This month, Patheos asked bloggers to contribute to a Public Square symposium on the question “Is Faith Rational, Irrational, or Arational?” Since I used to work teaching Bayesian statistics for the Center for Applied Rationality and I’m now a statistician for FiveThirtyEight, I’m coming down firmly on the “Rational” side of this trilemma.
But “rational” may not mean what you think. You’re selling rationality short if you think of it as just comprising systems of inductive proof, like mathematics, where you start with axioms and extend yourself out cautiously, only accepting theorems that have been rigorously proven, leaving everything else as “conjecture.” If you’re asking people who adhere to different faiths to meet this level of rigor, don’t be surprised when they don’t pass your test. But this would be too high a bar for belief in almost any domain of action.
In one interview I gave after my conversion, the Christian radio host interviewing me appealed to this level of rigor and argued that atheists really should call themselves agnostics. “How can they say that they know for sure that God doesn’t exist?” he asked.
It’s true, most atheists don’t claim to know that God exists in the same way that they know, say, the law of the excluded middle, but they’re still perfectly justified in claiming the name of atheists. After all, I don’t believe that there’s life on Mercury, but I’ve never been over to the planet to check — I don’t even have relevant qualifications in the area, but it would be a lie to say I’m agnostic on the question.
A rational belief is the way you lean, based on the evidence you have (and with a bit of due diligence to make sure that the evidence you have is the evidence you need). It’s the outcome you’d bet on, if someone gave you the chance. It includes a lot of beliefs that are more working hypotheses than proofs. And it’s not too far from the scientific method.
In Arcadia (my favorite non-Shakespeare play), two of the characters are discussing a literature professor’s thinly sourced hypothesis:
Valentine: It may all prove to be true.
Hannah: It can’t prove to be true, it can only not prove to be false yet.
Valentine: Just like science.
My faith and my conversion are “just like science” in the same way. God and Catholicism turned out to be my best working hypothesis when I poked deeper and deeper into the question of what morality was and how we had access to a transcendent truth (besides math). Changing my mind wasn’t so much a choice as a recognition that my belief had shifted. I didn’t necessarily believe in God with 99% confidence, but He was my best hypothesis, and it would be a lie to pretend to be agnostic at that point.
Since converting and beginning to practice the faith, I’ve run into more small pieces of evidence, but they’re not the kind of thing I can upload to ArXiv or submit to a peer reviewed journal. I still read theology, and sometimes I run into something interesting that shores up my confidence in the coherence of the faith, but a lot of my evidence is much more circumstantial. Allowing God a space in my life, means receiving a lot of small graces, whether they come in the form of comfort, contrition, or even righteous sorrow.
These small touches wouldn’t have been enough to push me over the threshhold of belief, but they do help to root me in my faith, just as simply observing the sun rise every day doesn’t prove it will rise tomorrow, but it sure weights your belief on the question.
If you want the chance to change someone else’s mind (or to make sure you’ve given yourself the chance to notice if you’re wrong), making a rational conversion doesn’t just mean reading over Aquinas’s Five Proofs for God but about asking yourself how you’d notice if you’ve been living in the world where Catholicism is true (or Hinduism or atheism or anything else) and whether there’s anything you’d like to read or questions you’d like to ask in order to get your bearings.