Most effective in our debate was Ken Miller's attack on Behe's notion of "irreducible complexity." According to Behe, some biological entities are so complex that they simply could not have come about through the slow natural process of natural selection. Or by any natural process for that matter. They must therefore have come through "intelligent design." By way of example, Behe instanced the mousetrap: a contraption for killing small rodents, and something made of five separate parts (the base, the spring, etc.). Take any one of these parts away and the trap fails to function, argued Behe. It must therefore have been planned and put together at one point in time, and started life right out as fully functioning for its intended purpose. (It was not for instance a door stopper adapted for another end.)
Miller turned up for our debate with a mousetrap, or rather with two mousetraps. One in its original five-part form and one with a piece missing but the other parts bent so that it still functioned. With great effect, at a crucial point in the debate -- just after Behe had given an exposition of his thinking -- Miller whipped out his mousetraps, original and modified version, and showed just how lethal for Mickey and Minnie his modified trap could be. Of course, the New Creationists fought back, but really we all knew that that was the end of that line of argument. And more. Since the mousetrap example had been shown so obviously fallacious, strong doubts were now seeded about the worth of the other parts of the Creationist case. Miller was terrific, and we all knew it.
- Michael Ruse