Two years ago, Stephen J. Dubner wrote a cover story for the New York Times Magazine called "Choosing My Religion." It became one of the most widely discussed articles in the magazine's history. Turbulent Souls, the book that grew out of that article, is an intimate memoir of a man in search of a Jewish heritage he never knew he had. It is also a loving portrait of his parents. Stephen Dubner's family was as Catholic as they come. His devout parents...