Moral Evil and Ignorance in Plato's Ethics

It is universally agreed that Plato inherited from Socrates, and consistently maintained to the end, the doctrine that no man does evil of set purpose—οδες κν μαρτνει—but because he mistakes evil for good. All moral evil, therefore, for Plato, involves ignorance. There are, however, two passages, one in the Sophist, the other in Laws ix, which on the face of them appear to recognize a type of moral evil in which ignorance is not involved, a type which is indeed contrasted with that arising from ignorance. These passages have not, of course, been overlooked by scholars: they are regularly referred to in the best-known accounts of Platonic ethical theory; yet I do not think they have been sufficiently considered, nor is a clear answer forthcoming to the question whether or no in these later dialogues Plato really intends, as he seems to intend, a modification of his earlier ethical doctrine. My purpose is to show that he does not, and to account if possible for his apparent inconsistency