Originally the theory had reference only to the morbid pictures comprehended as “neurasthenia,” among which I found two types which occasionally appeared pure, and which I described as “actual neurasthenia” and “anxiety neurosis.” For it was always known that sexual moments could play a part in the causation of these forms, but they were found neither regularly effective, nor did one think of conceding to them a precedence over other etiological influences. I was above all surprised at the frequency of coarse disturbances in the vita sexualis of nervous patients. The more I was in quest of such disturbances, during which I remembered that all men conceal the truth in things sexual, and the more skilful I became in continuing the examination despite the incipient negation, the more regularly such disease-forming moments were discovered in the sexual life, until it seemed to me that they were but little short of universal. But one must from the first be prepared for similar frequent occurrences of sexual irregularities under the stress of the social relations of our society, and one could therefore remain in doubt as to what part of the deviation from the normal sexual function is to be considered as a morbid cause. I could therefore only place less value on the regular demonstration of sexual noxas than on other experiences which appeared to me to be less equivocal. It was found that the form of the malady, be it neurasthenia or anxiety neurosis, shows a constant relation to the form of the sexual injury. In the typical cases of neurasthenia we could always demonstrate masturbation or accumulated pollutions, while in anxiety neurosis we could find such factors as coitus interruptus, “frustrated excitement,” etc. The moment of insufficient discharge of the generated libido seemed to be common to both. Only after this experience, which is easy to gain and very often confirmed, had I the courage to claim for the sexual influences a prominent place in the etiology of the neurosis. It also happened that the mixed forms of neurasthenia and anxiety neurosis occurring so often, showed the admixture of the etiologies accepted for both, and that such a bipartition in the form of the manifestations of the neurosis seemed to accord well with the polar characters of sexuality (male and female).