Thursday, August 25, 2005

God's Design

Yet another article in the NYT about the evolution / intelligent design debate. There's not much new in the article--the story continues with the same old characters saying the same old lines. What's different--though not new--is the story's attempt to give a little more detail from the arguments of the two sides, trying to explain random mutations, on the one hand, and the concept of irreducible complexity on the other.

I've discussed this debate in several installments of An Examined Life, and I've nothing new to add to the kerfuffle either. One thing that puzzles me about the whole thing is the attitude, usually discernable on both sides of the debate, that the two ways of looking at the origin of life are orthogonal. This attitude has existed since Darwin first proposed his theory: some folks assume that, if life arose as a consequence of random forces interacting with adaptable genetic structures, that fact alone is sufficient to show either that there is no God or that, if there is a God, God is not responsible for the origins of life on earth. Other folks assume that, if the major monotheistic religions are to be preserved, then it is a necessary condition that one reject scientific hypotheses about the origins of life that involve random mutations interacting with naturalistic forces (such as natural selection).

One side makes a mistake about a sufficient condition, the other a mistake about a necessary condition, in my view. (I pass over in silence the literalist argument that holds that the text of Genesis must be interpreted as history that is literally true in a non-metaphorical way, since that view is not supported by any evidence, either theological or scientific; it has been explicitly rejected by theologians as early as St. Agustine and has been rejected by the Pontifical Biblical Commission.) Part of the problem lies in the fact that many non-scientists find mechanistic (top-down) explanations in science easier to understand, and any theory involving genuine randomness is already on the road to misunderstanding. But more important than this is the fact that virtually nobody, either scientists or non-scientists, adopt a teleological view of the world these days. Evolution by natural selection, for example, is desribed as "directionless" in the sense that adaptations are merely interactions between a genotype and its environment: the genome is not "looking for" some final phenotype to express, if it can, but is rather responding to whatever selection pressures are applied to it within its environment. For the evolutionary biologist, talk of teleology is dangerous precisely because it appears to introduce the notion of purposefulness into a process that is, for them, essentially purposeless. This view is found both among scientists, for whom all of physical reality is governed either by deterministic scientific laws or irreducibly stochastic forces at the quantum level, and among ID theorists, who assume that if a scientific theory says that this is the mechanism by which something occured then that precludes the possibility of some other ultimate cause (we have also lost the distinction between proximate and ultimate causation).

But there is an equivocation here on the term purpose. The biologist does not want to think of the genome as having a "purpose" in the sense that it is slowly evolving things towards some end-state, whether a perfected one or some other kind, and the ID theorist does not want to think that the world is just a random place in which "life happens", since complexity, it is argued, must be interpreted as signs of designedness. But both of these views miss the mark because they make unwarranted assumptions about what it means to say that the universe is teleological.

To see how this is so, consider the recent development in the debate whereby those on the ID side have begun to distance themselves from what used to be called "creationism". Intelligent Design, it is argued, is not a specifically religious interpretation of the cosmos, it is, rather, nothing more than the argument that the universe exhibits evidence of having been designed by an intelligent designer. If this is so, however, ID is fully consistent with evolutionary theory--there is literally no conflict whatsoever, since an intelligent designer could very well have "designed" the cosmos in such a way that life originates and evolves through a process of natural selection. It is only if one interprets one theory or the other as contradicting the other that there is a real conflict. If the evolutionist wants to suggest that random drift, or fully natural processes like selection pressure and adaptation, exclude the possibility that these processes were put into place by an intelligent designer, he is simply mistaken. If the ID theorist wants to argue that evidence for design excludes the possibility that differential reproductive success can lead to changes in the genome and, ultimately, speciation events, he, too, is simply mistaken.

In short, there is no important difference at all between ID and evolution other than an a priori assumption about who's running the show. No a priori assumption will ever be settled by empirical science alone, but neither can it be proved from other a priori principles without violating the Principle of Sufficient Reason.

Back when the debate was between "creationists" and evolution theorists (well, let's call it like it is: between biblical literalists and biologists) things were a lot simpler, at least for me: creationism can be rejected because it represents a heretical approach to biblical interpretation. Things aren't a lot different now: there are still ID theorists who subscribe to the theory primarily because they are, deep down, biblical literalists. But of course the reasons why someone subscribes to a theory have nothing to do with whether the theroy is actually true or not. Some evolution theorists, after all, may very well subscribe to it precisely because they think it proves religion wrong, and they are just as mistaken as the biblical literalists. But those who subscribe to ID because they are teleologists are not, in fact, at odds with evolutionary theory at all, even if they think they are.

1 comment:

Steven said...

Dear Sir,

I should have posted this response here rather than at Speculative Catholic, my apologies to both of you.

This restates an argument I've been making since before this became a topic among blogdom. Both neodarwinism and ID are science (change occurs through time by the slow changes which occur in a species) and philosophy (on neodarwinism's side logical positivism in its mutation as empiricism [i.e., all of this change is the result of random happenings] and on ID's side theism or design [something had to guide this].) Both philosophical statements lie outside the realm of science. (Rather like almost all of Stephen Jay Gould's science depended sensitively on the marxist underpinnings of his thought--hence we have his theory of contingency, which, barring the invention of time machines, is an absolutely impossible exercise in speculation dressed up as science.)