The main object of this book is to draw attention to the importance of hypnotism and its phenomena, in order to stimulate inquiry into what is still a mysterious and unexplored subject. This I have already endeavoured to do in an earlier book – Hypnotism and Suggestion in Daily Life, Education and Medical Practice – published in 1910, since when I have gained so much additional experience that an entirely new work is but justice.

The literature since the first edition has been reviewed and material from it has been inserted, with particular emphasis on experimental contributions. Major additions are made in the sections on speech abnormalities, constitutional psychopathic inferiority, behavior effects of epidemic encephalitis, and psychotherapy. The chapters on psychoneuroses now precede those on the psychoses. The revised work consists of 21 chapters and an index; bibliographies are presented in footnotes and at the ends of chapters.