Ronald Aronson is the author of “Camus and Sartre: The Story of a Friendship and the Quarrel That Ended It.” Aronson recounts for Steve Paulson the relationship and the very public dispute between two of the twentieth century’s leading intellectuals. Though both men of the left, they eventually fell out over the issue of political violence and support of the Soviet Union. Their argument was never really settled and we are still living with its consequences.