Thursday, April 10, 2003

God, induction and consistency

More from Kevin Drum, this time on taking the Battleground God quiz. He's surprised by the inconsistency of answering "true" to both of the following questions:

Question 10
If, despite years of trying, no strong evidence or argument has been presented to show that there is a Loch Ness monster, it is rational to believe that such a monster does not exist.

Question 14
As long as there are no compelling arguments or evidence that show that God does not exist, atheism is a matter of faith, not rationality.

The test markers point out that this is inconsistent:

Earlier you agreed that it is rational to believe that the Loch Ness monster does not exist if there is an absence of strong evidence or argument that it does. No strong evidence or argument was required to show that the monster does not exist - absence of evidence or argument was enough. But now you claim that the atheist needs to be able to provide strong arguments or evidence if their belief in the non-existence of God is to be rational rather than a matter of faith.

The problem is basically caused by a tension between ordinary everyday rational standards of evidence, and our desire to be uber-rational.

Basically, in everyday life, we're generally happy to discount the existence of things we don't see evidence for. So for example, we don't think there are little green men (or giant molluscs with tripods) on mars, because there's no evidence for it.

The problem is that this relies on induction. And as philosophers from Hume onwards have been pointing out, induction is irrational - the sun coming up today gives you no rational reason to believe that it will come up tomorrow, and seeing no white ravens doesn't mean that all ravens are black.

The problem for philosophers is that life without induction is pretty intolerable. You can't believe anything at all (which seems to be the case for fundamentalist empiricism in general :). This is probably why, mere pages after saying "induction cannot be relied upon", Hume was relying upon it, and proceeded to do so for the rest of his book.

But back to God: arguments about God tend to descend into a pissing contest of who can be the most rational. Theists will try to trump "I haven't seen God" with "absence of evidence is not evidence of absence"; atheists will try to be more rational than theists and bite that bullet because it's no skin off their nose to do so - they generally have a compelling argument for nonexistence anyway (the Argument From Evil works pretty well), and so why not go uberrational?

So Atheists find themselves forced into some weird beliefs about standards of evidence. If they agree that absence of evidence is not evidence of absence, they have to admit that the UFO cultists aren't irrational when they say the aliens are among us or whatever. But OTOH if they deny it, the theists get to claim the rational high-ground. It's a bit of the bind, and beating theists over the head with the Invisible Taratan Elephant and other consequences of Hume doesn't really get you anywhere. Besides, few people are willing to really dig into induction anyway. Pretty soon you find yourself talking about grue and bleen, and its all downhill from there...

But on the third hand, does it matter? I'd say no, at least not from the atheist perspective. At the worst, they're demanding extremely high standards of evidence for (some of) their own beliefs, which doesn't seem problematic. However, the shoe is on the other foot for theists - they're caught demanding higher standards of others than they do of themselves, which just looks bad.