My purpose in writing on this subject—No desire to lessen responsibility—The great difficulties of such an inquiry—A return to the question considered in the previous chapters on marriage—Some women and men unsuited for monogamous marriage and the duties of parenthood—The evils that must arise when those unfitted for true monogamy are forced to live under its cover—Sex subjects usually viewed either with false sentiment or with vulgarity—Shameful concealments and sniggering do not lead to true chastity—These bad conditions exert more influence on men than on women—Celibacy as unnatural and harmful in women as in men—One form of union can never be imposed for every one—Is secrecy advantageous to society—Effect of economic conditions and pressure of opinion—Without some change prostitution and the degradation of the more honourable partnerships outside marriage must be accepted—The position of the mother must always be secured—The war has caused increased independence of women—The war as well will cause a shortage of men and probably a period of poverty—These must act as further causes of avoidance of marriage—At the same time the nation will have an increased need for children—More than one form of sexual association required—The highest types of men and women should live in monogamous marriage—For others the sterile temporary union—The law should establish contracts providing for the woman in such relationships—Advantages of this procedure—Increase not hinder morality.