As the subconscious and its processes are fundamentals both in the structure of personality and in the many mechanisms through which personality, normal and abnormal, finds expression, the first eight lectures are devoted to its exposition. Indeed, as has been said, the subconscious is not only the most important problem of psychology, it is _the_ problem. The study of its phenomena must be preliminary to that of the functioning mechanisms of both the normal mind and of those special pathological conditions—the psycho-neuroses—which modern investigators are tracing to its perversions. In a recently published article M. Bergson concludes with the following prophesy: “To explore the most sacred depths of the unconscious, to labor in what I have just called the subsoil of consciousness, that will be the principal task of psychology in the century which is opening. I do not doubt that wonderful discoveries await it there, as important perhaps as have been in the preceding centuries the discoveries of the physical and natural sciences. That at least is the promise which I make for it, that is the wish that in closing I have for it.”[2] And yet one reads and hears all sorts of contradictory statements, made by those who it is presumed should know, regarding the actuality of the subconscious. Thus one or another writer, assuming to know, states most positively that there is no such thing as the subconscious. Others, equally emphatic, postulate it as an established fact rather than a theory, or assume it as a philosophical concept or hypothesis to explain particular phenomena. One difficulty is that the term, as commonly used, has many meanings, and it has followed that different writers have assumed it with respectively different meanings. Consequently the subconscious as an actuality has been unwittingly denied when the intent has been really to deny some particular meaning or interpretation, and particular meanings have been subsumed which are only philosophical concepts.