Simone de Beauvoir
1908 CE – 1986 CE · Contemporary Era
“One is not born, but rather becomes, a woman: gender is constructed, not given.”
Biography
De Beauvoir applied existentialist philosophy to the situation of women, producing the founding text of modern feminist philosophy. She argued that throughout history, man has been defined as the Subject while woman is defined as Other, and that women must claim their freedom through authentic self-creation.
Major Works
Key Arguments
Click “Philosophy 101” to read the full exploration of each argument.
Woman as Other
De Beauvoir argued that throughout history, man has been defined as the Subject, the essential, the norm, while woman is defined as the Other, the inessential, the deviation. Liberation requires women to reject this imposed identity and create themselves.
Why it matters: The basic text of modern feminism; transformed gender theory, social philosophy, and political activism.
One Is Not Born, But Rather Becomes, a Woman
De Beauvoir argued that femininity is not a biological destiny but a social construction. From birth, girls are taught to be passive, nurturing, decorative, and self-sacrificing, not because nature demands it, she contended, but because society enforces it through education, custom, economic dependence, and the constant pressure of male expectations. In her view, there is no eternal 'feminine nature'; there are only the roles that a patriarchal society has assigned to women and called natural.
Why it matters: The single most influential sentence in feminist philosophy. De Beauvoir's distinction between biological sex and socially constructed gender became the foundation of gender studies as an academic discipline and provided the theoretical framework for second-wave feminism. Her analysis of how oppression is internalized by the oppressed anticipated later work in critical race theory and postcolonial thought.
The Ethics of Ambiguity
De Beauvoir argued that human existence is fundamentally ambiguous, we are both free and situated, both subjects and objects, both individual and social. Existentialist ethics requires that we embrace this ambiguity rather than flee from it. We must use our freedom to liberate not only ourselves but others, because in her view, genuine freedom is impossible in a world where others are oppressed. Oppressing another is a denial of the human condition we share.
Why it matters: A crucial extension of existentialism into ethics that addressed a gap left by Sartre. While Sartre emphasized bold individual freedom, de Beauvoir argued that freedom is inherently social and political, that authentic existence requires solidarity with the oppressed. This made existentialism relevant to liberation movements worldwide and remains a compelling argument that individual freedom and social justice are inseparable.
Lasting Influence
Pioneer of feminist philosophy. Influenced second-wave feminism, gender studies, and existentialist ethics. Her actual argument -- that women's apparent deficiencies are socially constructed and that genuine liberation requires the same freedom existentialism demands of men -- is a serious philosophical position that deserves to be evaluated on its own terms, distinct from the much later gender theory that claims her as a foundation while often departing from her existentialist commitments.
Your Reading Path
The Companion Guide
Seven eras of philosophy in one volume — reading lists, key terms, journal prompts · $19.99