My dissertation brings together debates about the significance of reasonable disagreement for epistemology and political philosophy. I argue for a new view of the epistemic significance of peer disagreement. I show that this view, in combination with the correct understanding of liberal citizenship, leads to an important challenge to political liberalism: the requirements of citizenship are in tension with the justification of citizens’ religious, moral, and philosophical views. This challenge can be met, I propose, if we conceive of people’s fundamental convictions as acceptances rather than beliefs.