This result of more or less _a priori_ speculation subsequently received striking _a posteriori_ confirmation from the work of a large number of those engaged in different branches of psychological investigation; including psycho-pathologists like Charcot, Janet, Morton Prince, students of Psychical Research like F. W. H. Myers, Gurney, Hodgson and experimental psychologists like Müller and Schumann, Knight-Dunlap and Ach. The extensive data contributed from these sources seemed to afford convincing proof that processes such as we are ordinarily inclined to regard as being invariably accompanied by consciousness, can occur, at any rate under certain circumstances, without the knowledge or conscious co-operation of the person by whom they are accomplished. The penetrating insight, the fearless logical consistency, combined with the exceptional ability of detecting widespread but hidden identities and similarities which have distinguished the work of Freud enabled him to show that, far from being operative only under certain special or rare conditions, the unconscious mental forces of the human mind are continually active during waking life and even during sleep, and exercise a profound influence on the whole course of consciousness and conduct. As the result of the far reaching investigations of Freud and of his followers, it would seem indeed that we shall probably have to look to the Unconscious for an understanding of the ultimate nature of all the deepest and most powerful motive forces of the mind. [Sidenote: Psycho-analysis applied to the study of the family] As is now well known, the psycho-analytic method originated as a method for the study and treatment of hysteria and other functional nervous disorders, which were found to depend upon the influence of unconscious mental factors. The discovery of the importance of the feelings and tendencies connected with family life, especially as affecting these unconscious factors, dates from this time of the earliest use and application of Psycho-Analysis. As in the case of so many other problems upon which the method has cast light, Freud himself was the first to show something of the intimate nature of the influence exerted by the family relationships. Certain aspects of the subject were already revealed in the Papers on Hysteria, published conjointly with Breuer in 1895--a work which indicated for the first time something of the importance and nature of the subsequently developed psycho-analytic method. [Sidenote: The child's love to its parents]