Motus Mentis

Yesterday I left a comment on a post by Bill Vallicella (who maintains one of the most interesting sites anywhere in the blogosphere) about Richard Dawkins’ antipathy toward the “theory’ of Intelligent Design. Dr. Vallicella has responded here, and I’ll take this opportunity to respond to his response.

Some particulars:

I suggested that Dawkins’ position is not that ID’s reasoning is circular, but rather that it merely adds an “unhelpful regression’ without really explaining anything (I’ve already pointed this out in my own rather snarky post about ID). Dr. Vallicella says:

Part of the problem is that it is not clear what Dawkins is claiming. He could be read as accusing the IDist of proferring a circular explanation. Indeed, this is the way Alvin Plantinga, in Darwin, Mind, and Meaning interprets a similar passage in another of Dawkin’s works. So I’ve got Big Al on my side.

There is also the possibility that you prefer, namely, that the IDist is explaining a complex phenomenon in terms of something that is also complex, and so also in need of having its complexity explained. I take it this is what you mean by an “unhelpful regression.’

But as I pointed out in my post, an explanation of B in terms of A can be good even if A remains unexplained. Suppose Smith’s elevated blood pressure is explained by her anxiety at being in the doctor’s office. (White Coat syndrome) The explanation may or may not be correct. But if it is, it is correct whether or not one goes on, or even can go on, to explain why the patient is in the office.

Now suppose that the bacterial flagellum cannot be explained ”˜from the bottom up’ from simpler elements; suppose the appearance of design cannot be explained without invoking an intelligent designer. Then what is the problem with the explanation?

The whole issue is whether or not the bacterial flagellum (e.g.) is irreducibly complex. If it is not then there is no call for an ID explanation. If it is, then there is. Therefore, pace Dawkins, there is no mistake in reasoning being committed by the IDist; there is instead a difference of opinion about the truth or falsity of an empirical proposition.

I have no quarrel with most of what is said here. I certainly agree that “an explanation of B in terms of A can be good even if A remains unexplained’, although of course that simply means we still have work to do. As far as I can tell, though, ID proponents generally make no real exertions to pursue the question of who, exactly, this “Designer’ might be. Presumably it is God, although lip service is paid to aliens from time to time. If any “scientific research’ is being done on this important question by the ID camp, I’ve yet to hear of it.

That being said, pointing out a shortcoming in the practice of ID “science’ does not constitute a refutation of the philosophical position. In fact there is little or nothing that can be brought to bear to refute ID, for the simple reason that the examples given in its support are always precisely those biological phenomena whose origins are not well known. This is very different from putting forward an example in which the history of the organ in question is in fact very well mapped, but which still has no satisfactory explanation in terms of Darwinian principles. In cases where the history of such development is clearly shown, evolutionary mechanisms can always be found. Regarding the notorious flagellum, I quote John Rennie, responding to ID proponent Michael J. Behe of Lehigh University:

Evolutionary biologists have answers to these objections. First, there exist flagellae with forms simpler than the one that Behe cites, so it is not necessary for all those components to be present for a flagellum to work. The sophisticated components of this flagellum all have precedents elsewhere in nature, as described by Kenneth R. Miller of Brown University and others. In fact, the entire flagellum assembly is extremely similar to an organelle that Yersinia pestis, the bubonic plague bacterium, uses to inject toxins into cells.

The key is that the flagellum’s component structures, which Behe suggests have no value apart from their role in propulsion, can serve multiple functions that would have helped favor their evolution. The final evolution of the flagellum might then have involved only the novel recombination of sophisticated parts that initially evolved for other purposes.

The ID position depends entirely on there being “irreducible’ complexity. But whether any particular instance of complexity is in fact irreducible is an open empirical question. We are left once again with a “God of the Gaps’, and the problem with defending such positions is that the gaps are always shrinking. The evolutionary viewpoint, in which Design is accomplished by “cranes’ standing on simpler ground and lifting from below, rather than by the extra-natural “skyhooks’ favored by creationists and their ID fellow-travelers, keeps winning new territory, leaving the IDists scurrying always for some new example at (or beyond) the fringes of our ken. I do agree, though, that a genuine example of truly irreducible complexity, an incontrovertible instance of sophisticated design entering biological space without any antecedent pathways of evolution by selection, would deal evolutionary theory a heavy blow. This is why Darwinian theory is actual science: it meets Popper’s criterion of falsifiability. I don’t see how one can possibly falsify the vague assertions of Intelligent Design other than by gradually filling the gaps, a task that is proceeding apace. Dr. Vallicella says:

”¦there needn’t be any fallacious reasoning in invoking an intelligent designer. The question is whether there are any gaps that cannot be filled naturalistically. If there are, then there cannot be anything wrong with invoking an intelligent designer.

Again, I agree with this. We have no reason to believe that such gaps exist, though. Certainly there is no evidence that they do.

Finally, this from Dr. Vallicella:

I will not try to convince you that naturalism is false or that God exists ”” that would be too ambitious, and I’m a sober, realistic, conservative type of guy ”” but I will try to convince you that there is a genuine issue as between naturalism and theism. In particular, I will try to convince you that Dawkins is quite mistaken that in this case one side is demonstrably right and the other demonstrably wrong. Or, to put it another way, that science by itself can establish that theism is false.

No argument here. The conviction that God (or any sort of user-defined transcendant Deity) does NOT exist is no less an act of faith than the belief that such an entity DOES exist. Thinkers on both sides of this issue have tried to press Science into service to buttress their arguments for centuries, to no avail. The question of the existence or nonexistence of God is simply not a scientific issue at this time (though perhaps ideas or methods now unimaginable may someday be brought to bear). My own view is one of curious agnosticism. I will say, though, that until such time as ID puts forward some testable (and therefore falsifiable) predictions, it has no place in a science classroom.