Moll believes it is very doubtful whether heterosexual satiety alone can ever suffice to produce homosexuality.  Naecke was careful to set aside the cases, to which much significance was once attached, in which old men with failing sexual powers, or younger men exhausted by heterosexual debauchery, are attracted to boys.  In such cases, which include the majority of those appearing late, Naecke regarded the inversion as merely spurious, the faute de mieux of persons no longer apt for normal sexual activity.

Such cases no doubt need more careful psychological study than they usually receive.  Fere once investigated a case of this kind in which a healthy young man (though with slightly neurotic heredity on one side) practised sexual intercourse excessively between the ages of 20 and 23—­often impelled more by amour propre (or what Adler would term the “masculine protest” of the organically inferior) than sexual desire—­and then suddenly became impotent, at the same time losing all desire, but without any other loss of health.  Six months later potency slowly returned, though never to the same extent, and he married.  At the age of 35 symptoms of locomotor ataxia began to appear, and some years later he again became impotent, but without losing sexual desire.  Suddenly one day, on sitting in close contact with a young man at a table d’hote, he experienced a violent erection; he afterward found that the same thing occurred with other young men, and, though he had no psychic desire for men, he was constrained to seek such contact, and a repugnance for women and their sexuality arose.  Five months later a complete paraplegic impotence set in; and then both the homosexual tendency and the aversion to women disappeared. (Fere, L’Instinct Sexuel, p. 184.) In such a case, under the influence of disease, excessive stimulation seems to result in more or less complete sexual anesthesia, just as temporarily we may be more or less blinded by excess of light; and functional power reasserts itself under the influence of a different and normally much weaker stimulus.

Leppmann, who has studied the homosexual manifestations of previously normal old men toward boys ("Greisenalter und Kriminalitaet,” Zeitschrift fuer Psychotherapie, Bd. i, Heft 4, 1909), considers the chief factor to be a flaring up of the sexual impulse in a perverted direction in an early stage of morbid cerebral disturbance, not amounting to insanity and not involving complete irresponsibility.  In such cases, Leppmann believes, the subject may, through his lack of power, be brought back to the beginning of his sexual life and to the perhaps unconsciously homosexual attractions of that age.

With the recognition that homosexuality in youth may be due to an as yet undifferentiated sexual impulse, homosexuality in mature age to a retarded development on a congenital basis, and homosexuality in sold age