Much of the scholarship on Thomas Jefferson characterizes him as a consummate immoralist. Yet he had a keen interest in morality and most of his reading-when he was not immersed in politics-was for moral study. Jefferson once told his physician, Vine Utley, that he seldom went to sleep without first reading something morally inspiring. Some Jefferson scholars consider him at best a moral dilettante with incoherent views. Others see him as a Stoic, interested in virtue as measured by intentions and outcomes, who in later life became an Epicurean, weighing pleasure versus ends. Drawing on a careful reading of his writings and an examination of his known readings on morality, this study argues that Jefferson developed early a consistent moral sense-Stoical in essence and focused on his own moral improvement-and maintained it throughout his life.