The Impossibility of a Bayesian Liberal?

Abstract

Aumann’s theorem states that no individual should agree to disagree under a range of assumptions. Political liberalism appears to presuppose these assumptions with the idealized conditions of public reason. We argue Aumann’s theorem demonstrates they nevertheless cannot be simultaneously held with what is arguably political liberalism’s most central tenet. That is, the tenet of reasonable pluralism, which implies we can rationally agree to disagree over conceptions of the good. We finish by elaborating a way of relaxing one of the theorem’s axioms that arguably lends itself to a coherent account of political liberalism, namely the condition of indexical independence.

Keywords: agreeing to disagree, political liberalism, impartiality, political philosophy, rational choice theory

JEL Classification: D70, D80