Socrates' moral psychology is widely thought to be 'intellectualist' in the sense that, for Socrates, every ethical failure to do what is best is exclusively the result of some cognitive failure to apprehend what is best. Until fairly recently, the view that, for Socrates, emotions and desires have no role to play in causing such failure went unchallenged. This book argues against the orthodox view of Socratic intellectualism and offers in its place a comprehensive alternative account that explains why Socrates believed that emotions, desires and appetites can influence human motivation and lead to error. Thomas C. Brickhouse and Nicholas D. Smith defend the study of Socrates' philosophy and offer a new interpretation of Socratic moral psychology. Their novel account of Socrates' conception of virtue and how it is acquired shows that Socratic moral psychology is considerably more sophisticated than scholars have supposed.