Shulamith Firestone (_The Dialectic of Sex_) argues that women and men are not really very different. Firestone states (in stronger terminology than Beauvoir) that the biology of women determines their 'sex class' which is embedded in family where women and children are at mercy of men. Biologically reproductive differences lead to sexual divisions of labor.
SF looks to new technologies (that are more extensive than anything anticipated by Beauvoir) for liberation from 'curse of Eve.' Artificial insemination, test-tube babies, and domestic cybernetics will emancipate women (and children) from their biology. She asserts that with advances in medical science possibility exists for males to carry fetus in implanted wombs and eventually lactate. Gender and sex will become redundant in androgynous, unisex future. In arguing for androgynous equality and a world of cybernetic communism where all humans participate in child-bearing and child-rearing, Firestone (criticized for being techno-utopian) wants to destroy political uses of difference (which reappeared as virtue a few years after _DofS_ was published). Michael Hoover