In the sphere of sexuality, libido does take that form whose enormous importance justifies us in the choice of the term “libido,” in its strict sexual sense. Here for the first time libido appears in the form of an undifferentiated sexual primitive power, as an energy of growth, clearly forcing the individual towards division, budding, etc. The clearest separation of the two forms of libido is found among those animals where the stage of nutrition is separated by the pupa stage from the stage of sexuality. Out of this sexual primitive power, through which one small creature produces millions of eggs and sperm, derivatives have been developed by extraordinary restriction of fecundity, the functions of which are maintained by a special differentiated libido. This differentiated libido is henceforth _desexualized_, for it is dissociated from its original function of producing eggs and sperm, nor is there any possibility of restoring it to its original function. The whole process of development consists in the increasing absorption of the libido which only created, originally, products of generation in the secondary functions of attraction, and protection of offspring. This development presupposes a quite different and much more complicated relationship to reality, a true function of reality which is functionally inseparable from the needs of reproduction. Thus the altered mode of reproduction involves a correspondingly increased adaptation to reality. This, of course, does not imply that the function of reality is exclusively due to differentiation in reproduction. I am aware that a large part of the instinct of nutrition is connected with it. Thus we arrive at an insight into certain primitive conditions of the function of reality. It would be fundamentally wrong to pretend that the compelling source is still a sexual one. It _was_ largely a sexual one originally. The process of absorption of the primitive libido into secondary functions certainly always took place in the form of so-called affluxes of sexual libido (“libidinöse Zuschüsse”). That is to say, sexuality was diverted from its original destination, a definite quantity was used up in the mechanisms of mutual attraction and of protection of offspring. This transference of sexual libido from the sexual sphere to associated functions is still taking place (_e. g._, modern neo-Malthusianism is the artificial continuation of the natural tendency). We call this process _sublimation_, when this operation occurs without injury to the adaptation of the individual; we call it _repression_—when the attempt fails. From the descriptive standpoint psychoanalysis accepts the multiplicity of instincts, and, among them, the instinct of sexuality as a special phenomenon, moreover, it recognizes certain affluxes of the libido to asexual instincts.