QUOTE : It is not a question of risking one hypothesis among others, but of introducing a new category, the category of "form," which, having its application in the inorganic as well as the organic domain, would permit bringing to light the "transverse functions" in the nervous system of which Wertheimer speaks and whose existence is confirmed by experience without a vitalist hypothesis. For the "forms," and in particular the physical systems, are defined as total processes whose properties are not the sum of those which the isolated parts would possess. More precisely they are defined as total processes which may be indiscernable from each other while their "parts," compared to each other, differ in absolute size; in other words the systems are defined as transposable wholes. We will say that there is form whenever the properties of a system are modified by every change brought about in a single one of its parts and, on the contrary, are conserved when they all change while maintaining the same relationship among themselves.