This book, first published in 1962, is based on a series of lectures first given at Cambridge University in 1959 and 1960, dealing with psychical research, i.e. the scientific investigation of ostensibly paranormal phenomena.

This book, first published in 1962, is based on a series of lectures first given at Cambridge University in 1959 and 1960, dealing with 'psychical research' - i.e. the scientific investigation of ostensibly paranormal phenomena. Split into three sections, Professor Broad's study examines numerous issues relating to psychical theory, including guessing, hallucinatory quasi-perception and trance-mediumship.