I've made no secret of the fact that I'm not a big fan of the principle of charity—often defined as the rule that you should interpret other people's arguments on the assumption that they are not saying anything stupid.

As far as I understand, the Principle of Charity is defined differently; it states that you should interpret other people's arguments on the assumption that these people are arguing in good faith. That is to say, you should assume that your interlocutor honestly believes in everything he's saying, and that he has no ulterior motive beyound getting his point across. He may be entirely ignorant, stupid, or both; but he's not a liar or a troll.

This principle allows all parties to focus on the argument, and to stick to the topic at hand -- as opposed to spiraling into the endless rabbit-holes of psychoanalyzing each other.