There can, however, be too few people in the world; and there is everywhere a great dearth of men and women wholly sound in mind and body, light-hearted, unselfish, industrious, persevering, intelligent, able and yet well-intentioned, peaceable, and honest. On the other hand, we have a monstrous superabundance of feeble, sickly, mentally perverted, criminally disposed, idle, treacherous, vain, crafty, covetous, passionate, capricious, and untrustworthy individuals, whose claims upon others are inexhaustible, while their own services to society are either valueless or actually harmful. While the first-mentioned class produce far more than they consume, it is appalling to think of the vast store of human energy and human life which goes to waste in sick-rooms, lunatic asylums, hospitals, and prisons. And if we look more closely we find outside these institutions, and under no restraint, a still vaster army of human sharks, who prey physically and mentally upon society, and are a burden upon the industrious community. The greater number of these useless pests owe their faults to an hereditarily defective constitution of the protoplasmic germs which brought them into being; and therefore a sound system of racial ethics demands rational selection in breeding. Equally destructive, however, are external conditions and habits of life, such as the use of alcohol, resulting as they do in paralysis of energy, confusion of the mind, and degeneration of the cells (blastophthory). * * * * * The _libido sexualis_, or sexual desire in mankind is infinitely stronger than is necessary for the reproduction of the race. Man has no breeding season; he is always ready for sexual intercourse. Although the number of women in the aggregate only slightly exceeds that of men, the male has usually an instinctive inclination to polygamy. Luther accurately estimated the normal requirements of a healthy man in the prime of life at on the average two to three sexual connections in each week; and yet this is far in excess of what is necessary for the procreation of children in a monogamous marriage. It is, moreover, well known that a man can even considerably exceed the above number without injury to his health, and there are women whose needs in this respect are actually greater than those of men. It therefore follows that the widespread artificial excitement of the sexual desire from motives of sensuality is harmful from the standpoint both of ethics and of social hygiene. We cannot, it is true, be held responsible for a natural instinct inherited from our ancestors. But we must seek to subdue this instinct as far as possible, not to excite and stimulate it by artificial means. Already there is more than enough purposeless, and therefore ethically indifferent, sexual intercourse.