To what extent does our social existence determine who we are? What is the meaning of sexuality for human existence? What is the meaning of 'old age'? What is a woman? And what, for that matter, is a man? Stella Sandford explores the philosophical basis of Beauvoir's reflections on these and other questions, from her early moral period, through her post-war philosophical crisis, to the astounding polymathic studies of her mature thought. She demonstrates the persistence of the fundamental existential and ethical questions that drove Beauvoir's work and her constant revision of her own positions. With a central emphasis on Beauvoir's major work, The Second Sex, extracts are also taken from her many philosophical and political essays.