Important forces are, however, at work in the contrary direction. If the growing prevalence of herd morality will tend to place a new emphasis on the importance of uniformity, uniformity in the moral sphere is likely to prove more difficult of attainment. Two factors in particular will militate against it. These are the growth of economic independence among women, and the practice of birth control. Let us consider these factors separately. I. The basis of the institution of marriage is economic. Theological factors have of course played their part. The early Christian fathers, expecting the immediate end of the world, saw no reason to take steps to ensure the continuance of the race. The Christian hostility to the pleasures of the senses was, therefore, allowed to rage unchecked, and sexual intercourse was denounced as both wicked and unnecessary. As time passed, however, it was found that the world showed no signs of coming to an end, an inconsiderateness which led to the necessity for a change of attitude. The Church met the situation with a complete _volte face_. It had previously stigmatized the sexual passions as so wicked that no Christian should be permitted to indulge them: it now pronounced them to be so sacred that no Christian should be permitted to indulge them without the sanction of the Church. The sanction of the Church was given in marriage, a device whereby the Fathers sought to control and to regulate the workings of a passion they were unable to ignore. Since then the Church has claimed both the ability and the right to sanctify sex, and has looked with disfavour upon marriages consummated by the State as an infringement of her monopoly. But the fact that marriage has been instituted by God and cornered by the Church is not sufficient to account for its existence before the Christian epoch or its stability since. These rest upon an economic foundation. Throughout the recorded history of civilization the only recognized way for a woman to make her living has been through her body. Her body being her one saleable asset, she could employ it in either of two ways. She could sell the use of it to one man for an indefinite period, or she could lease it to a number of men for short and strictly regulated periods. The first method is known as marriage; the second as prostitution. The existence of these two, and of only these two, ways of gaining an economic livelihood has led to the formation of two unofficial women’s Trade Unions, the Trade Union of wives and the Trade Union of prostitutes. The strength of these unions is directly proportional to their monopoly of the economic field, and far exceeds that of any recognized Union in the more strictly industrial sphere.