To the reader who grasps the population problem it may seem that this moral code would place society on the horns of a painful dilemma, for while morality is said to require a closer union between the sexes than has hitherto prevailed, propagation—which is the actual result of that union—must be limited to an extent hitherto unknown, and by many people deemed impossible of attainment. By its patient investigations of nature, however, science here comes to the rescue of those whose standpoint in viewing the sexual problem is one of ardent sympathy with the essential needs and the moral aspirations of man in a social position truly pathetic. Physiology has revealed that sexual organs are naturally divided into amative and reproductive organs, each class functionally distinct from the other. Amative organs relate primarily to sexual union, while reproductive organs relate primarily to impregnation and gestation. The process of reproduction may take place without use of the amative organs by simply bringing spermatozoa to ova (this has been done), and on the other hand the amative organs can be exercised without effecting reproduction. Sexual intercourse and procreation are not vitally related, as they are ordinarily assumed to be. Moreover, the instincts connected with sexual union and with offspring are separate and distinct. In popular, confused thought, a reproductive instinct is attributed to animals and man. In reality, no direct instinct to reproduce the species exists. Animals unite sexually from an instinct directed to a pleasurable exercise of function; and although, in man, the relation has been made complex by his knowledge of the facts of reproduction and of social life, the sexual instinct is connected solely with pleasure and social feeling—not with reproduction. On the other hand, instincts associated with the presence and nurture of the young are not sexual or related to sexual passion. Therefore any doctrine requiring man’s exercise of the sexual function to be restricted to the end of reproduction is without justification in nature and directly conflicts with the facts of life. The sexual act, in the natural order of things, is only occasionally in accidental relation to the reproductive process, for with married people in a thousand acts only a dozen may be reproductive. If social morality then requires the satisfaction of normal sexual feeling—and I think I have shown this to be the case—the desideratum is to prevent at will instead of leaving to accident the above occasional relation, and make the separation between amative and reproductive conditions as complete as their functional separation.