This change in the conception of the character of the ideas, with no corresponding change in the conception of reality, marks the divorce of thought and reality and the rise of the epistemological problem. Let us recall that in Plato the relation between the higher and ultimate reality, as constituted by the complete and "Eternal Ideas," and the lower reality of perception, is that of archetype and ectype. Perceptions attempt to imitate and copy the ideas. Now, when the ideas are found to be changing, and when further the interpenetration of perception and conception is discovered, reality as fixed and complete must be located elsewhere. And just as in the old system it was the business of perception to imitate the "Eternal Ideas," so here it is still assumed that thought is to imitate the reality wherever now it is to be located. And as regards the matter of location, the old conception is not abandoned. The elder Plato is mighty yet. Reality must still be a completed system of fixed and eternal "things in themselves," "relations," or "noumena" of some sort which _our_ ideas, now constituted by both perception and conceptional processes, are still to "imitate," "copy," "reflect," "represent," or at least "symbolize" in some fashion. From this point on, then, thought has two functions: one, to help experience meet and reorganize into itself the results of its own past activity; the other, to reflect or represent in some sense the absolute system of reality. For a very long time the latter has continued to constitute the logical problem, the former being relegated to the realm of psychology. But this discovery of the reconstructive function of the idea and its assignment to the jurisdiction of psychology did not leave logic where it was before, nor did it lighten its task. Logic could not shut its eyes to this "psychological" character of the idea.[165] Indeed, logic had to take the idea as psychology described it, then do the best it could with it for its purpose. The embarrassment of logic by this reconstructive character of the idea even Aristotle discovered to some extent in the relation of the Platonic perceptions to the eternal ideas. He found great difficulty in getting a flowing stream of consciousness to imitate or even symbolize an eternally fixed and completed reality. And since we have discovered, in addition, that the idea is so palpably a reconstructive activity, the difficulties have not diminished.