Forms and Causes in Plato's Phaedo

Gregory Vlastos has argued that Aristotle and other commentators on the Phaedo have mistakenly interpreted Plato’s Forms to be efficient causes. While Vlastos is correct that the Forms by themselves are not efficient causes, because of his neo-Kantianism he has misunderstood the close connection between the Forms and the explanation of change, including teleological change. This paper explores the connection in Plato’s Phaedo between the Forms, the nature of change, and efficient causality, and argues that Aristotle’s remarks are not as misplaced as Vlastos claims.