So long as official science excludes psychoanalysis from general discussion, as pure nonsense, we cannot be astonished if those belonging to other faculties master this material even before the medical profession. And this will occur the more because psychoanalysis is a general psychological method of investigation, as well as a heuristic principle of the first rank in all departments of mental science (“Geisteswissenschaften”). Chiefly through the work of the Zürich School, the possibility of applying psychoanalysis to the domain of the mental diseases has been demonstrated. Psychoanalytical investigation of dementia præcox, for instance, brought us the most valuable insight into the psychological structure of this remarkable disease. It would lead me too far were I to demonstrate to you the results of those investigations. The theory of the psychological determinants of this disease is already in itself a vast territory. Even if I had to treat but the symbolic problems of dementia præcox I should be obliged to lay before you so much material, that I could not possibly master it within the limits of these lectures, which must give a general survey. The question of dementia præcox has become so extraordinarily complicated because of the quite recent incursion on the part of psychoanalysis into the domains of mythology and comparative religion, whence we have derived a deeper insight into ethical psychological symbolism. Those who are well-acquainted with the symbolism of dreams and of dementia præcox have been greatly impressed by the striking parallelism between modern individual symbols and those found in folk-lore. The extraordinary parallelism between ethnic symbolism and that of dementia præcox is remarkably clear. This fact induced me to make an extended comparative investigation of individual and ethnic symbolism, the results of which have been recently published.[11] This complication of psychology with the problem of mythology makes it impossible for me to demonstrate to you my conception of dementia præcox. For the same reasons, I must forego the discussion of the results of psychoanalytic investigation in the domain of mythology and comparative religions. It would be impossible to do this without setting forth all the material belonging to it. The main result of these investigations is, for the moment, the knowledge of the far-reaching parallelisms between the ethnical and the individual symbolisms. From the present position of this work, we can scarcely conceive what a vast perspective may result from this comparative ethnopsychology. Through the study of mythology, the psychoanalytical knowledge of the nature of the unconscious processes we may expect to be enormously enriched and deepened.