I argue against Rawls’s freestanding conception of liberalism. On my view, the moral foundation of liberalism can be defended in one of three ways: (1) as a conception one accepts as a result of one’s affirmation of political liberalism, (2) as a conception one must affirm as a presupposition for political liberalism, or (3) as a philosophical truth about practical reason and persons. The first option makes it impossible to distinguish a moral consensus from a modus vivendi. The second renders the moral foundation of liberalism dogmatic because it affirms a moral foundation for which no justification is provided. Since there are good reasons for rejecting (1) and (2), that leaves option (3). I argue that (3) should be the preferred option for liberals who advance liberalism as a political doctrine with a moral foundation.