The mystery of how, when, and why people change lies at the heart of the therapy process. Many authors have given shape to different pieces of the puzzle. Here at last is a book that provides the integrative framework within which these pieces can fit together. Why is it so difficult for people to change? What can be done to maximize the chances for success? To answer these questions, this sweeping book travels across a vast intellectual terrain, encompassing the history of ideas about human nature, developments in the cognitive sciences, artificial intelligence, evolution, psychobiology, developmental psychology, theories of emotion, the psychology of self, and more. The author then applies the theory to practice, drawing on his wide personal experience with hundreds of clients in transition to outline a model of significant change. Mahoney identifies common themes and experience patterns associated with dramatic change, emphasizing the role of emotionality and cognitive processes, and challenging long-revered notions about thinking and feeling. Here is an important work that will point researchers in new directions, will help practicing therapists adapt theoretical concepts to helping patients change, and will make fascinating reading for anyone exploring his or her own life journey.