Besides, equality is an essential condition of bad breeding also; and bad breeding is indispensable to the weeding out of the human race. When the conception of heredity took hold of the scientific imagination in the middle of last century, its devotees announced that it was a crime to marry the lunatic to the lunatic or the consumptive to the consumptive. But pray are we to try to correct our diseased stocks by infecting our healthy stocks with them? Clearly the attraction which disease has for diseased people is beneficial to the race. If two really unhealthy people get married, they will, as likely as not, have a great number of children who will all die before they reach maturity. This is a far more satisfactory arrangement than the tragedy of a union between a healthy and an unhealthy person. Though more costly than sterilization of the unhealthy, it has the enormous advantage that in the event of our notions of health and unhealth being erroneous (which to some extent they most certainly are), the error will be corrected by experience instead of confirmed by evasion. One fact must be faced resolutely, in spite of the shrieks of the romantic. There is no evidence that the best citizens are the offspring of congenial marriages, or that a conflict of temperament is not a highly important part of what breeders call crossing. On the contrary, it is quite sufficiently probable that good results may be obtained from parents who would be extremely unsuitable companions and partners, to make it certain that the experiment of mating them will sooner or later be tried purposely almost as often as it is now tried accidentally. But mating such couples must clearly not involve marrying them. In conjugation two complementary persons may supply one another's deficiencies: in the domestic partnership of marriage they only feel them and suffer from them. Thus the son of a robust, cheerful, eupeptic British country squire, with the tastes and range of his class, and of a clever, imaginative, intellectual, highly civilized Jewess, might be very superior to both his parents; but it is not likely that the Jewess would find the squire an interesting companion, or his habits, his friends, his place and mode of life congenial to her. Therefore marriage, whilst it is made an indispensable condition of mating, will delay the advent of the Superman as effectually as Property, and will be modified by the impulse towards him just as effectually.