"Your problem is just that you can't imagine how it could happen"

Michael Behe gets it all the time: the charge that "Your problem is you just can't imagine where your so-called irreducible complexity came from." He says there are some biological features that could not, in principle, have arisen by blind, unguided Darwinian processes. Critics say, "Just because you can't imagine how it was done, that doesn't mean it couldn't have happened. You're only suffering from a failure of imagination."

I feel like I'm in good company, because I got the same charged aimed at me the other day. It's a red herring, though. Imagination isn't the issue. What Behe is saying with his irreducible complexity argument, and what I was writing about when I was charged with the same, is not, "This would be very difficult." Rather, it is, "This is impossible in principle." Let me illustrate the difference, and why those who disagree cannot wave it away so simply. (My story is partly in honor of yesterday's events.)

Peter is a visitor from somewhere in Europe. He calls his friend Mark one evening and says, "I just saw my first football game here. The final score was 4 to 1."

Mark answers, "Well, it looks like we have a confusion in language here. They call it football in British English; over here we call it soccer. Surely you've seen soccer games before, back at home where you grew up."

Peter says, "Yes, but this wasn't soccer. This is what you call football over here. You know, the game with a pointy ball, and touchdowns, and all that. I didn't understand everything I saw, but I liked the game anyway."

"You said the final score was 4 to 1?"

"Yes, that's right."

"Uh, Peter... are you really sure you were watching football?"

"Look, Mark, I was there. The ticket said 'football' on it. The ball looked like one of your footballs. They had first downs, they had goalposts on both ends of the field, they started it with a kickoff, and they had a huddle before every play. (I never heard of a sport with so many committee meetings!) I'm telling you, it was football."

"But Peter, that's impossible. You said the final score was 4 to 1. You gotta know, for a team to end up with 4 points in football is, like, really, really unusual. I don't know if it's ever happened."

"Sure, sure, I know. The guy sitting next to me said he had never seen it before. The team had two safeties. Even I could tell it was way out of the ordinary. The odds against it must be extraordinary."

"But Peter, that's not all. Getting 4 points in a game is really, really unlikely. But ending up with one point isn't just unlikely. It's impossible."

"Impossible?"

"Yes, impossible. You see, in football, teams get 2 points for safeties--you saw that. They can get 3 points for a field goal. For a touchdown they get 6 points. Sure, there's a way to score just 1 point, but it's what they call a 'conversion,' and it only happens after a touchdown. No touchdown, no conversion. No 6 points, no 1 point. There's no way to end up with just 1 point in football."

"Mark, Mark, Mark. You know what your problem is? You're suffering from a serious failure of imagination. Of course you can get just 1 point! Just because you can't think of a way to do it doesn't mean there isn't one!"

This little story illustrates the difference between a difficulty (an unlikelihood) and an impossibility. For a football team to end up with four points that way--two safeties and no other points scored--is way out of the ordinary, and I wonder if it has ever happened in college or pro football. Still, if you know the game, you can imagine it happening. But as Mark said, for a team to end up with just one point is logically impossible. This is what Behe says is going on with Irreducible Complexity.

Now, if someone wants to show that the logical impossibility I've just illustrated isn't impossible after all, they may also be able to do it. For some readers it won't be difficult at all, for there actually is a solution to this problem that would be familiar to some readers. They won't solve it, though, by telling me to use more imagination. They'll solve it by applying different information or thinking to the problem, in ways for which imagination is utterly irrelevant. (I could be more specific but that would spoil it. Feel free to post the answer if you know it, though.)

In the same way, to show Behe wrong, the disputant needs to bring new information or new ways of thinking to the problem. But saying he's short on imagination is completely irrelevant.

Now, there's one more point to add to this. If Behe's problem really were a lack of imagination, then his Darwinian opponents ought to be able to supply the lack. For over ten years he has been calling on them to propose or to suggest a way that the bacterial flagellum could have arisen by unguided Darwinian processes. He hasn't been asking them to prove or demonstrate their ideas--just to propose them. Just to imagine them. Kenneth Miller said that the Type Three Secretory System answered the problem--that bacteria co-opted that already existing structure. Unfortunately it has since been learned that the TTSS probably came later than the bacterial flagellum. And since 1996 further problems with explaining the flagellum have been uncovered: not just its structure, but also its assembly instructions are also irreducibly complex.

I wish we could call a moratorium on this charge, "You just don't have the imagination." If someone claims that a process or phenomenon is impossible in principle, and puts forth arguments to that effect, then it is those arguments that need answering.

Posted: Sun - September 2, 2007 at 08:00 AM |

Thinking Christian by Tom Gilson getCategoryName("<$CategoryUUID$>");

"Your problem is just that you can't imagine how it could happen"

Thinking Christian by Tom Gilson