The difference of these two destinies, arising from the same experience, is due to the fact that one ego has experienced development while the other has not. The janitor's daughter in later years looks upon sexual intercourse as the same natural and harmless thing it had seemed in her childhood. The owner's daughter had experienced the influence of education and had recognized its claims. Thus stimulated, her ego had forged its ideals of womanly purity and lack of desire which, however, could not agree with any sexual activity; her intellectual development had made unworthy her interest in the woman's part she was to play. This higher moral and intellectual evolution of her ego was in conflict with the claims of her sexuality. I should like to consider today one more point in the development of the ego, partly because it opens wide vistas, partly because it will justify the sharp, perhaps unnatural line of division we are wont to draw between sexual and ego impulses. In estimating the several developments of ego and of libido, we must emphasize an aspect which has not frequently been appreciated heretofore. Both the ego and the libido are fundamentally heritages, abbreviated repetitions of an evolution which mankind has, in the course of long periods of time, traversed from primeval ages. The libido shows its phylogenetic origin most readily, I should say. Recall, if you please, that in one class of animals the genital apparatus is closely connected with the mouth, that in another it cannot be separated from the excretory apparatus, and in others it is attached to organs of locomotion. Of all these things you will find a most fascinating description in the valuable book of W. Bölsche. Animals portray, so to speak, all kinds of perversions which have become set as their permanent sexual organizations. In man this phylogenetic aspect is partly clouded by the circumstance that these activities, although fundamentally inherited, are achieved anew in individual development, presumably because the same conditions still prevail and still continue to exert their influence on each personality. I should say that originally they served to call forth an activity, where they now serve only as a stimulus for recollection. There is no doubt that in addition the course of development in each individual, which has been innately determined, may be disturbed or altered from without by recent influences. That power which has forced this development upon mankind, and which today maintains the identical pressure, is indeed known to us: it is the same self-denial enforced by the realities--or, given its big and actual name, _Necessity_, the struggle for existence, the ’Ανἁγχη. This has been a severe teacher, but under him we have become potent. The neurotics are those children upon whom this severity has had a bad effect--but there is risk in all education. This appreciation of the struggle of life as the moving force of development need not prejudice