Let us look back once again on the way in which we first tried to build up the picture of leaf metamorphosis. There we made use, first of all, of exact sense-perceptions to which we applied the power of memory in its function as their keeper. We then endeavoured to transform within our mind the single memory pictures (leaf forms) into one another. By doing so we applied to them the activity of mobile fantasy. In this way we actually endowed, on the one hand, objective memory, which by nature is static, with the dynamic properties of fantasy, and, on the other hand, mobile fantasy, which by nature is subjective, with the objective character of memory. Now, for the new organ of cognition arising from the union of these two polar faculties of the soul, Goethe coined the significant expression, exact sensorial fantasy.⁸ In terms of our knowledge of man's psycho-physical make-up, acquired earlier, we can say that, just as the nervous system forms the basis for memory, and the blood the basis for fantasy, so the 'exact sensorial fantasy' is based on a newly created collaboration of the two.