A few months ago, the evolutionary biologist Richard Dawkins received an e-mail message from a producer at Rampant Films inviting him to be interviewed for a documentary called “Crossroads.”The film, with Ben Stein, the actor, economist and freelance columnist, as its host, is described on Rampant’s Web site as an examination of the intersection of science and religion. Dr. Dawkins was an obvious choice. An eminent scientist who teaches at Oxford Universityin England, he is also an outspoken atheist who has repeatedly likened religious faith to a mental defect.But now, Dr. Dawkins and other scientists who agreed to be interviewed...