(A) "Sexual feeling and sexual instinct," he begins, "remain latent, except in obscure foreshadowings and impulses, until the time when the organs of procreation come to be developed. During the period of latency, when sex has not arrived at consciousness, is only potentially existent, and has no powerful organic bias, influences may operate, injurious to its normal and natural evolution. In that case the germinating sexual sensibility runs a risk of being both qualitatively and quantitatively impaired, and under certain circumstances may even be perverted into a false channel. Tarnowsky has already published this experience. I can thoroughly confirm it, and am prepared to define the conditions of this acquired, or, in other words, this cultivated perversion of the sexual instinct in the following terms. The fundamental or ground predisposition is a neuropathic hereditary bias. The exciting or efficient cause is sexual abuse, and more particularly onanism. The etiological centre of gravity has to be sought in hereditary disease; _and I think it is questionable whether an untainted individual is capable of homosexual feelings at all_."[22]
Krafft-Ebing's theory seems then to be that all cases of acquired sexual inversion may be ascribed in the first place to morbid predispositions inherited by the patient (_Belastung_), and in the second place to onanism as the exciting cause of the latent neuropathic ailment.
He excludes the hypothesis of a physiological and healthy deflection from the normal rule of sex. "I think it questionable," he says, "whether the untainted individual (_das unbelastete Individuum_) is capable of homosexual feelings at all." The importance of this sentence will be apparent when we come to deal with Krafft-Ebing's account of congenital sexual inversion, which he establishes upon a large induction of cases observed in his own practice.
For the present we have the right to assume that Krafft-Ebing regards sexual inversion, whether "acquired" or "congenital," as a form of inherited neuropathy (_Belastung_). In cases where it seems to be "acquired," he lays stress upon the habit of self-pollution.
This is how he states his theory of onanism as an exciting cause of inherited neuropathy, resulting in sexual inversion. The habit of self-abuse prepares the patient for abnormal appetites by weakening his nervous force, degrading his sexual imagination, and inducing hyper-sensibility in his sexual apparatus. Partial impotence is not unfrequently exhibited. In consequence of this sophistication of his nature, the victim of inherited neuropathy and onanism feels shy with women, and finds it convenient to frequent persons of his own sex. In other words, it is supposed to be easier for an individual thus broken down at the centres of his life to defy the law and to demand sexual gratification from men than to consort with venal women in a brothel.