From a survey of the literature of Psychical Research one might readily draw the inference that whereas Psychology studies the recognized and explicable phases of mental phenomena, Psychical Research is occupied with the disputed and mysterious. One might also conclude that whereas Psychology is concerned with the phenomena commonly associated with mental activities and their variation under normal as also under unusual and pathological circumstances, Psychical Research is interested in the demonstration of supernormal faculties, and in the establishment of forms of mentality that diverge from and transcend those with which every-day humanity is permitted to become familiar; and that, moreover, in some of its excursions Psychical Research does not limit itself to mental manifestations, but investigates undiscovered forms of physical energy, and seriously considers whether behind and beyond the world of phenomena there is another and a different world, in which the established order and the mental and material laws of this planet do not obtain. But the unwarranted character, not to say absurdity, of such a differentiation or classification is at once apparent, if we attempt to carry it over into other departments of science. Speculations in regard to the constitution of the earth's centre or as to the future of our planet, if legitimate in character, are as readily incorporable into geology as the consideration of more definite and better known phenomena; biologists recognize that there are mythical as well as anomalous portions of their domain, but do not consider that freaks of nature either destroy the validity of anatomical and physiological principles, or demand a totally distinct and transcendent organization or method for their study. The chemist may become interested in the examination of what was really done when it was supposed that other metals were converted into gold; the physicist may become interested in the applications of electricity and magnetism, of optical reflections and images in the production of stage illusions; but the conception of chemistry and of physics naturally embraces considerations of the growth, the errors, and the applications of these sciences. And while these comparisons do not furnish a complete parallel to the relation that seems to pertain between Psychology and Psychical Research, yet it is as true in the one case as in the others, that the differentiation of a group of problems on the basis of unusualness of occurrence, of mysteriousness of origin, of doubtful authenticity, or of apparent paradoxical or transcendent character, is as illogical as it is unnecessary. The legitimate problems of Psychical Research are equally and necessarily genuine problems of Psychology, that require no special designation. They need not be especially important, nor interesting, nor profitable, nor well comprehended problems of Psychology, but they belong there if they are scientific problems at all.