between these two kinds of observation, the single and the double, the physical and the psychological, is radical and profound. The method to be pursued in studying nature, and the method to be pursued in studying man, can now no longer be regarded as the same. The physical method observes, but the psychological method swings itself higher than this, and observes observation. Thus psychology, or philosophy properly so called, commences precisely at the point where physical science ends. When the phenomena of nature have been observed and classified, the science of nature is ended. But when the phenomena of man, his feelings, intellectual, and other states, have been observed and classified, true psychology has yet to begin; we have yet to observe our observation of these phenomena, this fact constituting, in our opinion, the only true and all-comprehensive fact which the science of man has to deal with; and only after it has been taken up and faithfully observed, can philosophy be said to have commenced.
Further, the divergence which, in consequence of this distinction, takes place at their very first step, between psychological and physical science, is prodigious. In constructing the physical sciences, man occupies the position of a mere observer. It is true that his observation of the phenomena of nature is an act, and that so far he is an agent as well as an observer; but as this act belongs to himself, and as he has here no business with any phenomena except
