In this thesis, I defend John Rawls’s assertion that political liberalism does not use the concept of truth. I respond to objections from Joshua Cohen and David Estlund. I argue that Cohen fails to show that public reason needs a minimalist conception of truth, since individuals with a range of conceptions of moral truth can meet the requirements of public reason. I dispute Estlund’s argument that the liberal principle of legitimacy is merely insular. Estlund assumes that the claim that the liberal principle of legitimacy is reasonable is no different than the claim that the principle is acceptable to reasonable persons. I argue that this assumption is incorrect, and that therefore the liberal principle of legitimacy is justifiable on the grounds that it is reasonable. I argue that political liberals need not worry that doing without the concept of truth will undermine the semantic coherence or objectivity of political liberalism.