Dawkins's Ultimate 747 Gambit

This argument, from p. 187 in my Kindle edition of The God Delusion (I lost my print copy, lending it to light fingered theists!) is commonly cited by philosophers and theists as particularly poor, and it certainly doesn't stand up as a syllogism:

1. One of the greatest challenges to the human intellect, over the centuries, has been to explain how the complex, improbable appearance of design in the universe arises.
2. The natural temptation is to attribute the appearance of design to actual design itself. In the case of a man-made artefact such as a watch, the designer really was an intelligent engineer. It is tempting to apply the same logic to an eye or a wing, a spider or a person.
3. The temptation 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. We need a ‘crane’, not a ‘skyhook’, for only a crane can do the business of working up gradually and plausibly from simplicity to otherwise improbable complexity.
4. The most ingenious and powerful crane so far discovered is Darwinian evolution by natural selection. Darwin and his successors have shown how living creatures, with their spectacular statistical improbability and appearance of design, have evolved by slow, gradual degrees from simple beginnings. We can now safely say that the illusion of design in living creatures is just that – an illusion.
5. We don’t yet have an equivalent crane for physics. Some kind of multiverse theory could in principle do for physics the same explanatory work as Darwinism does for biology. This kind of explanation is superficially less satisfying than the biological version of Darwinism, because it makes heavier demands on luck. But the anthropic principle entitles us to postulate far more luck than our limited human intuition is comfortable with.
6. We should not give up hope of a better crane arising in physics, something as powerful as Darwinism is for biology. But even in the absence of a strongly satisfying crane to match the biological one, the relatively weak cranes we have at present are, when abetted by the anthropic principle, self-evidently better than the self-defeating skyhook hypothesis of an intelligent designer... 

...God almost certainly doesn't exist. 

It's plainly not the sort of argument a philosopher would want to put up, but Dawkins is not writing for that audience. He's not writing another Miracle of Theism. He's addressing the ordinary person and telling us why he thinks a god is improbable. To that extent, it's always seemed fine to me. I want to explain why it has always seemed fine to me. This doesn't mean, of course, that this is what Dawkins meant, or that the concepts I discuss are entirely accurate (I'm bound to be wrong about many people's god concept, for example). It's an explanation for why it has appealed to me, to perhaps explain why it appeals to others.

Points 1 and 2 summarise how many people approach the 'god explanation'. Point 3 borrows from Daniel Dennett, and asserts that the traditional mind-first view is a problem (Dawkins makes a hidden assumption here). Points 4 to 6 explain that the evidence shows that it is false (given his hidden assumption). I think he's right on his own terms, but theists and atheists often argue past each other on this. Even many atheists get the wrong end of the stick; I think, perhaps, because they are so familiar with more sophisticated god concepts. Here, Common Sense Atheism fails to see the problem, because of the god concept they address. They use philosopher Erik Wielenberg's redrawn argument as the basis for a re-appraisal. Wielenberg's piece is right on its own terms too; it's just not how I interpreted Dawkins's words. Despite Dawkins describing the above as his 'central argument', I don't see Dawkins proposing an argument; I see him refuting an argument.

He starts the chapter by referring to Fred Hoyle's Boeing 747 argument for God:

Hoyle said that the probability of life originating on Earth is no greater than the chance that a hurricane, sweeping through a scrapyard, would have the luck to assemble a Boeing 747. Others have borrowed the metaphor to refer to the later evolution of complex living bodies, where it has a spurious plausibility.

This is the common refrain (and one I used to express): if there's no God, then how likely is all this around us? And just before that, Dawkins says:

The argument from improbability, properly deployed, comes close to proving that God does not exist. 

So, the way I've always read it, Dawkins is trying to refute an argument for theism that goes something like this:

P1 There are complex things.
P2 The existence of complex things is unlikely without ultimately a mind to explain them.
[P3 Minds are complex.]
C Therefore an ultimate mind [the most complex?] exists, and this is God.

But, Dawkins says, since your god is a complex thing, it is therefore most unlikely without another mind to explain it, per P2, so the argument is self-defeating, and invalid. Spot on, I say. This doesn't need any argument for more complex explanations, per Wielenberg; it just needs a complex explanation. This argument was basically how I thought when I believed, and, to be honest, that's what everyone I knew who believed thought too, as far as I could tell! But it doesn't work. I've bracketed P3 because this is generally a hidden assumption, and, I think, is where atheists and perhaps many 'everyday' theists differ from theists who have realised this argument is hopeless.

So, many theists have thought about this some more and deny that this is the argument; they posit something more like this:

P1 There are complex things.
P2 The existence of complex things is unlikely without ultimately a mind to explain them.
[P3 Minds are simple.]
C Therefore an ultimate mind [the most simple?] exists, and this is God.

Now the argument is valid, I think, and Dawkins’s improbability objection doesn’t apply, because the god isn't a complex thing. P2 doesn't apply to it.

For theists, P2 is supported by many arguments, such as Aquinas’s five ways, Leibniz's principle of sufficient reason, Paley's teleological argument, and so on. P3 seems to be intuited from the supposed immateriality of thoughts. Minds don't have extension in space, per Descartes, for example, so don't have parts, so are simple. For atheists, obviously, these arguments don't convince.

Furthermore, for atheists, Hume’s arguments for the preferment of natural explanations, evolution by natural selection showing the direction of development from simple organisms without minds to more complex organisms with minds, and physics also showing a move from low entropy to high, and simple universe origins, all militate against P2; and the incoherence of dualism in the light of the evidence shows P3 to be false. And this is what Dawkins is referring to in points 4 to 6, I think. So, that argument, with a different hidden assumption, isn't sound.

In the end, I think Dawkins addresses an intuitive argument for god adopted by many that is invalid. Certainly, many theists don't adopt that intuitive argument, but a revised valid argument many do adopt is not sound, because our exploration of reality shows that its premises are unlikely to be true. Dawkins fails to pull out these different assumptions, but nevertheless brings forward points that fatally damage both arguments. I think many readers see what he means, and the book's popularity certainly supports that thought.

Since these are the arguments I see Dawkins refuting in this section, it follows that other arguments that theists may want to posit need to be countered differently, so I think when he says that 'The argument... comes close to proving that God does not exist', I think he's stretching. Nevertheless, I think it's reasonable to say that the first argument, above, if taken by a theist as reason for believing, is in fact a good reason for not believing.