Nazi Germany produced an unusual group of Christian martyrs--among them, the nun philosopher Edith Stein, the mystical philosopher Simone Weil, and the peasant conscientious objector Hans JSgerstatter--but perhaps none so complex as the Lutheran theologian Dietrich Bonhoeffer. Born into a large upper-middle-class, professional family that was not particularly devout or observant (his father was one of the leading psychiatrists in Germany), Dietrich early in life decided he wanted to be a Christian theologian. Yet his family background and connections insured that he wouldn't be one in the...