The task of a theory of libido of neurotic and psychotic disturbances would have for its object to express in terms of the libido-economy all observed phenomena and disclosed processes. It is easy to divine that the greater significance would attach thereby to the destinies of the ego-libido, especially where it would be the question of explaining the deeper psychotic disturbances. The difficulty then lies in the fact that the means of our investigation, psychoanalysis, at present gives us definite information only concerning the transformation of the object-libido, but cannot distinguish without further study the ego-libido from the other effective energies in the ego.[3] DIFFERENTIATION BETWEEN MAN AND WOMAN It is known that the sharp differentiation of the male and female character originates at puberty, and it is the resulting difference which, more than any other factor, decisively influences the later development of personality. To be sure, the male and female dispositions are easily recognizable even in infantile life; thus the development of sexual inhibitions (shame, loathing, sympathy, etc.) ensues earlier and with less resistance in the little girl than in the little boy. The tendency to sexual repression certainly seems much greater, and where partial impulses of sexuality are noticed they show a preference for the passive form. But, the autoerotic activity of the erogenous zones is the same in both sexes, and it is this agreement that removes the possibility of a sex differentiation in childhood as it appears after puberty. In respect to the autoerotic and masturbatic sexual manifestations, it may be asserted that the sexuality of the little girl has entirely a male character. Indeed, if one could give a more definite content to the terms "masculine and feminine," one might advance the opinion that _the libido is regularly and lawfully of a masculine nature, whether in the man or in the woman; and if we consider its object, this may be either the man or the woman_.[4] Since becoming acquainted with the aspect of bisexuality I hold this factor as here decisive, and I believe that without taking into account the factor of bisexuality it will hardly be possible to understand the actually observed sexual manifestations in man and woman.