This study of Sigmund Freud's life and work sets out to provide an answer to the controversies which have raged for a century around one of the most influential of all modern thinkers. Tracing Freud's essentially religious personality to his childhood, it shows how the founder of psychoanalysis allowed his messianic dreams to shape the 'science' he created and how, in the diagnostic darkness which prevailed at the beginning of the twentieth century, he led his followers ever deeper into a labyrinth of medical error. The book is, at one and the same time, an intellectual biography, a comprehensive critique of Freud's theories, and an essay in cultural analysis. The nature of psychoanalytic doctrines and their rapid adoption by Western thinkers illustrate the main thesis: that our intellectual tradition remains dominated by rationalist theories of human nature and that these theories are in their turn based on forms of mind-body or 'angel-beast' dualism which are rooted in Judaeo-Christian religious teachings.