Archive for August, 2007

Ramblings on certainty

I am certain that there is no god.

For sufficiently small values of “certain”.

Okay, let me explain. There’s a topic that comes up occasionally in various places that goes along these lines: An atheist is someone who is convinced that god doesn’t exist. However, you can never be absolutely sure that there’s no god; there’s always a chance that you haven’t looked hard enough, or in the right place. (Some variations say that in order to know that there’s no god, you’d have to be omniscient, so you would be the thing you claim doesn’t exist.) Therefore, all atheists are actually just agnostic, and whether you believe in god is just a matter of faith. (The argument usually goes on to talk about Pascal’s Wager.)

Logically, there’s nothing wrong with this argument. However, it leaves me wondering what kind of universe the person making the argument thinks we live in. “Certainty”, defined as being 100% sure beyond any conceivable doubt, is a rare thing indeed. I’d go so far as to say that it doesn’t exist. We quite regularly claim to be certain about things that could actually be false for any number of reasons.

For example, I’m certain that I don’t own a Lamborghini. I have no problems saying, point blank, “I don’t own a Lamborghini.” But how sure am I, really? Maybe a rich relative died yesterday and left me a Lamborghini in their will. Maybe someone broke into my garage and did a conversion job on my Corolla in the half hour since I got home. Maybe I had a stroke in exactly the area of my brain that remembers what car I drive. You’d quite rightly say that these possibilities are far-fetched, maybe absurd; but it’s not, strictly speaking, impossible.

At the very least, everything I claim to know is subject to the brain-in-a-jar exception; anything I think I’ve experienced could have been fed directly to my senses as part of a simulation, a la The Matrix. My understanding of logic might not even be valid, in which case anything could be true.

So it’s impossible to be absolutely sure of anything. However, there’s this slight issue that we actually have to live in the real world, where we need to act on things we know on a regular basis. If people who made the “if you can’t prove it 100% then you don’t really know” argument about atheism applied the same argument to, say, gravity, they’d have trouble getting out of bed in the morning for fear of falling to the ceiling. They’d never be able to answer anyone who asks, say, what their name is, because they couldn’t be sure that they’d remembered it right. I’ll stop now, but the point is that we regularly act on things that we’re almost completely sure about. That’s why the standard of proof in criminal law is “beyond reasonable doubt” – there’s always some doubt, however remote.

Now for the semantic part of the argument… The word “certain” has a tiny amount of fuzziness in practical usage. It has to, otherwise you could never rationally claim to be certain about anything. Anyone who claims otherwise is holding the word to a standard that makes it impossible under any circumstances. Of course, you can define a word however you want, but a word that describes something that can’t exist isn’t particularly useful.

So, I’m certain that there’s no god. I might be wrong. But I don’t think so.

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