This book examines the philosophical and political relevance of perversion in the works of three key representatives of contemporary philosophy and psychoanalysis: Gilles Deleuze, Giorgio Agamben and Jacques Lacan. Perversion is often understood simply in terms of cultural or sexual phenomena. By contrast, Boštjan Nedoh places perversion at the heart of philosophical, ontological and political issues in the works of Deleuze, Agamben and Lacan. He examines the relevance of their discussions of perversion for their respective critical ontological projects. By tracing the differences between these thinkers’ understanding of perversion, the book finally draws lines of delimitation between the vitalist and the structuralist or psychoanalytic philosophical positions in contemporary philosophy.