Akrasia in the Protagoras and the Republic

Although it is a commonplace that the Protagoras and the Republic present different views of akrasia, the nature of the difference is not well understood. I argue that the logic of the famous argument in the Protagoras turns just on two crucial assumptions: that desiring is having evaluative beliefs (or that valuing is desiring), and that no one can have contradictory preferences at the same time; hedonism is not essential to the logic of the argument. And the logic of the argument for the division of the soul in the Republic requires the rejection of just the second of these assumptions, but not the evaluative conception of desire. I also maintain that Plato was aware, at the time of composition, of these features of the argumentation of his dialogues. Finally, I argue that there is reason to think that, even at the time of the Protagoras, Plato held the conception of the soul expressed in the Republic, and not anything like that expressed in the famous argument of the Protagoras. The Protagoras view, even without hedonism, is a poor expression of the thesis that virtue is knowledge