Tn many respects the field of psychical re search and of psychology is the same. though the methods and purpose of the investigators may he distinct. Hypnotism, subconscious activity, alterations of personality, hysteria, mental auto matisms, and related topics find recognition in the records of both. A type of such inquiry is 'crystal-gazing,' that is, the alleged power to see in a crystal or other reflecting surface a vis ual projection of shifting scenes and images, which upon examination can be referred to ex periences subconsciously assimilated. As illus trations of the exercise of the subconscious imag ination, the record of such instances possesses a distinct value for psychology. In the minds of some observers of such phenomena they, like other experiences, suggest the working of super normal mental processes, and cannot in many cases be interpreted upon the psychological prin ciples just indicated. Equally deserving of men tion are certain studies, purAued by persons interested in psychical research, that contribute to the psychology of deception. Such studies have shown how readily the reports of perform ances purporting, to give evidence of supernormal powers are vitiated by the effects of observation, by prejudice, by lack of technical knowledge, by lapses of memory and the like.
To the credit of psychical research must he placed a revival of interest in many worthy problems of psychology; the rescue from ob livion of important illustrative material; the contribution of illuminating aids to the compre hension of the culture history of the human race; and the social service of setting forth the per nicious and illusory character of certain systems of belief that threatened at various times the mental health of communities. To its disadvan
tage must be recorded the fostering of what is to sonic persons an unwholesome interest in the occult.
BIBLIOGRAPHY. The most important publicaBibliography. The most important publica- tions are those of the English Society for Psy chical Research, of which up to 1903 seventeen volumes have appeared. In 1884 there was formed an American Society for Psychical Re search which pnldished four volmnes before it merged its existence with that of the parent society. The best single volume surveying the field is Podmore's Studies in Psychical Research (London. 1897). Podmore's work on Modern Spirit u al ( 2 vols., New York, 1902) gives much information upon that as well as kindred topics. Other works worthy of mention in an outline bibliography are Andrew Lang. Cork-Lane and rom111071, Sense (London, 1894) ; Podmore, pparitions and Thought Transference (ib., 1894) ; Gurney. Alyers, and Podmore, Phantasms of the Living OIL 1886) ; Mason, Telepathy and the Subliminal Self (ih., 1897). In Jastrow, Fact and Fable in Psychol ogy (1 900 ) . will be found a critical survey of certain of the problems and positions of `psy chic•al research.'