All agree in recognising the fact that females exist in the human species; today as always they make up about one half of humanity. And yet we are told that femininity is in danger; we are exhorted to be women, remain women, become women. It would appear, then, that every female human being is not necessarily a woman; to be so considered she must share in that mysterious and threatened reality known as femininity.

Introduction : Woman as Other - The Second Sex (1949)