The word "converge" has always applied to market responses to new info. Find a news event (e.g., WMT Oct 13-14) and look at the second or minute level movements near that event. It's qualitatively quite similar to Aaronson's theorem.
so, just IMO, a perfectly rational actor should be emotionless, at least on the matter at hand. any kind of emotional tendency would skew their reasoning.
to add to what you said more above, about those fruitful discussions: i would bet that the people you had those fruitful discussions with have had another common characteristic. namely, they did not have much personal stake in the issue you were discussing. when people approach a discussion with only a desire to learn and improve their opinions, they can indeed have a quality discussion.
ultimately, i don't believe such neat separation of rational and irrational can ever work (aside from sometimes being a useful approximation). which is why i asked those silly questions - how can a rational actor want something, without wanting it? i find the concept very contradictory, borderline useless.
edit - i think i have to back down a bit, or maybe just clarify, dunno. i maybe get what you meant. people that appreciate rationality will tend to be better discussion partners even if they are personally affected. but it will be much harder...
Nope. A perfectly rational actor should have unskewed reasoning, yes, but you can (in principle) achieve that by making your emotions not skew your reasoning rather than by throwing your emotions away.