Money-dealings to the religious temper of the Middle Ages were somewhat like sex-activities to that of the nineteenth century and after: they were a pity, but could be excused. Now as the condemnation of usury by canonists and moralists was based on a reading of the rôle of money afterwards displaced by another, on the rôle of capital investment, and the first was allowed to stand even when it was no longer applied to a changed economic structure, so the traditional arguments about sex are based on a reading of its function which simply does not fit in with our changed social structure. The old premise was that the primary purpose of sex was the preservation of the race. Once upon a time this was true, but not now. There is a new situation: science has enormously diminished the dangers of a pregnancy, infant-mortality, and famine; machinery supplies for a large labour-force and State welfare for the parents’ education of their children and the children's care for them; psychology enhances values in sex formerly relegated to secondary purposes; domesticity itself demands wider spacing and the standard of living for whole nations a lessened birth-rate. Let Catholic theologians then, instead of appearing evasive by the distinction they draw between contrivance and contrivances and by allowing intercourse more certainly destined to be childless than the contraception they forbid, instead of tinkering with their old apparatus and adjusting it to ‘rhythm’ and other methods which do not touch the heart of the problem, just leave it intactfor what it is worth, like the condemnation of usury, and address themselves to afresh statement adapted to modern conditions. They are not invited to preach a new morality, but to revise their arguments which appeal to reason, and to take a more balanced view of the conclusions that have been drawn from them.