A preeminent scientist -- and the world's most prominent atheist -- asserts the irrationality of belief in God and the grievous harm religion has inflicted on society, from the Crusades to 9/11.With rigor and wit, Dawkins examines God in all his forms, from the sex-obsessed tyrant of the Old Testament to the more benign (but still illogical) Celestial Watchmaker favored by some Enlightenment thinkers. He eviscerates the major arguments for religion and demonstrates the supreme improbability of a supreme being.