This book was originally written as a thesis of habilitation for the venia legendi in psychology at a German University. Hence, it is intended for the official philosophers of a German University (before Hitler). The author, not a member of any psychoanalytic group, appears unusually sympathetic to the edifice of psychoanalysis, and remains almost wholly free from the attitude of arrogance which university psychologists assume to belittle the genius of a man like Freud. Although Freud, himself, has acknowledged his teachers in their respective order, to wit: Gustav Theodor Fechner, Theodor Meynert, Ernst Bruecke, Josef Breuer, Dorer maintains that Freud's doctrine is not independent of doctrines which have