Thank you to Justis Mills for proofreading and feedback. This post is also available on LessWrong. Aumann's agreement theorem is a family of theorems which say that if people trust each other and know each other's opinions, then they agree with each other. Or phrased another way, if people maintain trust with each other, then they can reach agreement. (And some variants of the theorem, which take computational factors into consideration, suggest they can do so quite rapidly.)
> Thus, "disagreement" comes to connote (or maybe even denote), "difference in opinion between people who don't trust each other" rather than simply "difference in opinion".
According to the way rationalists seem to define Aumann agreement, this isn't right; we might trust one another but still have radically different priors.
> Thus, "disagreement" comes to connote (or maybe even denote), "difference in opinion between people who don't trust each other" rather than simply "difference in opinion".
According to the way rationalists seem to define Aumann agreement, this isn't right; we might trust one another but still have radically different priors.