In my opinion, a large measure of the obscurities and dissensions which prevail as to the nature of concepts, arises from the fact that the rôle of unconscious activity has for centuries been misunderstood or forgotten,—psychology having confined itself exclusively to consciousness: and while its action is universally admitted to-day for all other manifestations of mental life—instincts, percepts, feelings, volition, etc.—it is still excluded from the domain of concepts. The whole of the foregoing discussion is an essay towards its reintegration. Need we add that the opinion adopted as to the nature of the unconscious matters little in the present connexion? On this point there are, we know, two principal hypotheses. According to the one it is a purely physiological event, and can be reduced to unconscious cerebration. According to the other, the unconscious is still a psychical fact; whether it be an affective rather than a representative state, or a complex of little, scattered consciousnesses, isolated, evanescent, with no linkage to the self, or, again, an organisation or sequence of states, which forms another current coexistent with that of clear consciousness. These theories, and others which I omit, have nothing to do with our purpose. It is sufficient to recognise unconscious activity as a fact, without any explanation, and this position would seem to be incontestable. We have seen that abstraction, in proportion as it ascends and strengthens, separates itself more and more from the image, until finally, at the moment of pure symbolism, the separation becomes antagonism. This is because there is fundamentally, and from the outset, an opposition of nature and procedure between the two. The ideal of the image is an ever-growing complexity, the ideal of abstraction an ever-growing simplification, since the one is formed by addition, the other by subtraction. To the man who is gifted with a rich internal vision, the shape of people, of monuments, of landscapes, surges up clearly and well defined: under the influence of attention, and with time, details are added,—the representation completes itself, and approaches more and more completely to the reality. So too with internal audition: witness the musician who hears ideally every detail of a symphony. The contrary holds for abstraction. “There is,” says Cournot, “an analysis which separates objects, and an analysis which distinguishes without isolating them. The use of the refracting prism is an instance of the analysis which separates or isolates. If, instead of isolating the rays so as to cause them to describe different trajectories, they are made to traverse certain media which have the property of extinguishing a definite color, we are able to distinguish without isolating.”[87]