Wednesday, November 27, 2002
The most recent Commentary has an article by David Berlinski (who I think is very interesting) about Darwinism and intelligent design. Unfortunately, it's not on-line. I've blogged about the topic before. I'm returning to it again because I think it's a good intellectual litmus test that most people I know fail. Theocons tend to be soft on intelligent design. They like that it accords with their religious sensibilities, and ignore the fact that it isn't science but is being paraded about as if it is. Libertoids and other rationalists tend to assume that Darwinian macro-evolution is establish scientific fact and that all critics are crypto-fundamentalist religious loons. It is very difficult to have an intelligent discussion about our origins. I find that interesting.
Berlinski's main point against Darwinism is simple: there are strong mathematical arguments against macro-evolution operating in a Darwinian fashion in the amount of time available, and no good mathematical arguments in favor. Those that have been trotted out turn out to be fraudulent; they do not test natural selection but artificial selection. For example, when Richard Dawkins put together a computer program to show how an eye could evolve from a light-sensitive patch of cells, the program knew as part of its design that it was aiming for an eye; it selected not by having organisms with different proto-eyes compete with one another for resources but by killing off the organisms whose proto-eyes were not progressing towards complete eye-dom. That's how dog- and horse-breeding works; it's not how natural selection works.
This, of course, doesn't prove Darwin was wrong. It only illustrates that macro-evolution can't work in exactly the same way as micro-evolution, and that we, in fact, have no good theory of how macro-evolution does work. That's a fair description of the state of evolutionary theory. We have a broad philosophical theory - the theory of natural selection - that we assert is sufficient to explain macro-evolution. And we have a timetable of macro-evolution that makes sense with the fossil record and with our taxonomy of living organisms. But we have very little idea of how it all actually works.
Berlinski's second point, though, I find more problematic. He asserts, basically, that Darwinism is based on a philosophical pre-supposition that is non-scientific. To whit: philosophical naturalism, the assertion that the material universe is a closed circle of causes and effects which explain everything within it. I agree with Berlinski that this is a pre-supposition of Darwinism. I disagree with him that this is non-scientific. On the contrary, I think it is a necessary axiom of science.
To illustrate why this is the case, consider the opposite situation: a science that accepted extra- or super-natural intrusions on the natural order. How could these be "studied" scientifically? Science, after all, is a pragmatic endeavor aimed at predicting future events. Future events can be either strictly deduced from known causes, or can be understood statistically for those phenomena that exhibit an irreducible element of chance. If G-d - or an evil demon - periodically intervenes in the natural world in violation of its natural laws, how could "science" possibly predict these interventions and their consequences? Berlinski rebukes the intelligent design theorists periodically for their refusal to explain how the character of the designer is revealed in the design - why, for example, a peacock's tail of such splendor, and not a donkey's tail? - but this is another way of talking about the psychology of G-d, and psychology is a branch of science. We're talking, ultimately, about reducing G-d to a series of laws similar to those that govern human psychology. Doesn't that bring G-d, in some sense, down into the natural world? In what sense is He outside the natural order if we can devise a predictive psychological understanding of him?
It is not the task of science to provide a comprehensive understanding of reality. Many aspects of reality remain beyond science's grasp, and it is reasonable to speculate - though probably impossible to prove - that they will always remain beyond science's grasp. Berlinski talks about Hoyle's famous disconcert at discovering the nuclear resonance between helium and beryllium, a resonance essential to the creation of carbon, and hence to the development of life. With a slight change in these values, the universe would be lifeless. Does that prove there is a G-d, designing the universe? Or does it prove the anthropic principle that things in our universe are ideally suited to life because we, in retrospect, are here to observe our universe, and thereby called it into being? Or does it prove that there have been a multitude of "universes" existing in different dimensions, with an infinite variety of nuclear resonances, and we, as living beings, of course live in the universe that has the proper resonance for the development of life? Is there any pragmatic difference between these views? Not to a scientist, because none have any utility in predicting the future, and that is what science is for. Properly, then, these speculations lie outside of science, and their pragmatic difference exists in how humans who believe one or another explanation behave.
