A tour through religion from prehistoric animism, through Shamanism and Polynesian religion to the three Abrahamic faiths. Robert Wright pulls in ideas from evolutionary theory, such as Dawkins' idea of memes, and a rather simplified version of game theory to show how human ideas of god(s) have changed over time. As other reviewers have commented, there are some large omissions, such as non-Abrahamic modern religions. Arguably Wright's treatment of Shamanism and non-Hebrew polytheistic religion is also rather superficial, but what can you expect in a book of only 500 pages? This is also true of evolution, game theory and particle physics, which Wright touches on to give support for his own ideas; if you want to learn about these theories, look elsewhere, for example Dawkins' books. When it comes to Christianity and Judaism, Wright's academic credentials shine through. He writes in an informed and balanced way that is also clear and easy to read, though sometimes a little informal for my taste. I am sure his lectures are entertaining.
And what of its contribution to the "God Delusion" debate? Religious fundamentalists are likely to throw this book down in disgust, though they should try not to. Atheists will read the book nodding in agreement with 90% of it, and are likely to learn from it, unless they have studied academic theology and know his source materials already. Wright argues that religion is not as harmful as Dawkin and Hitchens claim, but it would be possible for to concede these points whilst remaining an atheist. I think there is useful reading here for the religious liberal too, though it is tucked away in the afterword and an appendix, where Robert Wright has hidden his arguments for the existence of a real, as well as a perceived, God. Unlike the rest of the book, which is easy to follow, these arguments are condensed and abstruse -- I suspect that they are flawed, but it rather hard to tell. Please Dr Wright, could you expand these arguments into another book?