ABSTRACT

These epistemic overtones concerning our mutual information are not mere side-effects. They may steer further concrete actions. Some bystanders’ know­ ing that I know the road to Maximus’ location may lead them to rush off and warn the Emperor Commodus about this inquisitive Dutch visitor — while my knowing that they know I know may lead me to prevent them from doing just that. So epistemic overtones are ubiquitous and important, and we are good at computing them! In particular, we are well-attuned to fine differences in group knowledge. Everyone’s knowing individually that your partner is unfaithful is unpleasant, but shame explodes when you meet people and know they all know that they know.