While the theories of Matte-Blanco about the structure of the unconscious and the way in which it operates are generally recognised to be the most original since those of Freud, for many people the ways in which his ideas are expressed, including the use of terminology from mathematics and logic, make them difficult of access. Eric Rayner has written the first clear introduction to Matte-Blanco's key concepts for psychotherapists and psychoanalysts and all those concerned with moving psychoanalytic thinking forward. He sets out the central ideas in a way which is easy to understand and then shows, with examples, how they relate to clinical practice. He also describes how the ideas are related to those of people in other disciplines - mathematics, logic, psychology (specifically Piaget), and anthropology, among others. Drawing on the work of a group of people who have been inspired by Matte-Blanco's thinking to extend their own ideas and test them out in the consulting room, this book reveals the significance of Matte-Blanco's thought for future research.