This book investigates the nature and validity of extrasensory perception (ESP) through a synthesis of historical accounts and contemporary research. Rosalind Heywood, a prominent researcher in the field of psychical studies, utilizes her extensive background in the Society for Psychical Research to examine various phenomena such as telepathy, clairvoyance, and precognition. The text provides a structured framework for evaluating anecdotal evidence alongside early experimental data to determine if human consciousness possesses capabilities beyond the five traditional senses.

Experts in the field of parapsychology recognize this work as a significant historical overview of mid-20th-century psychical research. Readers frequently note the accessible yet scholarly tone of the prose, which balances academic rigor with an interest in the unexplained.