Friday, February 04, 2005

A game theoretic approach to choosing a religion

Matthew Yglesias, my second favorite blogger, had a post yesterday in which he argued that in a Christian world-view, the only rational choice is to behave morally because the benefit in the afterlife is infinite while, presumably, the benefit of immoral behavior in the current life is finite. He said:

"...morally good behavior is strictly rational because God's judgment will reward goodness with an infinitely large benefit after death. Bad behavior must always result from akrasia, "disordered virtues," short-sightedness, or some such other thing."

I've never thought of religion in this way, but after some reflection it does seem like this could be a model for Christians' rational decisionmaking. After even further reflection, though, I'm not sure that it actually is. The problem, I think, is that the flip-side of infinite benefit (Heaven) in the afterlife is infinite pain (Hell) in the afterlife. If you act morally you're fine, but one slip-up and you're metaphysically fucked.

In this rational actor model, because the post-death benefit of moral action on Earth is actually infinite, there could be no possible way that rational actors would ever do anything but that which was moral. The problem lies in morally ambiguous situations which, though our President might argue otherwise, are not uncommon in the real world. In those situations, rational actors would be unable to determine the correct moral choice. How then to act? Any choice in which the probability that you'll act morally is less than 100% would be rationally untenable, as it would then sentence the actor to a fate of infinite pain. There would seem to be no solution to this quandry.

What does this mean, then? Well, either you can't be religious and rational OR, rational people need to choose a religion that has a non-binary eschatology. I know next to nothing about theology, but it seems like Catholicism solved this problem by inventing Purgatory. I'm not sure whether Protestants have a similar intermediate realm, but it must, as I know plenty of rational folks who are also devout Protestants.