For example, Dawkins claimed that the central argument of the book goes something like this:
- One of the greatest challenges to the human intellect is to explain how the complex, improbable appearance of design in the universe arises.
- The natural temptation is to attribute the appearance of design to actual design itself, i.e. an intelligent designer.
- The temptation is a false one because the hypothesis raises the larger problem of explaining who designed the designer.
- The most ingenious explanation for the complexity of life is Darwinian evolution.
- We don't have an equivalent explanation in physics for cosmic fine-tuning.
- We should not give up hope of finding a better explanation in physics for cosmic fine-tuning.
- Therefore, God almost certainly does not exist.
As it happens, the conclusion is not only a non-sequitur but it's based on at least one premise which is patently false. Premises 1, 2, 5, and 6 are uncontroversial, and I'm willing to grant 4 just to be easy to get along with, but premise 3 is clearly erroneous.
Dawkins tries to support premise 3 by arguing that if the world's complexity requires an explanation then the designer of the world must itself be even more complex than the world it designed, and must itself require an explanation a forteriori. There are, however, at least three things wrong with this:
1. If it were concluded that a designer was the source of the complex design of the cosmos (or of living things) that conclusion stands whether we can explain the designer or not. We believed, for example, that gravity existed long before there was any explanation for it, and if some future astronauts landed on Mars and discovered there a six foot platinum cube with nearly perfect angles and facets as smooth as glass they'd certainly be justified in believing that the cube was left there by some intelligent beings even if the astronauts had no idea who they were, how they made the cube, how they got it to Mars, or how long ago they did it. None of that would be relevant to the inference that the cube was an artifact of intelligent agents.
2. Complexity is a property of physical, material things which have parts. If there is a designer of the space-time-matter universe it would transcend the universe and thus itself not be material, physical, or spatial. It would be pure, immaterial mind. Mind doesn't have parts, and Dawkins commits a category error when he argues that minds must be complex. The products of minds might be complex, but it doesn't follow that minds themselves are complex.
3. If everything needed to be explained before it could count as an explanation then nothing would ever be explained. We'd be caught in an infinite regress of explanations, none of which would be satisfactory until it, too, was explained.
I wish Prof. Dawkins well in his recovery and hope that his health fares much better in response to the ministrations of his doctors than has the central argument of The God Delusion in response to the ministrations of his philosophical critics.