The first difficulty arises with the conception of sexuality. If we take sexuality as meaning the fully-developed function, we must confine this phenomenon to maturity, and then, of course, we have no right to speak of sexuality in childhood. If we so limit our conception, then we are confronted again with new and much greater difficulties. The question arises, how then must we denominate all those correlated biological phenomena pertaining to the sexual functions sensu strictiori, as, for instance, pregnancy, childbirth, natural selection, protection of the offspring, etc. It seems to me that all this belongs to the conception of sexuality as well, although a very distinguished colleague did once say, “Childbirth is not a sexual act.” But if these things do pertain to this concept of sexuality, then there must also belong innumerable psychological phenomena. For we know that an incredible number of the pure psychological functions are connected with this sphere. I shall only mention the extraordinary importance of phantasy in the preparation for the sexual function. Thus we arrive rather at a biological conception of sexuality, which includes both a series of psychological phenomena as well as a series of physiological functions. If we might be allowed to make use of an old but practical classification, we might identify sexuality with the so-called instinct of the preservation of the species, as opposed in some way to the instinct of self-preservation. Looking at sexuality from this point of view, we shall not be astonished to find that the root of the instinct of race-preservation, so extraordinarily important in nature, goes much deeper than the limited conception of sexuality would ever allow. Only the more or less grown-up cat actually catches mice, but the kitten plays at least as if it were catching mice. The young dog’s playful indications of attempts at cohabitation begin long before puberty. We have a right to suppose that mankind is no exception to this rule, although we do not notice similar things on the surface in our well brought-up children. Investigation of the children of the lower classes proves that they are no exceptions to the biological rule. It is of course infinitely more probable that this most important instinct, that of the preservation of the race, is already nascent in the earliest childhood, than that it falls at one swoop from heaven, full-fledged, at the age of puberty. The sexual organs also develop long before the slightest sign of their future function can be noticed. Where the psychoanalytic school speaks of sexuality, this wider conception of its function must be linked to it, and we do not mean simply that physical sensation and function generally designated by the term sexual. It might be said that, in order to avoid any misunderstanding on this point, the term sexuality should not be given to these preparatory phenomena in childhood. This demand is surely