This book links Plato and Epicurus, two of the most prominent ethicists in the history of philosophy, exploring how Platonic material lays the conceptual groundwork for Epicurean hedonism. It argues that, despite their significant philosophical differences, Plato and Epicurus both conceptualise pleasure in terms of the health and harmony of the human body and soul. It turns to two crucial but underexplored sources for understanding Epicurean pleasure: Plato's treatment of psychological health and pleasure in the Republic, and his physiological account of bodily harmony, pleasure, and pain in the Philebus.Kelly Arenson shows first that, by means of his mildly hedonistic and sometimes overtly anti-hedonist approaches, Plato sets the agenda for future discussions in antiquity of the nature of pleasure and its role in the good life. She then sets Epicurus' hedonism against the backdrop of Plato's ontological and ethical assessments of pleasure, revealing a trend in antiquity to understand pleasure and pain in terms of the replenishment and maintenance of an organism's healthy functioning.