Known typically for her association with Jean Paul Sartre, Simone de Beauvoir exerted an enduring influence upon modern day feminism. "One is not born, but rather becomes a woman" is the primal theme in The Second Sex. Some may not deem her a major philosopher, but to humanists, socialists and Marxists, she is an original thinker. Philippe Knab deduces that in the Second Sex, “firstly, she put forward a series of empirical claims about women as the Other, that is, about what the role gender played in her society. Secondly, she puts forward a philosophical argument for why sexism is wrong. Clearly, the validity of the empirical part of the argument depends on one's historical cultural background.