Within the last thirty years we have evolved a new science, the science of psychology. A generation ago psychology was subject-matter only for the philosopher, the metaphysician, the poet, or the ecclesiastic; now it is being investigated in the laboratory by tests of sensibility, reaction-times, and other responses to stimulation too technical to be explained here, tests carried out by means of elaborate and intricate instruments and machinery designed to weigh the _hidden springs of life_ in the balance. The phrase I have italicised is purposely vague, for I have no wish to fall foul of a terminology or to make any _a priori_ assumption which might involve me in controversial matters completely outside my province. At the same time I see clearly that some convenient phrase will become necessary, and I will therefore adopt one which is at least familiar and within certain limits descriptive enough, namely, the “subconscious self.” It may seem strange that one should look to any such formally organised science as modern psychology, to a science that is working in a laboratory with mechanical appliances, for any elucidation of a question which has for so long been regarded as strictly within the domain of the priest. But science, as Tyndall said, is only another name for common-sense, and a little consideration will show that the postulate I have insisted upon, namely, the growth and progress of intellectual control, demands that this admirable quality of common-sense or reason, should be applied to the elucidation of this all-important problem. Unhappily, psychology, from which we hope so much, is as yet in its infancy, and the few attempts that have been made, such as those of the late Professor Münsterberg, to apply the theories of the laboratory and the class room to the practical work of the world, cannot be said to have produced any results worth considering. In any case I must transcend the present limits of academic psychology in this consideration of the subconscious. The concepts which have grown up round this term, the “subconscious self,” are in many cases curiously concrete in form. Much error has sprung from that earnest and well-intentioned work of the late F. W. H. Myers, _Human Personality and Its Survival After Bodily Death_. Mr. Myers pictured an entity within an entity, and his work, though inductive in form, was _a priori_ in method, for he had formed the conception of a subjective personality taking shape within an objective, material shell, and had controlled his evidence to a definite, preconceived end.