With a nod to the more rational functions of the human mind in terms of the conscious, explorer Estabrooks turns his attention to its less accepted and even less understood phenomena. The experiments with extra sensory perception, the appearance of multiple personalities, the capacities of ""idiot savants"" who can function brilliantly in one area while requiring institutional care, are among such phenomena. Estabrooks' essential interest, however, lies in the promotion of scientific hypnosis in the areas of learning, psychosomatic and mental ills, even in such differing practicalities as building up a job hunter's self confidence and in creating the impregnable, because unconsciously informed, spy. Aware of the dangers of hypnosis in its practice and of moral reservations against it, the author reminds us that advertising is a form of such suggestion, that it works in our lives daily. His own experiments and treatments obviously give rise to optimism as to its use as a valuable tool. Other books: Hypnotism and Spiritism. Of speculative interest.