Twelve Virtues of Rationality
yudkowsky.net
yudkowsky.net
More importantly, I'm almost positive that he could have expressed himself more clearly and less ambiguously. This essay has too many words and not enough content.
I think I see what he means, but the expected payoff from having people waving irons in your face is always non-positive, so it doesn't support his argument - ie. if you're rational you should always fear an iron approaching your face.