What would it be like to be privy to the mind of one of the twentieth century’s greatest thinkers? John Gerassi had just this opportunity; as a child, his mother and father were very close friends with Jean-Paul Sartre and Simone de Beauvoir, and the couple became for him like surrogate parents. Authorized by Sartre to write his biography, Gerassi conducted a long series of interviews between 1970 and 1974, which he has now edited to produce this revelatory and breathtaking portrait of one of the world’s most famous intellectuals.

Through the interviews, with both their informalities and their tensions, Sartre’s greate...