One Intelligent Design advocate commented on a previous post, asking me to show him/her how I would argue for Intelligent Design, because, in this person's view, that's the only way to understand something, trying to argue for it, as opposed to trying to disprove it. I wholeheartedly disagree with that view, but I don't think there is any danger in giving a theory (scientific or not) one's best shot, so to speak. So here goes my attempt at arguing for ID, in the most honest way that I am able, with a ending explaining why I am not an adherent (but add to that that ID obviously is not a scientific theory, because science is about invoking natural causes, not supernatural ones).
First, contrary to what many anti-ID debaters have argued, it doesn’t matter what the motivations for the origination and adherence to intelligent design are. Many other scientists have begun fruitful research motivated by a desire to elucidate God’s work, and yet no one disagrees that this doesn’t matter, as long as the results are testable and reproducible. I therefore do not think that ID can be dismissed simply because it is religiously motivated.
Second, in anthropology, criminology, and possibly other areas of science, detecting design is a valid and important undertaking. It is valid to ask the question whether a stone of a particular shape was designed (with the intent of function coming before the form of the object), as opposed to appearance by natural causes (fashioned by geological processes, or in the case of living organisms, evolved). Similarly, despite any preconceptions (and lots of evidence that organisms evolve), we can ask whether there is any evidence for prescient design in living organisms. Did some conscious designer (who need not be specified anymore than a crime lab investigator need suggest who the murderer is, when he concludes that death was not an accident) have a hand (and mind) in the origin of any part of what makes up living organisms?
Without initially considering how to detect intelligent design, I think it beneficial to ponder how such evidence would be dealt with statistically. Imagine that some hitherto unexamined system turns out to show evidence of design. This would be breaking news, of course, and suddenly there would be researchers trying to back up as well as demolish the claim of design. If it is found on second look that there is indeed a way that this system could have evolved by natural causes (a claim that would have to be independently tested for good measure), then the hypothesis that a designer was involved would have to be dropped. The two models (design vs. nature) aren’t equal in the sense that so far many biological systems have been shown to be caused by natural processes, whereas none have been shown to be designed, and the burden of proof is therefore on the hypothesis of design. Evidence that the system evolved therefore rules out the hypothesis of design, and best scientific practice is then to abandon the idea of design in this case. On the other hand, if continued research fails to explain the data by natural causes, then the hypothesis grows in strength, as it becomes more and more unlikely that it will ever be falsified. This is not special to claims of intelligent design. Rather, this is the general rule for all research. As is often stated, nothing in the natural sciences can be proven beyond any doubt, but only, as they say in the courtrooms, beyond any reasonable doubt. This doesn't mean, though, that by disproving evolutionary theory we have proved that a designer designed stuff. However, if evolutionary theory were to fall with all at once (that would take a whole lot of odd results from all over the field of biology, and possibly physics, geology, and astronomy as well), then no other scientific theory would be present to take over, and it would thus lend some credibility to Intelligent Design. However, this setback would emphatically not stop scientists from looking for new scientific explanations for the evidence.
So how about it, then? Do we see design in nature? The short, confounding, answer is yes, we see much design in living organisms. Wings really are designed for flying, the immune system is designed to thwart intruders, and Toxoplasma gondii really is designed to infect mammal eyes, hearts, brains, and livers. Further, the teleological inference is that since they appear designed, then they are designed with those functions in mind. It would appear true that the design is prescient, but that is something that would have to be established. The design that can be inferred so far is not that of preconceived plan, but of exceptional fit to function. Again, in order to make the leap from the latter to the former, it has to be shown more probable that it was consciously designed than designed by nature (evolved).
Then how would someone go about proving teleological design? William Dembski and Michael Behe are the only two people who have proposed any such tests. Dembski proposed specified complexity (basically, it’s too improbable to have evolved so it must be designed), and Behe proposed irreducible complexity (this could not have evolved because taking away any component of the system ruins its function). Specified complexity is widely refuted (as I recall, he even himself admitted something to the effect of it not working, but please look that up yourself), but irreducible complexity far less so (but see this post for a rebuttal). The appeal of irreducible complexity is that it is actually (wait for it…) testable. Data can be gathered, and it can be falsified. This is the signifying strength of scientific hypotheses. You can gather data, and that data can serve as evidence for or against the hypothesis. If I hypothesize that flagella could not have evolved, because taking away any of its components would destroy its function, then that’s directly testable. If trying this out molecularly, and it is found that it never works without all components, and that no other components have homologues elsewhere, and that no components have other functions, and if theory and experiments didn't predict that more than one change can in fact occur at the same time, then we can start taking the hypothesis seriously. That would be a problem for evolutionary theory. But as it turns out, flagella (and all other systems looked at) can be split into smaller components that do serve different purposes, and it is possible (even probable) that two changes could occur at the same time, so that alone shoots big holes in irreducible complexity. The same goes for other systems: blood-clotting cascade, eyes, immune system… Anything looked at so far.
And this is the problem for Intelligent Design at the moment (I’m still trying to argue for it here). Some major setbacks have occurred, but who knows, it might be that some clever(er) person comes around one day to show us that all those things in nature that look so designed by some unnamed very intelligent designer are indeed fashioned with those functions in mind, and not in nature. Until then, Intelligent Design, R.I.P.
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The red swan hypothesis
Intelligent Design is a failed scientific theory
The big Judge John E. Jones III interview
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The Wool Plants
58 minutes ago in Catalogue of Organisms