If the term may at all be brought within the circle of the sciences, it certainly there assumes a somewhat unique position. It naturally becomes the analogue, or it may be the rival of Psychology; yet its precise status and its logical relations to other departments of scientific research are far from obvious. The modern conception of Psychology is generously comprehensive; it encompasses the endlessly variable and complex processes of human mentality; it pursues with enthusiasm the study of developmental processes of intelligence in childhood, in the animal world, in the unfoldment of the race; it studies, for their own value, the aberrant and pathological forms of mental action, and brings these into relation with, and thus illuminates the comprehension of the normal. It forms affiliations with physiology and biology and medicine, with philosophy and logic and ethics, with anthropology and sociology and folk-lore; it borrows freely from their materials, and attempts to interpret the materials thus borrowed from the psychological point of view and to infuse into them its distinctive spirit. Surely Psychical Research should be able to find a nook in so commodious a home; if the problems of Psychical Research are legitimate members of the psychological family, some provision should be possible for their reception within the old homestead. Nor does this group of problems represent a difference of school, in some such way as the homœopathists represent a secession from the regular school of medicine; nor can it be regarded as the special study of the unusual and the abnormal in the sphere of mind, and thus stand in the relation which teratology or pathology bears to physiology and anatomy: for in that event it would constitute a simple division of Abnormal Psychology, and although Psychical Research has close alliance with the latter, it cannot be, and is unwilling to be regarded as a subordinate portion of that domain.