Friday, November 12, 2004

"Theories" are not "Conjectures"

I respect Michael Lopez enormously and I love his blog. He always gives me food for thought, and often in the best of ways: he says something that I think that I might disagree with, but I'm often not sure why or how, which gives me cause to explore my own thinking and such. That's always golden, whether I end up agreeing or disagreeing with him.

But he goes way off the rails in this post about an Evolution vs. Creationism case. The particulars are that some school district wants to slap a PMRC-style warning label on science textbooks to the effect that "This book contains material about evolution!" (Which has me wondering when National Geographic will have to start carrying similar labels about aboriginal breasts.)

Michael commits the all-too-common "It's only a theory" error when he says this:

Evolution, for all its marvelous explanatory power, has not been proven. Now, it hasn't been disproved either, but there are enough holes in it to keep its famous moniker "The Theory of Evolution" and not to promote it to the rarefied company of, say, the Laws of Thermodynamics.

This is all very, very wrong, in a number of ways.

First of all, the Laws of Thermodynamics are not things that got "promoted" to "Physical Law-hood" from "Theories"; the Laws of Thermodynamics are theories. A theory, in science, is as close to fact as you get, but to most people, the word "theory" carries with it a connotation that a "theory" is little more than a hypothesis that's got some evidence going for it. If we're going to play the "Evolution's a theory" card as an implication that there are other, perfectly good theories to explain the same stuff, then we have to take similar approaches to other theories: plate tectonics, for one. Or Special Relativity. Or General Relativity. Or universal gravitation. Or Thermodynamics. The Laws of Thermodynamics are the theoretical laws that govern the theory of thermodynamics. They are not theories that have been "proven".

And this is because theories are never "proven". Proof is not something that happens in science; what happens is confirmation: the gathering of evidence that either strengthens a theory or either weakens or outright disproves it. Now, Michael cites earlier examples of theories that fell by the wayside, and he's right: we now know that phlogiston theory is wrong, as is the theory of the luminiferous aether. But this doesn't imply that evolution is some nice story that has a ton of holes in it, nor does it imply that evolution is just waiting for some intrepid anthropologist or paleontologist or biologist to uncover the smoking gun that reveals it's all bunk.

Michael also trots out the "critical thinking" bugaboo, accusing scientists of being dogmatic about their insistence upon evolution. I've always found this baffling, because no one (outside a few cranks like the Flat Earthers) insists that geologists are somehow going against the grain of science in their current acceptance of plate tectonics. Neither does anyone complain about the fact that you won't find an astronomer who refuses to toe the Copernican line. Somehow, in all those cases, we're all willing to admit that the scientists believe these things because they're true; but when it comes to evolution, it's suddenly a case of "Whoa, there, scientists! You guys aren't supposed to be so dogmatic!"

What it all boils down to is that opposition to evolution, or the endorsement of either Creationism or its more handsome younger brother Intelligent Design, isn't born out of "critical thinking" at all. What it's born from is the desire on the part of an awful lot of people to have evolution not be the way things are. Why so many people are emotionally invested in evolution's failure is beyond me, but don't tell me that they can act this way toward one theory (and I use that word here in its full-blown scientific sense) and no other theory and tell me it's all about "critical thinking". Because, hell, while we're at it we might as well slap a similar sticker on high school physics texts that they contain material about universal gravitation, and then insist that we're merely encouraging "critical thinking" from students who would never know where to start to look for evidence against universal gravitation even if they wanted to.

This "sticker on the textbook" stuff isn't about intellectual honesty, or the "true spirit of science", or any such thing. It's about encouraging students to believe that one scientific theory that is nearly universally accepted by scientists is false after all, and that's it. It's an encouragement of Creationism, and nothing more.

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