The idea that the mind exists as an immaterial entity separate from the body is a myth. We perpetuate this myth by our continued use of the word ¿psychology¿, which literally means the study of the mind, soul or spirit. Contemporary psychologists do not study the mind or the soul. They study human and animal behaviour. This book addresses one of the most amazing blind-spots in psychology ¿ the failure by psychologists to recognize that all the so-called psychological phenomena are, at all times and in all respects, physical, rather than mental or immaterial processes. To illustrate this point, the author attempts to show that concepts from physics, chemistry, and biology are necessary and sufficient to explain all behaviour. Behaviours are actions or motions, which, in terms of physics, imply force, energy, and matter. The book ends with a discussion of the implications for adopting a physicalist approach to all, and not just some, disciplines in psychology.