of his argument against the existence of God, the Ultimate Boeing 747 gambit, where he argues that the first attempt is self-refuting, and the second approach is the way forward. At the end of chapter 4 ("Why there almost certainly is no God"), Dawkins sums up his argument and states, "The temptation [to attribute the appearance of design to actual design itself] is a false one, because the designer hypothesis immediately raises the larger problem of who designed the designer. The whole problem we started out with was the problem of explaining statistical improbability. It is obviously no solution to postulate something even more improbable". In addition, chapter 4 asserts that the alternative to the designer hypothesis is not chance, but natural selection. Dawkins does not claim to disprove God with absolute certainty. Instead, he suggests as a general principle that simpler explanations are preferable (see Occam's razor) and that an omniscient or omnipotent God must be extremely complex (Dawkins argues that it is logically impossible for a God to be simultaneously omniscient and omnipotent). As such he argues that the theory of a universe without a God is preferable to the theory of a universe with a God. Religion and morality The second half of the book begins by exploring the roots of religion and seeking an explanation for its ubiquity across human cultures. Dawkins advocates the "theory of religion as an accidental by-product – a misfiring of something useful" as for example the mind's employment of intentional stance. Dawkins suggests that the theory of memes, and human susceptibility to religious memes in particular, can explain how religions might spread like "mind viruses" across societies. He then turns to the subject of morality, maintaining that we do not need religion to be good. Instead, our morality has a Darwinian explanation: altruistic genes, selected through the process of evolution, give people natural empathy. He asks, "would you commit murder, rape or robbery if you knew that no God existed?" He argues that very few people would answer "yes", undermining the claim that religion is needed to make us behave morally. In support of this view, he surveys the history of morality, arguing that there is a moral Zeitgeist that continually evolves in society, generally progressing toward liberalism. As it progresses, this moral consensus influences how religious leaders interpret their holy writings. Thus, Dawkins states, morality does not originate from the