This attempt involves me in a verbal duel with my wife, which lasts into the small hours of morning. It involves the everlasting debate between the vitalists and the mechanists, which had best be left to Dr. Watson and Professor McDougall, and the others who are no more able than I am to look at the neurons of the brain in action, to see what happens. But I insist that until Craig and Dr. Watson, Professor Eddington and Mrs. Eddy have found out positively whether the universe is all mind or all matter, I must go on speaking in the old-fashioned way, as if there were two worlds, the physical and the mental, two sets of phenomena which interact one upon the other continuously, even though the manner of this happening is beyond comprehension. With this much apology, I obtain permission to put forth my humble guess as to the part played by mental concentration in the causing of telepathy, clairvoyance, and trance phenomena. It seems to me that the process of intense concentration may cause the nervous energy, or brain energy, whatever it is, to be withdrawn from some of the brain centers and transferred to others; and it may be this displacement and disturbance of balance which accounts for such phenomena as catalepsy, automatism, and somnambulism. Portions of the mind which are ordinarily below the level of consciousness are raised to more intense forms of activity. New levels of mind are tapped, new “personalities” or faculties are brought into action, and persons under hypnotism develop mental powers they do not consciously possess.