This chapter develops a conception of justificatory stability as a normative ideal of stability. Justificatory stability arises from citizens’ reflective endorsement of their political system. When citizens adopt support for their political system as a highest-order end, it then governs their pursuit of their other ends, such that temptations to cheat on their political obligations, or to subordinate those obligations to their moral or religious obligations, are overridden by their commitment to the political order. Justificatory stability resolves inadequacies in other conceptions of political stability to which it is contrasted—specifically “brute force” stability and “modus vivendi” stability. The chapter concludes with a discussion of the feasibility of justificatory stability as an ideal.