Authors of Greek and Roman philosophical protreptics imitate a kind of exhortation initially associated with Socrates, creating a thread of typically protreptic intertextuality that classifies protreptic as a genre of philosophical literature. Tracing this intertextuality from the Socratic authors to Boethius, the book shows how Greek and Roman protreptics define philosophy as a revisionary form of education, articulate the ultimate goals of this education, and associate their authors and audiences with philosophy as a new discursive practice and a new way of living. These texts constitute the first chapter in the history of educational revision and thus offer thoughts that continue to inform every debate on educational goals.