This introductory text examines the psychology, philosophy, and neuroscience of consciousness, emphasizing the strengths of a scientific approach to studying the mind. It surveys the full range of altered states of consciousness including sleep and dreams, hypnotic and meditative states, anesthesia, and drug-induced states. 'Finally, a brilliantly written, accessible, and accurate synthesis on one of science's biggest taboos: the study of consciousness. There is no topic avoided by Trevor Harley: animal versus machine consciousness, coma, psychedelics, meditation, our sense of self, even psychism, are all covered. It is the authoritative text all students and researchers have been waiting for.' Steven Laureys, University Hospital of Liège