Abstract

This essay examines the early Stoic debates concerning the number of virtues and the differentiation among them. It begins with the defense of virtue’s unity offered by the heterodox Stoic Aristo of Chios and with a comparison between the definitions that Aristo and Zeno offered for the four primary virtues. Aristo maintained that virtue consists exclusively in the knowledge of good and bad. Zeno and his successors presented the virtues as epistemic dispositions whose scopes differ. I conclude that by adding the knowledge of indifferents to the definition of virtue, Zeno and his successors were able to avoid the circularity to which Aristo’s definition of virtue fell victim while providing a way to differentiate among the virtues.