Common Belief

A group of people has Common Belief’ of p’ when each person in the group believes each person in the group believes each person in the group believes [sic.] p’. This is independent of whether they personally believe p’.

E.g.: The Emperor’s New Clothes” is a story about Common Belief and its collapse: each townsperson believes everyone else believes everyone else believes [sic.] they can see the invisible fabric, up until the moment the kid shouts the King is naked, and everyone realizes everyone else is thinking the same thing.


Date
March 6, 2023