Unknown author · Public domain

A descendant of Hasidic rabbinic dynasties on both sides of his family, he fled Warsaw six weeks before the German invasion in 1939 and lost his mother and three sisters in the Holocaust. Rebuilt himself as one of the century's major Jewish theologians, arguing in books like The Sabbath and God in Search of Man that religion is a response to wonder rather than a set of propositions to prove. In 1965 he marched arm in arm with Martin Luther King Jr. at Selma, and said afterward that he felt his legs were praying.