My own supposition is that there are a number of irreducibles in the universe. I do not believe that consciousness can be reduced. I don't even know how to talk about the question, and all the hard-AI types who are convinced that consciousness "emerges" out of complex systems, or that consciousness is an "illusion" - the Dennett and Pinker types - are just waving their hands and engaging in mystification through language. An illusion is when you see something that isn't there. If my consciousness is an illusion, who is the "I" who is witness to that illusion? I can't see any way of theorizing about the irreducible element of consciousness - the subjective experience of being, of selfhood - that is in any way scientific. So I suspect it is irreducible. I suspect similarly that the deep structure of the universe is irreducible. Asking "why" nuclear resonances are what they are will turn out to have no answer; better: it will turn out to be a poorly formed question. We'll have discussions about symmetry-breaking in the nanoseconds after the Big Bang, and maybe we'll discover that symmetry "had" to break in a particular way. But all that does is push the question down another level: why did symmetry "have" to break that way? Couldn't the laws that determined our physical laws have been different?
There's no bottom to this kind of argument. Science can only investigate how things are. It cannot - by its nature - investigate why things are. Unmoved movers and intelligent designers are outside the realm of science; they live on the parts of the map that read, "here be dragons." That is why science must posit philosophical naturalism - not because such naturalism is true, but because without that axiom you can't do science, and where that axiom does not appear to obtain science has reached an impasse.
The whole debate about evolution and intelligent design usually comes up in reference to education: how do we teach children science without offending religious belief? I do not think this is nearly so difficult as it is usually made out. We do not want to teach scientism; we want to teach science. Therefore, we should frankly tell children that science is not religion. Religion is concerned with the nature of things, in the deepest sense. It tells us why things are as they are, and what we should do with ourselves given that fact. Science is concerned with how things are, not why. Science is about measuring gravity, not answering why it should exist. So with evolution. Since science can only investigate a closed material circle, the proper question for science is: can one come up with an explanation for how the variety of organisms we see came to be? There have been many theories. Perhaps they all came into being together? No; the fossil record is evidence against that. Perhaps the universe has always existed, much as it is now? No, and ditto for the reason. Perhaps one organism evolved into another over time? Perhaps. If so, how? Vitalists would argue that there is a natural force - an elan - "pulling" evolution "upward" towards greater complexity. That's what was usually meant by evolution before Darwin, and it was for this reason that evolution, originally, was embraced by many Christian clergy: the force was identified as the hand of G-d operating in the universe. Unfortunately for advocates of such a theory, there is no evidence of such a force. Perhaps organisms adapt to reality in their lifetime, and their offspring inherit these adaptations? That's what Lamarck thought, but again, it turns out to be unsubstantiated by evidence. Finally, Darwin posits that random variation and natural selection are sufficient to explain the evolution of life. Is he right? Perhaps. We do observe micro-evolution operating through precisely such processes; perhaps macro-evolution operates the same way. And we do observe what looks like macro-evolution in the fossil record: the transformation of dinosaurs into birds, for instance, or the development of the mammalian ear. But we also see things that fit uneasily with the hypothesis of Darwinian macro-evolution - such as the pre-Cambrian explosion - and there are mathematical arguments against the possibility of macro-evolution in the time available. So where does that leave us? Darwin has some evidence, no other theory that passes for scientific has any evidence, hence Darwinism is the working hypothesis of evolutionary biologists and other scientists today. We don't know that it's true. It's not a theory with the strong support of General Relativity or quantum mechanics. But it is still the best theory going, and whatever scientific theory emerges to supplant it will have to do a better job of explaining the origins and development of life, operating from the same assumption of philosophical naturalism, that chance and the laws of the universe are sufficient to explain how the universe works.
Is that account going to offend religious sensibilities? It will certainly offend biblical literalists, but then, any scientific doctrine must offend them. It should not offend any religious believer who also accepts the nature of scientific inquiry. G-d still has plenty of living space out there with the dragons. The spaces where He lives may be the most important ones to us as humans. And mapping out the edges of its domain is properly a scientific project. But there is no place in the science classroom for "theories" about dragons.