How does Dawkins' argument for God’s massive improbability run? In the fourth chapter of The God Delusion, entitled “Why There Almost Certainly is No God,” Dawkins spends almost fifty pages explaining the argument. Put briefly, Dawkins claims that a Creator-God would have to be extremely complex, in fact the most complex thing in the universe. But since we have no plausible way of understanding how such a complex entity could exist, it is highly improbable that He actually does exist. The Boeing 747 reference allegedly comes from Fred Hoyle, and here I will let Dawkins explain, “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.” (113) Dawkins’ contention is that we do have a plausible explanation for the improbability of biological life in natural selection, but we have no equally plausible explanation for the existence of God, who would have to be more complex than His creation. Thus God is the “ultimate” 747. Interlaced with this claim is a collection of discussions of such issues as the improbability of biological complexity, the Darwinian picture of how biological life (however improbable) actually came to exist unaided by any supernatural abettors, and current models from theoretical physics on how the universe might have received its start without God’s help, just to name a few. Luckily for us, however, in the final three pages he comes very close to laying out the argument formally, even going so far as to include what look like logical steps. Here is how he puts it:

(1) One of the greatest challenges to the human intellect, over the centuries, has been to explain how the complex, improbable appearance of design 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 for 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. (157-158)

When put this way the argument covers a lot of ground and involves quite a bit of digestion, but it still seems fairly straightforward. However, difficulties arise almost as soon as we begin to try to clarify the argument. The first problem hits us almost immediately: what, exactly, is Dawkins arguing against? On the surface he seems to be claiming that his argument is aimed at defeating the following proposition:

(G) God exists.

As formulated above, however, it seems equally likely that Dawkins thinks his argument defeats this proposition:

(D) Postulating the existence of an intelligent designer is required to explain the existence of highly complex (and thus highly improbable) entities such as human beings.

In other words, on one hand it seems that Dawkins is simply arguing against the existence of God, but on the other it seems that he is arguing against the reasoning process used in certain design arguments for God’s existence.

This distinction is not insignificant. Any argument for the negation of (G) is going to be pretty clearly distinct from any argument for the negation of (D). Certainly (G) and (D) are often used in relation to one another in arguments for God’s existence, where (G) is the conclusion to the argument and (D) is one of the premises, but it just isn't the case that they are necessarily related. That is, the theist who accepts (G) is not required also to accept (D) in support of (G), and indeed there are many who don’t. Twentieth century Christian thought, for example, included multiple movements that either totally repudiated the use of logical arguments to show God’s existence or, at least, frowned on the use of logical arguments in any way that was foundational for theistic belief . Thus if Dawkins means his argument to show that (G) is false by way of the falsity of (D), there are many theists (among them some of the most influential Christian philosophers working today) to which the argument simply wouldn’t apply, as they don’t see arguments for God’s existence as being crucial for the justification of Christian belief.

The above discussion shows that we need to clarify Dawkins’ argument so we can get a better grasp of what he is trying to say. This is not an easy task. For purposes that will become clear in later posts, I want to postulate three different versions of the 747 Argument. I will call these the metaphysical, the epistemological, and the simple versions of the 747 Argument, but those formulations must be saved for future posts.


Previous posts on The God Delusion:

• Richard Dawkins' non-argument against arguments from religious experience