It is the common belief that one, and only one, unmentionable act is what the lovers seek as the source of their unnatural gratification, and that this produces spinal disease, epilepsy, consumption, dropsy, and the like.[3] Nothing can be more mistaken, as the scientifically reported cases of avowed and adult sinners amply demonstrate. Neither do they invariably or even usually prefer the _aversa Venus_; nor, when this happens, do they exhibit peculiar signs of suffering in health.[4] Excess in any venereal pleasure will produce diseases of nervous exhaustion and imperfect nutrition. But the indulgence of inverted sexual instincts within due limits, cannot be proved to be especially pernicious. Were it so, the Dorians and Athenians, including Sophocles, Pindar, Æschines, Epaminondas, all the Spartan kings and generals, the Theban legion, Pheidias, Plato, would have been one nation of rickety, phthisical, dropsical paralytics. The grain of truth contained in this vulgar error is that, under the prevalent laws and hostilities of modern society, the inverted passion has to be indulged furtively, spasmodically, hysterically; that the repression of it through fear and shame frequently leads to habits of self-abuse; and that its unconquerable solicitations sometimes convert it from a healthy outlet of the sexual nature into a morbid monomania.[5] It is also true that professional male prostitutes, like their female counterparts, suffer from local and constitutional disorders, as is only natural.[6] It is the common belief that boys under age are specially liable to corruption. This error need not be confuted here. Anyone who chooses to read the cases recorded by Casper-Liman, Casper in his Novellen, Krafft-Ebing, and Ulrichs, or to follow the developments of the present treatise, or to watch the manners of London after dark, will be convicted of its absurdity. Young boys are less exposed to dangers from abnormal than young girls from normal voluptuaries.