Mary Maime O'Brien (July 8, 1926 – October 17, 1998) was a feminist political philosopher. She taught sociology and feminist social theory in Canada until her death. She was a founding member of the Feminist Party of Canada.
Mary was born in Glasgow, Scotland, where she experienced the depression in the 1930s. After encountering the Fabian Society she was impressed by Beatrice Webb and joined the Labour Party as a teenager. She was a keen activist in the Labour Party but found her idealism shattered by the twin events of 1956: the Suez Crisis and the Soviet invasion of Hungary. However her experience as a midwife in the industrial slums of Clydeside was to provide her with a sceptical outlook which she exhibited in her later philosophical work.
She emigrated to Canada in 1957, where O'Brien first worked as a nurse and then completed graduate work in political philosophy.
O'Brien wrote The Politics of Reproduction (1981), an important book in the development of feminist political theory. Starting from a Marxist materialist position, O'Brien's purpose was to connect inextricably Marx's concept of labour to produce objects to the act of giving birth, thereby placing women central in Marxist materialism as she re-defined it. Challenging the persistent denial of women's experiences in political theorizing, O'Brien proposed the relations of reproduction as essential to understanding human social and political endeavours. O'Brien's work identified the discovery of paternity as a precursor to such patriarchal institutions as marriage and sole male rights to offspring.
O'Brien's work theorizes birth, and although her arguments have at times been dismissed as essentialist, hers is rather an integration of necessary essentialism and social constructivism. She considered her main purpose in her writing and teaching to place women's experience at the centre of fundamental political discourse.
O'Brien's project extended familiar themes in feminist anthropology of the 1960s and 1970s and extends into radical sociology and anthropology of the 1980s. In the 1990s, her work was eclipsed by feminist philosophers who criticized her work as reducing women's experiences to biological determinism, thereby reducing the range of female experience to a single biological necessity. Explaining and exploring the origins of patriarchy, and offering a heuristic for the analysis of reproductive processes – "moments" – O'Brien created a conceptual framework for understanding the reproductive process: the dialectics of reproduction. She insisted on the standpoint of women, as Marx had assumed the standpoint of the proletariat. She introduced into contemporary social and political theory the expression "malestream" in reference to traditional, mainstream political and philosophical Western thought.