Only memory can sketch in the old features in the new picture; in reality the old materials and forms have been replaced by new ones. It is different in the case of psychic evolution. One can describe this unique state of affairs only by saying that every previous stage of development is preserved next to the following one from which it has evolved; the succession stipulates a co-existence although the material in which the whole series of changes has taken place remains the same.
The earlier psychic state may not have manifested itself for years but nevertheless continues to exist to the extent that it may some day again become the form in which psychic forces express themselves, in fact the only form, as though all subsequent developments had been annulled and made regressive. This extraordinary