Published on the occasion of Sartre’s Centenary, this book helps to understand the man behind the work, offering a psycho-social analysis of Jean-Paul Sartre with an emphasis on his masculinity. It sets out to contextualize Sartre in terms of his psycho-sexual formation and processes of self-constitution in view of his childhood. The main period under detailed study is 1905-1945, before Sartre became the Sartre. It concentrates on his early childhood, his teenage years in La Rochelle, the years at the Ecole Normale, and the first few years of his adulthood, with specific attention on the war years. An analysis of Sartre’s relationships follows, with Simone de Beauvoir and other women and men (including love and sex), before a postscript covering the period 1973-1980. This essay is not a reductive account. It tells the story of Jean-Paul Sartre, from the inside out, so that the achievements of one of the major intellectuals of the 20th Century can be measured against his own internal struggles.