THE present volume is somewhat in the nature of a sequel to “The Riddle of Personality,” published six years ago. In that book I reviewed the results of modern psychological research in the realm of the abnormal and the seemingly supernormal, with the special purpose of making clear their bearings on the problem of the nature and possibilities of man. Having this special purpose in mind, it was inadvisable to attempt any topical and detailed treatment of the phenomena made the subject of scientific investigation. Such a method of treatment, no matter how it might have added to the interest of the book, would inevitably have obscured its message to the reader.