When dealing with trolls, whether on the Internet or in Real Life, no matter how absolutely damn sure you are of your point, you have no time to unravel their bullshit for what it is, and if you try it you will only bore your audience and exhaust their patience. Debates aren't battles of truth: there's publishing papers and articles for that. Debates are battles of status.

I agree. There's also the scenario where you're talking to a reasonable person for the purpose of figuring out the truth better than either of you could do alone. That's useful, and it's important to be able to distinguish that from debating with trolls for the purpose of gaining status. Trolls can be recognized by how often they use rhetoric that obviously isn't truth-seeking, and Schopenhauer is very good for that.

Well, actually, on the Internet you never gain status by debating with trolls. Even if I win an argument, I lose status to the extent my behavior justifies the conclusion "Tim wastes time posting to (LessWrong|SlashDot|whatever) instead of doing anything useful."

My ability to identify and stonewall trolls varies. Sometimes I catch them saying something silly and refuse to continue unless they correct themselves, and that stops the time-waste pretty quickly. Sometimes I do three-strikes-and-your-out, and the time-waste stops reasonably soon. Sometimes it takes me a long time to figure out if they're a troll, especially if they're hinting that they know something worthwhile. I wish I had a more stable rule of thumb for doing this right. Any suggestions?