The Marquis de Sade is famous for his forbidden novels like Justine, Juliette, and the 120 Days of Sodom. Yet, despite Sade's immense influence on philosophy and literature, his work remains relatively unknown. His novels are too long, repetitive, and violent. At last in The Philosophy of the Marquis de Sade, a distinguished philosopher provides a theoretical reading of Sade. Airaksinen examines Sade's claim that in order to be happy and free we must do evil things. He discusses the motivations of the typical Sadean hero, who leads a life filled with perverted and extreme pleasures, such as stealing, murder, rape, and blasphemy. Secondary sources on Sade, such as Hobbes, Erasmusm, and Brillat-Savarin are analyzed, and modern studies are evaluated. The Philosophy of the Marquis de Sade greatly enhances our understanding of Sade and his philosophy of pain and perversion.