Suppose we land on an alien planet orbiting a distant star and discover some machine-like objects that look and work just like a 1941 Allis Chalmers tractor; our leader says “there must be intelligent beings on this planet—look at those tractors.” A sophomore philosophy student on the expedition objects: “Hey, hold on a minute! You have explained nothing at all! Any intelligent life that designed those tractors would have to be at least as complex as they are!” No doubt we’d tell him a little learning is a dangerous thing and advise him to take the next rocket ship home and enroll in another philosophy course or two.
The point is that the leader was not trying to give an ultimate explanation of organized complexity. He was only trying to explain one particular manifestation of it—the tractors. In this context it is perfectly reasonable to explain one manifestation of organized complexity with another. Similarly theists are not trying to give an ultimate explanation for all organized complexity (including God) when they invoke God as an explanation for organized complexity.
Alvin Plantinga's response to the "who created God?" Argument used by Dawkins:
"Design doesn’t explain organized complexity (says Dawkins); it presupposes it, because the designer would have to be as complex as what it creates (designs). Perhaps, therefore, Dawkins means to argue along the following lines: there are really just two explanations of life: unguided Darwinism and an explanation, guided Darwinism, perhaps, that involves design. But the latter is really no explanation at all. Therefore the only candidate is the former.
Here there are two problems. First, this argument doesn’t depend on the facts of biology; it is substantially independent of the latter. Is it likely that Dawkins would be offering an argument of that sort? If so, why would he claim that it is “the Evidence of Evolution” that “Reveals a World Without Design”?
Set that problem aside for the moment; there is another and deeper problem with this argument. Suppose we land on an alien planet orbiting a distant star and discover some machine-like objects that look and work just like a 1941 Allis Chalmers tractor; our leader says “there must be intelligent beings on this planet—look at those tractors.” A sophomore philosophy student on the expedition objects: “Hey, hold on a minute! You have explained nothing at all! Any intelligent life that designed those tractors would have to be at least as complex as they are!” No doubt we’d tell him a little learning is a dangerous thing and advise him to take the next rocket ship home and enroll in another philosophy course or two. For of course it is perfectly sensible, in that context, to explain the existence of those tractors in terms of intelligent life, even though (as we can concede for present purposes) that intelligent life would have to be at least as complex as the tractors. The point is we aren’t trying to give an ultimate explanation of organized complexity, and we aren’t trying to explain organized complexity in general; we are only trying to explain one particular manifestation of it (those tractors). And (unless you are trying to give an ultimate explanation of organized complexity) it is perfectly proper to explain one manifestation of organized complexity in terms of another. Hence it is not the case, contra Dawkins, that an explanation in terms of divine design is a nonstarter. Such an explanation doesn’t constitute an ultimate explanation of organized complexity (if God is complex, nothing could constitute such an explanation); but it is none the worse for that.
A second point: Dawkins argues that “the main thing we want to explain” is “organized complexity.” He goes on to say that “the one thing that makes evolution such a neat theory is that it explains how organized complexity can arise out of primeval simplicity,” and he faults theism for being unable to explain organized complexity. Now first, in biology we are attempting to describe and explain terrestrial life, not organized complexity generally. And second: mind would be an outstanding example of organized complexity, according to Dawkins. Of course it is uncontroversial that if there is such a person as God, he would be a being who thinks and knows; so suppose we take Dawkins to be complaining that theism doesn’t offer an explanation of mind. It is perfectly obvious that theists won’t be able to give an explanation of mind in general—they won’t be able to offer an explanation for the state of affairs consisting in there being at least one mind— because, naturally enough, there isn’t any explanation of the existence of God. But that is certainly not a point against theism. Explanations come to an end; for theism they come to an end in God. For any other view of the same level of generality they also come to an end. The materialist or physicalist, for example, doesn’t have an explanation for the existence of elementary particles or, more generally, contingent physical or material beings; that there are some is, from that perspective, a brute fact. It isn’t easy to say precisely what counts as begging the question; but to fault theism for failing to have an ultimate explanation of mind is as good a candidate as any.
Here is a second attempt to reconstrue Dawkins’s argument.32 In The God Delusion he argues that the existence of God is monumentally improbable—about as probable as the assembly of a flight-worthy Boeing 747 by a hurricane roaring through a junkyard. Now it is not monumentally improbable, he says, that life should have developed by way of unguided Darwinism. In fact the probability that the stunning complexity of life came to be in that fashion is greater than the probability that there is such a person as God. An explanation involving divine design, therefore, is less probable than the explanation in terms of unguided Darwinism; therefore we should prefer unguided Darwinism to an explanation involving design; but these two are the only viable candidates here; therefore by an inference to the best explanation, we should accept unguided Darwinism.
Clearly a host of considerations clamor for attention here. Concede, for the moment, that unguided Darwinism is more probable than an explanation involving design; does it follow that the former is to be preferred to the latter? There is more to goodness in explanation than the probability of the explanans. And how secure is this alleged inference to the best explanation, as an argument form, or, more likely, maxim? If all the explanations are highly unlikely, am I obliged, nonetheless, to pick and endorse one of them? I hear a great roar from the Notre Dame stadium; either the Irish have scored a touchdown, or an extra point, or a field goal, or a safety, or completed a long pass, or made a long run from scrimmage, or tackled the opposing runner for a loss, or intercepted a pass. Suppose these eight explanations exhaust the field, and suppose the first is slightly more probable than any of the other seven; its probability, on the evidence is .2. Am I obliged to believe that explanation, just because it is more probable than the rest, and even though its probability is much below .5? Whatever happened to agnosticism, withholding belief?..."