“[…] we are accustomed to judging the truth of a claim by the moral status of the group making the claim.”

That’s Tyler Cowen speaking of “Climategate” in his post “The limits of good vs. evil thinking.” Normally I would put something like this in a links post, but “The limits of good vs. evil thinking” is so good that I’m emphasizing it with an independent post.

The major problem is that sometimes people we perceive as morally palatable can make untruthful or not optimally useful claims, while the opposite—people we perceive as morally unpalatable can make truthful or optimally useful claims—can also occur. Notice that I’m intentionally not providing examples of either phenomenon. As Paul Graham says in the notes to “What You Can’t Say:”

The most extreme of the things you can’t say would be very shocking to most readers. If you doubt that, imagine what people in 1830 would think of our default educated east coast beliefs about, say, premarital sex, homosexuality, or the literal truth of the Bible. We would seem depraved to them. So we should expect that someone who similarly violated our taboos would seem depraved to us.

If I said this kind of thing, it would be like someone doing a cannonball into a swimming pool. Immediately, the essay would be about that, and not about the more general and ultimately more important point.

The more important point is about avoiding ad hominem attacks and being able to consider claims independently of the person making the claims in some circumstances. As Cowen says, this is really hard.