The entire legacy of Jacques Lacan is permeated by his deep interest in psychosis and psychotic phenomena. This book examines Lacan's contribution to our understanding of psychosis, proposing that his workcan best be framed in terms of four broad periods. Each period contains a different set of key concepts, together with a number of crucial texts containing references to psychosis. Stijn Vanheule explains the precise meaning of these concepts and their implication for the clinic of psychosis, focusing on Lacan's discussion of clinical cases and literary works, and his critical dialogue with related disciplines such as psychology, psychiatry, philosophy, and linguistics. Synthesising ideas from Lacan's entire oeuvre, this book, now in paperback, sheds light on the evolution of his theory and provides a valuable tool for students and scholars.