Sado-masochism has become an influence on art, fashion, literature and thought. Who are the masochists, and why are they doing it? Is is a dangerous perversion, or a harmless, playful pastime? Addressing these questions, this book presents a portrait of human longing, curiosity and eroticism, drawing on a variety of literary, psychoanalytic and cultural sources, from Freud and Sacher-Masoch's "Venus in Furs" to David Lynch films and "The Story of O".