Can rational people disagree? This episode of Rationally Speaking features guest Scott Aaronson. Scott is a professor of computer science at MIT and has written about "Aumann's Agreement Theorem," which is related to Bayesian probability theory and seems to imply that two people cannot rationally disagree after they've shared their opinions and information with each other. Julia and Scott discuss how to reconcile Aumann's theorem with real-world disagreements, and explore the disconcerting question: Why should you favor your own beliefs, just because they're yours?