by vital processes, which is subjectively perceived as aspiration, longing and striving. We see in the diversity of natural phenomena the desire, the libido, in the most diverse applications and forms. ... Claparède in a conversation once remarked that we could as well use the term 'interest.'"
Dr. James J. Putnam, who has been alert from the first to the philosophical aspect of Freud's psychology, and has repeatedly called the attention of his colleagues to their importance, has especially noted (in his Presidential Address before the American Psychopathological Association, May, 1913) the wider affiliations of the concept as used by Jung:
"Let its name be altered, and its functions but slightly more expanded, and we have Bergson's poussée vitale, the understudy of 'self-activity.'"[1]
If the genetic surmises of Jung are substantiated,[2] we shall have made progress toward recognizing the empirical basis for a 'soul,' not alone in the sense of a result of integrative processes, but as a prior condition of such processes. It would remain, Jung thinks, as purely an hypothetical entity as physical energy. "I maintain that the conception of libido with which we are working is not only not concrete or known, but is an unknown x, a conceptual image, a token, and no more real than the energy in the conceptual world of the physicist."[3] Yet he declares also that 'in nature' the artificial distinction between hunger and the sex impulse does not exist; that here we find only a continuous 'instinct of life,' a will to live, which so far coincides with the Will of Schopenhauer. It would be difficult to reconcile these two contrasting views of the original impulse, were it not apparent that the entities with which psychology deals are 'found in nature' in two quite different ways, (a) as the materials of experience and (b) as the accompanying (and, if you like, subconscious) conditions of the movement of experience, especially for its selective character. The most general instinct, under whatever name, is found in nature, but in the second way;
