In the 21st century, the essential physiological facts of human reproduction were unchanged from the time that human beings first evolved. Men and women engaged in sexual intercourse, as a result of which women sometimes became pregnant and bore children. The development of contraception and the availability of abortion had given women some degree of control over the chance of pregnancy, but the central fact remained that sex and reproduction were fundamentally linked, at any rate for women. If sex did not necessarily lead to reproduction, there was no reproduction without sex.
Likewise, at the turn of the century, the fundamental social institutions of childrearing had not changed very much since the institution of the patriarchal family came into being at some time in prehistoric antiquity. If a woman who engaged in heterosexual sex had some prospect of thus becoming a mother, a man who did so had some prospect of becoming a father.
Now fatherhood has always been a more artificial institution than motherhood (Baber and Allen, 136). The actual fact of childbearing was, after all, uniquely female (Baber and Allen, 102). Until the development of genetic testing late in the last century, the fact of fatherhood could not be determined. It was an act of faith on a man's part to accept that a woman's child was also "his." It may well be argued that the patriarchal family itself evolved as a sort of reciprocal compromise; a man accepted some shared responsibility for a given woman and her children, in turn for a right of exclusive sexual access to that woman and a more generalized domination over her.
The rise of contraception and abortion, if it freed women of the risk of pregnancy as the price of sex, also tended to free men from their side of this bargain. This figured in the abortion controversy that raised such passions in the last decades of the twentieth century, and is constantly referred to in the literature of...