unintelligent design, intelligent design, appeal to ignorance, affirming the consequent, and the scientific method th

R Dawkin's strongest arguments against intelligent design point out how badly engineered bodies seem to be. Examples include the following:

1. the vagus nerve, which starts from the brain and wanders needlessly through the body (around the heart) before comiing back up and linking to the trachea (the length of this nerve is most notably excessive in the giraffe, points out RD);

2. the vas deferens, which starts at the gonads and then circles needless around the bladder on the way from gonads to penis [I wonder if the inefficiency here has to do with the parallel role played by correlate in females];

3. the human back [I wonder if those stone age guys in New Guinea have backaches: perhaps it's our chairs that are unintelligently designed]; and

4. the eye, which places the nerves inside the area where light must pass, creating an obstacle course for signals [I need to recheck each of these examples to see if I've accurately represented them] and creating a blind spot in the middle of the retina (?) (a.k.a. watchahmacllit);

and

5. he gives plenty more examples that I just can't remember at the moment.

At least the first two are good arguments against creationism, which would give no role to evolution in bringing about life forms in their present form. That is, if God miraculously and immediately determined the precise structure of each animal species, then RD has given very good initial evidence that this would have been bad engineering, for there is no reason to make these nerves/channels needlessly long. RD also shows how it makes perfect sense for there to be such flaws, given the evolutionary history of the structures in question. For example, the vagus nerve evolved from a more primitive linkage ... (uh, I forget what he said here, but it has something to do with fishes and modularity). In any case, he gives a quite plausible explanation of why it is that the vagus nerve, true to its name (vagus = Latin for wanderer), presently wanders about before arriving at its destination.

If RD's target is creationists who use intelligent design arguments as a justification for the rejection of evolution, then he is surely on target. But the same cannot be said if his remarks are directed against the ID theory of the likes of Michael Behe. For the latter accepts the evolutionary narrative without reservation yet still believes in some sort of intelligent design, so I'll call his theory IDE, or intelligently designed evolution, and I'll use IDC to refer to the theory of those who would think intelligent design disproves evolution . Earlier in The Greatest Show, Dawkins points out that the combined mutation of two bacterial genes undermines the creationist appeal to irreducible complexity. But the very person who coined the term "irreducible complexity" rejects creationism. Behe doesn't believe natural selection and random mutation suffice to bring about changes of the species, but he does think that sort of change occurred. So credit for introducing the phrase "irreducible complexity" goes to a proponent of evolution rather than a creationist. So Dawkins criticism of ID, inasmuch as it relies on randomness arguments that point out the same in nature are thoroughly off target. Such is the argument used by Dawkins himself earlier in the text against "irreducible complexity."

EDIT

, but when he does, however, he attributes it to creationists. I suppose he is thinking of that 40%, of Americans who are creationists and who would find it natural to use ID as a kind of fig leaf to cover over their anti-scientific rejection of evolution, but he is not addressing the Behe point for point.

That is not to say that he leaves Behe's argument unscathed earlier in this work, for if he refutes the notion of irreducible complexity as such, then it is incidental whether or not it is coupled with an acceptance of the evolutionary narrative (by evolutionary narrative, I mean the story of how present life forms descended from earlier ones, but without including commitment to any particular explanation of how that occurred: one might, on the basis of fossil record, accept evolution as a fact without yet understanding how natural selection and mutation made it possible).

RD's earlier argument may or may not be cogent against Behe: I posted something on that earlier (discussing bacteria and citrates). But what about the examples he gives in this chapter?

The chapter in question (i.e., the later one) does not touch the ID arguments of that posit God (or a demigod) as intelligently designing evolution itself. And the designer of evolution would not only be an engineer but also an economist. If the goal is to get from the earlier life form to the later one, then the cost of getting there is relevant enough to let some things messy. The human back is pretty darn good, considering it was derived from a four-legged animal. And of course, after watching an olympic gymnast perform, it seems that it works quite well on a good day anyways.

The first objection to intelligent designer of evolution that comes to my mind is that it is, to quote a professor who wrote to me a couple of years ago, operationally vacuous. Sure, you can say that God or a demigod designed evolution so that it would happen just as science says it did. But don't call that science, because there is no way to disprove it. And if we subtract this additional layer of causality, everything seems to go on just fine anyways, so why bother? (Echoes of the invisible spaghetti monster argument). I do think Behe has a reply to this, but am not convinced that it is successful in showing how close to zero the probability is that life forms would become complex as they have become.

Ah, what a series of digressions! I'm trying to write everything going on in my head before wife and kids wake up... so let me get to the appeal to ignorance, which was supposed to be the point of this post.

Dawkins argues, see this example of wastefulness in the structure of the body? It shows the lack of design. A kind of modem tollens argument: if the body were designed, then it would be efficient, but it is not, so it is not designed. An counter argument, of course, would be to point out benefits of the system as it is. For example, with the eye, one IDer has argued that having the bloodvessels in front instead of behind the ________ is a better way to get lots of blood to where it has to go. That may or may not be a sound argument, but it is at least a valid one.

If we set aside hermeneutical charity for the moment, we can recast Dawkins' argument as an appeal to ignorance. Rendered in this manner, he would argue that because we cannot demonstrate any purpose in this or that structure, there isn't any. Such a rendering, however, would overlook the point that it simply looks less efficient than it could have been. RD relies on an analogy with common sense notions about what looks designed/undesigned. But so do ID proponents when they argue that organic structures look designed. Yes, they can be characterized as making an appeal to ignorance. But that is only if they ignore or dismiss the arguments that natural selection/mutation suffice to explain the evolutionary narrative. If they offer arguments, however unsound those arguments might be, against the sufficiency of NS/M, then their analogy with engineering is not automatically disqualified any more than Darwin's analogies with breeding (artificial selection) and economics (competition for limited resources).

In fact, every theory (even theories that are so confirmed that one must be either loco en la cabesa or the next Einstein to contradict them) can be characterized (often unfairly) as assuming that the favored hypothesis is true because alternative explanations have not been demonstrated.

Take the following: If E1 then P:

where E1 is the explanation #1 (the favored one); and P as the phenomena being explained.

In order to assert that E1 is the best explanation, you must show that other Es don't explain as well. That is what ID tries to do; that is what every theory tries to do. If ID tries to do this, however, by showing that there are gaps, then the appeal to ignorance criticism is well deserved. For every scientific theory has gaps. Gap arguments are inherently appeals to ignorance.

I have to leave this off, but the question I wanna kick around is whether any criticism of a theory consists of pointing out gaps: I dont' think so. I think the good criticisms consist of pointing out unsuccessful predictions/retrodictions. If ID does that, then if its is off base, the criticism should be empirical. If ID simply points out gaps,then the criticism of it should be on the basis of principle, i.e., bad method.

The only way to attack ID is to argue for the sufficiency of NS/M, not to object as a matter of principle to supernaturalist (God did it)/preternaturalist (a being less than God but greater than us did it) explanations. The latter approach belies circular reasoning.

there in the following way:

if we see efficiency in all phenotypes, then there is an engineer; we do not; therefore there is not. Cast in this way, RD's argument not only denies the antecedent, it is an appeal to ignorance.