Abstract

This dissertation discusses the moral psychology presented in Plato's early and middle dialogues. Chapters I and II examine the moral psychology developed in the early dialogues to support the Socratic paradoxes that virtue is knowledge and that all virtues are one. Chapter III argues that Plato rejects this early moral psychology in the middle dialogues. Chapters IV and V examine the moral psychology developed in the middle dialogues to replace it. ;Specifically, Chapter I discusses the early Plato's contention that the good is the only object of desire through an examination of passages from the Lysis, Meno 77-78 and Symposium 199-206. Chapter II discusses the related view that persons always choose the action they think is best through an examination of Protagoras 352-358 and Gorgias 467-468. ;Chapter III traces Plato's rejection of his early moral psychology in the middle dialogues, particularly in the Phaedo and at Republic 437-439. ;Chapter IV then discusses the doctrine of parts of the soul developed in the Republic, with particular attention to the arguments of Republic 436-441. Chapter V discusses Plato's views about the role of these parts of the soul in the moral development of the individual, through a discussion of Plato's ideal educational scheme at Republic II to III, Plato's views on love in the Phaedrus and Plato's views on the development of different types of characters at Republic VIII to IX.