul as acts alternative candidate to a good soul ruling over the universe (896e). This has provoked the most varied reactions, from ancient Platonistss attributing to Plato a dualism that would appear manichean to our eyes, to recent interpreters who have denied that Plato is at all concerned with the World-Soul in the Laws. It has also been very much debated whether the general account of Laws 10 is consistent with the Timaeus. This requires us to examine the status of soul and its connection with evil in Laws 10 against the background of Platb's cosmological account in earlier dialogues.
I shall try to show that Laws 10 is to be taken as an emphatic assertion of cosmic teleology--based on the supremacy of soul--that follows the spirit of the earlier dialogues and that involves an explicit rejection of any kind of evil World-Soul ruling over the whole cosmos. This rejection, however, does not do away with the existence of an "evil kind of soul," nor does it do away with the problem of evil in general, about which Plato seems to be worried probably more than ever, though at the same time he wishes more than ever to be convincing about the existence of teleology. This, as we shall see, gives the Laws a fluctuating tone between optimism and pessimism, which could nevertheless be resolved as pessimism about individual human affairs but optimism about the victory of goodness in the whole that will subsume any partial evil.
The priority of soul over body. Why does Plato need to "prove" that god exists? It is obvious that this need arises when god's existence is no longer evident or a matter of consensus, as it used to be (885e-886a), but has now been controverted by modern theories. It will no longer be sufficent to point to the "sun, moon, stars and earth, as instances of divinity," because many people would say "that these things are simply earth and stone" and bulks of inanimate things (886d-e, cf. 12.967c). These matelialists claim the priority of body over soul (891c) and posit nature (phusis), chance (tuche), or chance by necessity (tuche ex anankes) (889c) as the main cause of everything: the random motion, collision, and admixture of opposite properties of water, earth, fire, and air (like hot-cold, wet-dry, soft-hard) gave rise to the heavenly bodies and the universe in general (889b-c). "And all this, as they assert, not by reason (nous), god (theos) or art (techne) but . . . by nature and chance" (889c).
It is these materialists, then, who provide the scientific support for atheism. Plato purports to attack them by conversely establishing the priority of soul over body. To phusis understood as chance and necessity, Plato opposes his own principles, namely god and design (techne) and intellect (nous) as things akin to soul (889b-c, cf 892a-c). …