This original study reveals the importance of ancient Cynicism in defining the Enlightenment and its legacy. Louisa Shea explores modernity's debt to Cynicism by examining the works of thinkers who turned to the ancient Cynics as a model for reinventing philosophy and dared to imagine an alliance between a socially engaged Enlightenment and the least respectable of early Greek philosophies. While Cynicism has always resided on the fringes of philosophy, Shea argues, it remained a vital touchstone for writers committed to social change and helped define the emerging figure of the public intellectual in the 18th century. Shea's study brings to light the rich legacy of ancient Cynicism in modern intellectual, philosophical, and literary life, both in the 18th-century works of Diderot, Rousseau, Wieland, and Sade, and in recent writings by Michel Foucault and Peter Sloterdijk. Featuring an important new perspective on both Enlightenment thought and its current scholarly reception, The Cynic Enlightenment will interest students and scholars of the Enlightenment and its intellectual legacy, 18th-century studies, literature, and philosophy.