It seems to me that the starting point of Dawkins and Dennett in their analyses of religion is not "God doesn't exist". Rather, it is "we hate religion." The reason for their animosity is a strong belief that religion is harmful and we would be better off without it. They rationalise this belief with the usual string of historical anecdotes and misconceptions that are so popular on atheist websites (such as the imaginary conflict between science and religion; religion causing wars, intolerance and suicide bombers; no atheist ever killed someone else because their atheism etc etc etc.). It all boils down to Steven Weinberg's fatuous and false sound bite "For good people to do bad things, that takes religion." Presumably he lives in a world without jealousy, revenge, money, hunger, anger, a mistaken sense of duty, scientific ignorance or stupidity.
In fact, I don't see how any consistent Darwinist could say religion is a 'bad thing'. Religion is human nature. Dennett and Dawkins both try to explain it as an unwelcome side effect of some other evolutionary adaptation. But this is highly unlikely because it is too in-built and multi-centred. Religion is caused by our brains ability to generate mystical experience; our instinctive desire for God or gods; our feeling for an objective moral order; our sense of wonder at nature and our skills at social cohesion. These traits are far too varied mean that religion is not a side-effect, it is a fundamental part of human nature. We also know religious belief is partly inheritable which further proves that speculation about memes is way off beam.
If religion is fundamental to our nature then, according to Darwinists, it can only have arisen in one way - selected by evolution. And it would only be selected if it was advantageous. The inherent propensity towards religion, that everyone bar a few mutants have, must be an adaptation that helped human beings dominate the planet. Furthermore, about the only working definition of 'good' and 'bad' that a Darwinist can get a handle on is whether or not a behavior has helped humans survive and multiply. Religion must, by Darwinian lights, be a 'good thing'.
It is just that like many other good things, it can go wrong.
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