Monday, October 23, 2006

I Am Correct By Definition. QED.

Good post at Intelligent Design the Future.

It begins:

Imagine wandering into a gymnasium where a basketball game is underway. You glance at the scoreboard: 60-0, in favor of the home team. 'Whoa -- the visiting team must stink,' you say to yourself -- only you then notice, after watching for a couple of minutes, that the visitors are actually outscoring the home team. So what gives? You ask someone who looks knowledgeable.

'Oh, that,' he says. 'The visitors can't possibly win. So we don't bother to count their points.'

Strange way to play basketball, right? Yet something very similar is what Richard Dawkins has long advocated as the most decisive argument in the origins debate. One could call this his Design-Can't-Possibly-Be-True Argument. Variants of the argument have popped up in Dawkins's writings for at least 20 years. Here's a recent version, from his chapter in the anthology Intelligent Thought (p. 103):

Given that chance is ruled out for sufficient levels of improbability, we know of only two processes that can generate specified improbability. They are intelligent design and natural selection, and only the latter is capable of serving as an ultimate explanation. It generates specified improbability from a starting point of great simplicity. Intelligent design can't do that, because the designer must itself be an entity at an extremely high level of specified improbability. Whereas the specification of the Boeing 747 is that it must be able to fly, the specification of "intelligent designer" is that it must be able to design. And intelligent design cannot be the ultimate explanation for anything, for it begs the question of its own origin.

Michael Ruse muttered to me darkly several years ago that Dawkins seems not to understand that this argument makes evolution by natural selection true by necessity -- hardly a happy position for any putatively empirical theory to be in.

Let's go back to the basketball game. If it is possible for the home team to win, it is also possible for them to lose. The outcome cannot be settled a priori, but turns on the actual state of play, namely, on which team scores the most points.

Evolution by natural selection might be the case -- the best explanation, or the winner, via the evidence. As a theory about matters of empirical fact, however, it is also possible that evolution by natural selection might not be the case. It could lose, on the evidence. By logical symmetry, of course, the same situation obtains for intelligent design. Indeed, much of Dawkins's work involves bringing evidence to bear against intelligent design (the backwards retina, transitional fossils, et cetera).

Turns out however that for Dawkins evidence isn't finally decisive. Indeed evidence does not count at all, in the end. Only those explanations that begin with primal physical simplicity, such as natural selection, can possibly serve as real theories. Design loses, no matter what.

When a philosopher hears that a theory about questions of empirical fact cannot be false, or that its competitors cannot be true, his tracking radar turns on. Sure enough, in his review of The God Delusion, NYU philosopher Thomas Nagel locks onto precisely the same worry that caused Ruse to mutter darkly about seductive but unsound a priori arguments.

By framing an argument that appears to win in every empirical circumstance -- design can't possibly be true, whatever the evidence -- Dawkins misunderstands what is at stake in the debate. Evolution by natural selection can't win simply by epistemological necessity...

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