In this article my aim is to address the issue of the public justification of political liberalism from the perspective of moral epistemology. I begin showing that a strictly political account of liberal legitimacy is hostage of tensions that are intrinsic to the justificatory framework itself. On the one hand, an adequate conception of justice should grant the required normative force thanks to the appeal to compelling justificatory arguments. On the other hand, a strictly political version of liberalism is characterized by a major focus on the actual circumstances of justice and on the acknowledgment of the fact of pluralism. Rawls main goal in Political Liberalism, for example, is to provide a full justification for a strictly political conception of liberalism starting from the “here and now” of the contemporary political societies. Rawls believes that his version of political liberalism, being neutral with regard to metaphysical and epistemological disputes, can avoid dilemmatic outcomes.
In the second part of the article, I argue, pace Rawls, that political liberalism cannot be robust vis-à-vis different theories of justification, because it is required that as theorists we take a stance regarding the epistemological framework we employ while developing a specific theory of political legitimacy. My proposal is that a moderate approach in moral epistemology expresses the best scheme available to us - as moral agents constrained by the limit of our rationality - for establishing a normatively binding, and yet realistic, procedure of justification for political institutions and practices. An epistemic moderate account can be described around four fundamental benchmarks: (1) a doxastic presupposition that highlights the fundamental deliberative role played by moral agents as they are the last authority for determining which principles are indeed compatible with their wide set of beliefs; (2) a fallibilist account of moral knowledge; (3) a coherentist theory of epistemic justification and (4) a moderate account of objectivity according to which the objectivity of the moral discourse rests on the correctness-apt deliberative procedure we produce as moral agents and that involves some correctness criteria that are publicly justified through the exchange of reasons among reasonable citizens.