How to Argue by Barry Eisler
The strangest thing about the low quality of Internet argument is that effective argument isn't really so difficult. Sure, not everyone can be Clarence Darrow, but anyone who wants to be at least competent at argument can do it. Here are a few guidelines.
Both participants listen attentively to each other; neither tries to promote himself by pleasing the other; both are obviously enjoying an intellectual workout; neither spoils the evening's peaceable air by making a speech or letting disagreement flare into anger; they do not make tedious attempts to be witty. They observe classic conversational etiquette with a self-discipline that would have pleased Michel de Montaigne, Samuel Johnson, or any of a dozen other old masters of good talk whom Miller cites as authorities.