People rarely revise their beliefs on issues they care about.  Even when confronted with strong counter-evidence, they usually manage to weasel out somehow.  When you encounter someone who has revised his beliefs, therefore, it’s tempting to conclude that he’s highly reasonable.  Apostates – people who abandoned a whole belief structure – smugly feed this temptation: “When the facts change, I change my mind.  What do you do, sir?”  As a serial apostate, I’ve often smugly fed this temptation myself.

When I listen to apostates, however, I’m usually struck by the flimsiness of their deconversion stories.  Why exactly did they change their minds?  A reasonable apostate would go through a process like:

1. I used to believe X, where X is something that at least sounds vaguely plausible.

2. But then I noticed a non-obvious but telling intellectual flaw in X.

3. I approached the best minds who believe X with my doubts, but none of them had a good response.

4. So I stopped believing X.

In practice, many apostasy stories discuss people rather than ideas: I had a falling-out with my fellow believers, so I stopped agreeing with them.  But even the idea-centric stories sound more like:

1. I used to believe X, where X is something that sounds silly.

2. But then I noticed an obvious and telling intellectual flaw in X.

3. I ignored the flaw for a while.

4. Then I finally woke up and stopped believing X.

My point here is not that people shouldn’t change their minds.  They totally should.  My point, rather, is that human irrationality is even more prevalent than it seems.  Most people are too irrational to change their minds on anything important.  But most people who change their minds on important issues nevertheless do so irrationally.