Thursday, November 03, 2005

On the design inference

One issue that comes up pretty often in the Intelligent Design debate is: When are we justified in assuming that something is the work of a designer? I was talking with Cory Juhl (who's been talking with resident IDer (yeah, we have one (Rob Koons))), about this today. IDers usually come up with some account involving complexity, and say that the complexity of an object is a sign that it had to be designed by an intelligent agent.

I think it's best to just regard design-inference claims as parts of explanations, and evaluate them the way we generally evaluate explanations. Someone who makes a design inference infers that part of the explanation for some object's existence is that it was generated by a designer. So how would I evaluate this explanation?

First, I'd determine how plausible it was that there existed a designer with the capacities and motives sufficient for creating the object. Then, I'd evaluate this explanation on the usual grounds -- explanatory adequacy / simplicity -- against the best non-design explanations.

I don't know how to properly assess the claim that human beings and other organisms are really amazingly complex. (I don't know what a proper metric for the complexity of an object would look like, and it's up to the IDer to come up with a good one.) But when we start considering explanations including a designer who would have all the right motives to make us, just as we are, and all the weird species in the world, just as they are, we're going to need a terribly non-simple explanation to account for all the data. The designer will have to have all sorts of complex motives and mental states. To quote a Joan Osborne parody from some years back:

What if God smoked cannabis?
Do you suppose He had a buzz
when He made the platypus?
When He created earth our home?
Does He like Pearl Jam or the Stones?


Neil Shakespeare said...

You know, this shit isn't even worth talking about, because obviously the "Intelligent Design" folks are just too damn stupid to think. They admit as much. Their whole argument is based on "I'm just too damn dumb to comprehend it". That's all religion is. It's people who have given up on trying to understand. "It's just too complex!" they whine. Meanwhile scientists - who are the ones who TRULY worship existence - search for simplicity. "Simplicty," said Chopin, "is the hardest thing. It is the final thing."

Brandon said...

I'm sad to admit how much of the ID arguments I know, but I can say that there is a sort of stand-in for what Justin calls "designed-ness," in contrast to mere complexity (and its near-cousin, "irreducible complexity"). Neo-Creationist William Dembski (who is as sinister and creepy in person as he is in his picture - I saw him speak at UGA when I was an undergrad) uses an analogy to cryptography and the procedures that mathematicians and scientists use to discern "information" from mere randomness in number patterns and so on.

On the face of it, the simple version I gave leaves them open to the obvious objection that cryptographers and mathematicians face a blob of seemingly-random numbers and letters with the assumption that at least SOME of it is genuine information. The same is not necessarily true in the natural world.

But I don't really know the whole story. Dembski claimed (when I saw him) that there is some equation or mathematical formula that is accepted by some scientific community that can be applied to a mish-mash of data and discern whether it was "generated by an intelligence." Dembski claims that DNA (or something like it) generates the "design" flag when you feed it into the formula.

All of this seems profoundly dubious to me, but I can't speak to the science, per se.

I can also tell you that Dembski kicks you off the comments section of his blog, and deletes your comments, if you disagree with him. So in his "professional" life he tries to use a filter to find genuine information, but in his spare time he uses a filter to keep it out.

Jim said...

President Jimmy Carter, quite a religious man, has been appearing every where lately (to sell his book) and he points out that there is nothing wrong with the belief that there was a Designer, capital D. He points out that we cannot put such ideas in a Science class. A true scientist cannot prove ID in the proper scintific manner, so forget it, Kansas school board members!

Neil Sinhababu said...

Dadahead, the complexity of the explanation will depend on how much work the IDer wants it to do. If the IDer wants it to do only a tiny bit of work, that'll weaken his case against evolution, because he can only say then that evolution leaves a little bit of stuff unexplained. If he thinks that evolution can't explain a bunch of stuff and he wants to invoke the designer to explain all of that, he'll have to posit a very intricate set of desires.

If we don't know how to fill out an explanation, but every way of filling it out would posit a whole bunch of entities, that's a problem as far as simplicity goes.

Justin, I agree about the stars scenario.

I took myself to be giving some very general idea of what designed-ness looks like. When something is designed, you can read the intentions of a creator into it.

Adam, my concern with your view is that if faraway aliens send a probe into our solar system and we discover it, we might be able to explain it in terms of a designer, even if we didn't know of its alien creators.