Simone de Beauvoir's groundbreaking 1949 book The Second Sex argued that women have historically been oppressed and viewed as "the Other" in relation to men. Through historical analysis, existentialist philosophy, and psychoanalysis, de Beauvoir showed how women have been denied power and individual subjectivity. The book was highly controversial but helped launch the modern feminist movement by questioning traditional beliefs about gender roles and the social construction of femininity. It remains an important work for its original insights into how patriarchal cultural myths shape perceptions of women.