Among the means of prevention of propagation, the segregation of the defectives in different homes (such as asylums for epileptics, for feeble-minded or for deaf-mutes) would be the most humane method, but also the most unsafe (temporary escape is never impossible), and the most burdensome for society. To segregate people who are still able to support themselves and deprive society of their earning capacity represents a great economic loss to the body politic. The other quite humane method of prevention of propagation is simple sterilization. The slight operation of vasectomy, respectively salpingectomy, does not give the least inconvenience nor does it alter in the least the mental or bodily character of the operated individual. This small operation has no more effect upon the person, in regard to his potency, than an obliteration of the vas deferens in the male or of the Fallopian tube in the female; and these obliterations cause so little inconvenience that they remain, as a rule, unknown to the man or woman. They are only accidentally discovered when the patients apply for the treatment of their sterility. Hence all intelligent people who have some hereditary taint should be taught to renounce propagation by this method. Those with a neuropathic diathesis or with an alcoholic diathesis, or who show an inability to learn in school, or those in whose families are found cases of dementia praecox, maniac-depressive insanity, or those suffering from incurable inheritable diseases, such as tuberculosis, cancer, syphilis, hemophilia, color blindness, albinism, in short of such diseases that do not impair their judgment, ought to preclude themselves from parenthood by voluntarily submitting to this mild operation before marriage. Those, whose judgment is materially impaired to realize the seriousness of their propagation, such as the incurable insane, inherent epileptics, the born deaf-mutes, the idiots, imbeciles, and feeble-minded, should forcibly undergo this operation. Even the dull and idle should be deprived of the chance of propagating their kind by means of sterilization. These incompetents and degenerates furnish the material from which the ranks of the habitual criminals and prostitutes are recruited. Since we have learned that the great horde of defectives is due to unfit matings and that indolent strains arise by the mating of indolent persons, society has a right and even a duty to weed out these delinquent, defective and dependent classes by the prevention of the procreation of the various defective offspring.