This paper focuses on the problem of justifying the normative claim to legitimacy and maintaining the stability of democratic political structures under conditions of cultural diversity. The author defines the problem in terms of its theoretical and practical implications and presents exegetical summaries of three philosophical solutions to it: Immanuel Kant’s attempt to ground a universalistic philosophy of morality on the assumption of the transcendental unity of practical reason, John Rawls’ idea for an “overlapping consensus,” and Jürgen Habermas’ discourse theoretical grounding of a deliberative model of democracy. The paper concludes with the argument that Habermas’ approach is conceptually more sophisticated and practically more relevant when compared with the other two, and, as such, it offers a more promising solution to the problem at hand.