The expression psychic energy has already been used for a long time. We already find it in Schiller, on Grot and Lipps. For
Lipps the psychic strength is the possibility that on the soul appears
processes that reach a definitive degree of effectiveness. When in action, the psychic energy manifests in the dynamic phenomena of the soul, such as the tendencies, the deviation, the will, the affection, the performance, the production of works etc., that are exactly strength psychic. When virtual, the energy appears on the acquisitions, possibilities, aptitudes, attitudes that are
conditions. The differentiation between the diverse types of energy, such as the energy of the pleasure, the energy of sensation, the energy of the contrast, etc., as the one that Lipps makes , it seems inadmissible, regarding Jung, because the specifications of the energy are, exactly, the forces and the diverse conditions. If psyche, as the psychologists of conscience want, consists only on conscientious processes we could be satisfied to claim the Psychic Energy. However, Jung says, as we know that the unconscious processes are also of the competence of the Psychology and not only of the Physiology of the brain. We need to establish our concept of energy in a little wider base. It is what Jung tries to make in this volume on Psychic Energy.