I've just re-read chapter 4 of The God Delusion, which Dawkins says "contained the central argument of my book". The chapter is called "Why there almost certainly is no God".
Just to make it easier, he summarises the argument briefly in six numbered steps at the end of the chapter. I can summarise it even more briefly, as follows: "the main argument for the existence of God is that someone must have designed all these incredible creatures we see around us. But now we know about evolution, that argument fails. So God doesn't exist."
Huh? It's just another Dawkins book about evolution? Is that it?
He seems to think that demolishing one argument for the existence of God, proves that God "almost certainly" doesn't exist. That's a logical fallacy, known as the "straw man". Refuting one argument FOR something doesn't disprove it, or even lower its probability.
Two further points:
(a) in the body of the chapter (but not in the summary) he suggests that God must be very improbable, because if you accept that the world as we see it is improbable (and I'm not at all sure what that would mean), and you invoke a designer to design it to get round the improbability, then, he says, "the designer has got to be at least as improbable" as the world he designs. That statement (in bold) is made without any justification, as far as I can see.
(b) he notices that evolution doesn't explain how the universe came to exist. But, he says (point 6), "we should not give up hope of a better [explanation] arising in physics, something as powerful as Darwinism is for biology".
"We should not give up hope" ! It's nice to see that Dawkins has faith.
(Reminder: I don't believe in God).
