Secondly, we must be clear as regards the =problem= which action, as thus defined, presents to psychology. We have, of course, _to describe and to correlate_; to describe the mental processes that occur with movement, or with one or more of its phases; and to indicate, as well as our knowledge permits, the corresponding processes in the nervous system. We have made out three modes of correlation: separate mental processes correspond with certain brain-processes; the pattern of mental connection corresponds with the play of associative tendencies in the brain; and the course of the mental stream corresponds with the activity of determining tendencies. These, then, are the limits within which we work; and we shall be obliged to leave the subject very much in the rough; for psychological description is still imperfect, and our knowledge of the nervous mechanisms is woefully incomplete. Be clear, nevertheless, that _the psychological problem lies within these limits_. The psychologist has nothing to do with the relative values of ‘motives.’ He cannot teach you how to acquire ‘control’ of your actions. His task is simply to set forth the facts; and if the facts that he discovers are of value for morals or education, as indeed they can hardly fail to be, so much the better; only, you must not confuse scientific information with practical advice, and be disappointed at the one because you do not receive the other. All this has been said before; but the present is a good time for repeating it.