The Second Sex (French: Le Deuxième Sexe, June 1949) is one of the best-known works of the French existentialist Simone de Beauvoir. It is a work on the treatment of women throughout history and often regarded as a major work of feminist philosophy and the starting point of second-wave feminism. Beauvoir researched and wrote the book in about 14 months. She published it in two volumes and some chapters first appeared in Les Temps moderns. The Vatican placed it on its List of Prohibited Books.