The mere assertion of the patient that he never indulged in unnatural practices does not count. The patient’s veracity is very questionable. All venereal troubles seem to exert an inhibitory influence upon the truth-centres. The propensity of the masturbator to conceal the truth is notorious. If such a patient claims that he has never masturbated, it is likely that he is still practising it. A special psychical element, associated with this habit, prompts the majority of patients to gross and intemperate prevarication. But even if such a “rara avis,” who has abstained from actual manusturpation, should exist, still mental erethism cannot entirely be excluded. The elicitation of a history of mental erethism is connected with great difficulty. Masturbation with these patients means only the indulgence in manual practices; the voluptuous day-dreams are considered of no account, and the peculiar type of mendacity prevents them from revealing the truth even to him, upon whom they called to consult. Hence the loss of sexual power in these patients may not have been effected by continence but, on the contrary, by continual erethism. The examination of such patients really shows, as a rule, the prostatic urethra in a state, which is usually caused by prolonged erethism. After marriage, with its regulated sexual activity and the removal of the inclination to the wild erotic fancies, the neurasthenia is soon cured, not because the patient has given up abstinence, as interpreted by the anti-abstinence advocates, but, on the contrary, because he has now become real abstemious from the excesses of mental erethism. Hence the cure of neurasthenia by marriage is no proof against sexual abstinence. The patients who seek medical advice for their neurasthenic troubles may be those who have only abstained from coition but have freely and immoderately indulged in the unnatural modes of sensualism, whence their troubles originated. The real continent individuals who avoid any kind of erotic practices remain sound and healthy and do not require medical help. Their cases remain hence unknown to the profession.