Mary O'Brien was a feminist political philosopher who was born in Glasgow, trained as a nurse, emigrated to Canada in 1957, and taught sociology and feminist theory in Toronto until her death. She was a founding member of the (now defunct) Feminist Party of Canada.
O'Brien's most influential book was "The Politics of Reproduction", a brilliant polemic which turned Marxist materialism on its head. She started from a materialist position, but for her materialism was rooted in the biological body, not the labouring body, as Marx would have had it - or, more correctly, still the labouring body for O'Brien, but labour in the sense of giving birth, not producing objects. So, for O'Brien, materialism of necessity, and from the beginning, distinguished women from men.
For O'Brien the relations of reproduction were essential to understanding humans. (The play on Marx's terminology - relations of production - is probably too obvious to mention, but I thought I'd point it out anyway.) Most fundamental was the opposition of maternity to paternity. A woman's link to her child is obvious and involuntary, while paternity is never certain. She identified the discovery of paternity as a world historical moment of great importance which completely changed men's relations of reproduction. Suddenly, men realized they actually had something to do with reproduction after all! Yet it was still all so uncertain: Was the child actually theirs? And what was their role during the pregnancy and birth? Sitting on the sidelines is so passive, so uninvolved, so alienating. So men mediated their alienation from reproduction by appropriating women and children through the institution of marriage and by peripheralizing reproduction as private, and domestic. Marriage ensured paternity (or so men hoped, anyway), while the privatization and domestication of reproduction rendered it natural, unremarkable, given.
Familiar themes in feminist anthropology of the 1960s and 1970s.
O'Brien identified a second world historical moment of potentially equal importance: the development in the late twentieth century of technological contraception, a reproductive revolution which, though driven by a white western desire to limit population growth of non-white and working class "undesirables", nevertheless gives women the possibility of reconfiguring their relations of reproduction in revolutionary ways. Contraception, if safe, reliable, and well-distributed, could allow all women the possibility of separating sexuality from reproduction as men have always been able to do.