I am under the impression that I did not succeed in convincing you of the significance of perversions for our conception of sexuality. I should therefore like to clarify and add as much as I can. It was not only perversions that necessitated an alteration of our conception of sexuality, which aroused such vehement contradiction. The study of infantile sexuality did a great deal more along that line, and its close correspondence to the perversions became decisive for us. But the origin of the expressions of infantile sexuality, unmistakable as they are in later years of childhood, seem to be lost in obscurity. Those who disregard the history of evolution and analytic coherence, will dispute the potency of the sexual factor and will infer the agency of generalized forces. Do not forget that as yet we have no generally acknowledged criterion for identifying the sexual nature of an occurrence, unless we assume that we can find it in a relation to the functions of reproduction, and this we must reject as too narrow. The biological criteria, such as the periodicities of twenty-three and twenty-eight days, suggested by W. Fliess, are by no means established; the specific chemical nature which we can possibly assume for sexual occurrences is still to be discovered. The sexual perversions of adults, on the other hand, are tangible and unambiguous. As their generally accepted nomenclature shows, they are undoubtedly sexual in character; whether we designate them as signs of degeneration, or otherwise, no one has yet had the courage to place them outside the phenomena of sex. They alone justify the assertion that sexuality and reproduction are not coincident, for it is clear that all of them disavow the goal of reproduction. This brings me to an interesting parallel. While "conscious" and "psychic" were generally considered to be identical, we had to make an essay to widen our conception of the "psychic" to recognize as psychic something that was not conscious. Analogously, when "sexual" and "related to reproduction" (or, in shorter form, "genital") has been generally considered identical, psychoanalysis must admit as "sexual" such things as are not "genital," things which have nothing to do with reproduction. It is only a formal analogy, but it does not lack a deeper basis. But if the existence of sexual perversions is such a compelling argument, why has it not long ago had its effect, and settled the question? I really am unable to say. It appears to be because the sexual perversions are subject to a peculiar ban that extends even into theory, and stands in the way of their scientific appreciation. It seems as if no one could forget that they are not only revolting, but even unnatural, dangerous; as if they had a seductive influence and that at bottom one had to stifle a secret envy of those who enjoyed them. As the count who passes judgment in the famous Tannhauser parody admits: