One is not born, but becomes, a woman. Woman has been defined as man’s Other, not as a subject in her own right.
The longer story
'One is not born, but rather becomes, a woman.' Beauvoir's 'Second Sex' (1949) inaugurated the sex/gender distinction and analysed how women are constructed as Other to men's Subject. Her existentialist feminism—freedom achieved through struggle against objectification—influenced everything that came after. For arts research, Beauvoir's analysis of how femininity is produced through practice and expectation opens questions about how creative fields position women: as creators? As subjects? As objects? The second sex in art history is vast territory.