I’ve recently made the blogoworld acquaintence of a character called Lubo? Motl, a string theorist at Harvard who has decided he has sufficient expertise to weigh in on the issue of climate change.

There is nothing wrong with doing this. All of us are entitled to have opinions on important public policy questions, and he should be thus praised for taking a stand. But he does it in a way that illustrates much that is wrong with political discourse. Here’s my favorite recent example, on the blog of British climate researcher William Connolley:

Sorry to be candid, but as far as this debate goes, all of you are dishonest and intellectually limited political activists.

This is it, in a nutshell. Lumo thinks that if you believe that we need to reduce greenhouse gas emissions because of climate change, then you are venal, or stupid, or both.

He’s not alone in doing this. In fact, this is a style of rhetoric common to talk radio and the blogosphere, and represents a common way of thinking and talking about all sorts of political and policy debates. It’s frankly intellectually lazy. It allows one to dismiss the arguments of one’s opponents without ever having to take them seriously. But in any sufficiently interesting political or policy debate, as I discussed elsewhere recently, there are sincere and reasonable people on both sides.

That doesn’t mean that some of your opponents aren’t venal and stupid, and that you shouldn’t call them on it. But if you don’t recognize two other things, you’re missing the boat. If you don’t recognize the venal and stupid people on your own side of the debate, you’re not paying sufficient attention, because they almost certainly are there. (Note to Lumo: you need to give Michael Crichton a closer read. Note to all those enthusiastic greenhouse gas reduction advocates who emailed me Ross Gelbspan’s hurricane piece: You shouldn’t be quite so attached to Gelbspan.) And if you aren’t seeking out and trying to understand the reasonable people on the other side of the debate, you’re not thinking the question through very well.