From cases of this kind, depending on cerebral causes, there must be distinguished others where the absence of function arises from an absence or malformation of the generative organs, as in certain hermaphrodites, idiots, and cretins. A case belonging here is found in Maschka’s hand-book.
Case 10. Complainant pleads for divorce on account of impotence of her husband, who has never had intercourse with her. She is thirty-one years old, and a virgin. The husband is somewhat weak mentally, physically strong; the genitals well developed. He declares that he has never had a complete erection or a flow of semen, and says that he is totally indifferent about intercourse with women.
Ultzmann’s[[38]] observations show that anæsthesia sexualis is not caused by aspermia simply. He shows that even in congenital aspermia the vita sexualis and sexual power may be entirely satisfying; an additional proof that defective libido ab origine is to be sought for in cerebral conditions.
The naturæ frigidas of Zacchias are examples of a milder form of anæsthesia. They are met more frequently among women than among men. The characteristic signs of this anomaly are: slight inclination to sexual intercourse, or pronounced disinclination to coitus without sexual equivalent, and failure of corresponding psychical, pleasurable excitation during coitus, which is indulged in simply from sense of duty. I have often had occasion to hear complaints from husbands about this. In such cases the wives have always proved to be neuropathic ab origine. Some were at the same time hysterical.
2. Acquired Anæsthesia.
Acquired diminution of sexual instinct, extending through all degrees to extinction, may depend on various causes. These may be organic and functional, psychical and somatic, central and peripheral. The diminution of libido, as age advances, and its temporary disappearance after the sexual act, are physiological. The variations with reference to the duration of the sexual instinct are dependent upon individual factors. Education and manner of life have a great influence upon the intensity of the vita sexualis. Intense mental activity (hard study), physical exertion, emotional depression, and sexual continence decidedly diminish sexual inclination. Continence at first induces increase, but sooner or later, according to constitutional conditions, the activity of the generative organs decreases, and with it libido. At all events, in a person sexually mature, a close connection exists between the activity of the generative glands and the degree of libido. That this relation is not determinate is shown by the cases of sensual women, who, after the climacterium, continue to have sexual intercourse, and may manifest states of sexual excitement (cerebral). Also in eunuchs it is seen that libido may long outlast the production of semen.
On the other hand, however, experience teaches that libido is essentially conditioned by the function of the generative glands, and that the facts mentioned are exceptional manifestations. As peripheral causes of diminution or extinction of libido, may be mentioned castration, degeneration of the sexual glands, marasmus, sexual excesses in the form of coitus and masturbation, and alcoholism [cocainism]. In the same way, the disappearance of libido in general disturbances of nutrition (diabetes, morphinism, etc.) may be explained. Finally, the atrophy of the testicles should be remembered, which has sometimes been observed to follow focal lesions of the brain (cerebellum).
A diminution of the vita sexualis, from degeneration of the tracts of the cord and genito-spinal centre, occurs in diseases of the spinal cord and brain. A central interference with the sexual instinct may be organically induced by cortical disease (dementia paralytica in its advanced stages); functionally, by hysteria (central anæsthesia?) and emotional insanity (melancholia, hypochondria).
C. Hyperæsthesia (Abnormally Increased Sexual Desire).
Pathology has no easy task, in the single case, when it has to decide whether the impulse to sexual satisfaction has reached a pathological degree. Emminghaus (“Psychopathologie,” p. 225) declares that the immediate re-awakening of desire after satisfaction, with its occupation of the entire attention, and no less the excitation of libido by the sight of persons and things which in themselves should have but an indifferent sexual effect, are decidedly abnormal. In general, sexual instinct and its corresponding needs are in proportion to physical strength and age. Sexual desire rapidly increases after puberty, until it reaches a marked degree; is strongest from the twentieth to the fortieth year, and then slowly decreases. Married life seems to preserve and control the instinct. Sexual intercourse with many persons increases the desire.