Robin Hanson and I have our fair share of philosophical disagreements. But the longer I stayed at the Social Philosophy and Policy conference, the more I kept thinking, “These people desperately need a strong dose of Hanson.” To be specific:

1. Few philosophers seemed to have integrated the basic Bayesian lesson that any argument for X that is less convincing than expected implies that you should reduce your probability that X is true. Instead, philosophers seem to think that any logically valid argument from plausible premises that implies X strengthens the case for X. It doesn’t.

2. Few philosophers attach any epistemological weight to the fact that other smart, well-informed people radically disagree with them. Of course, the fact of disagreement does not imply that you’re wrong, but it’s got to raise the probability. Yet over the course of a three-day conference, I don’t recall a single instance where a philosopher seemed troubled by his failure to persuade his peers. If anything, disagreement made the typical philosopher more confident than he was to start.

Closing thought: At risk of offending two disciplines at once, the main problem with philosophy is that it is too much like law: A field where people are more concerned about winning arguments than learning about the world. Don’t they know that if one of us finds the truth, we’re all winners? 🙂