This article has two primary objectives. First, it sets out the methodological argument that the conventional antinomy between normative and sociological approaches to questions of state legitimacy depends on a series of false constructions, and that normative and sociological – or specifically historical–sociological – analyses of states and the processes by which they obtain legitimacy can be (and ought to be) mutually reinforcing. This argument hinges on the claim that historical sociology should renounce some of its common presuppositions regarding the coercive functions of state power and reformulate itself as a normative social science, identifying and promoting models of statehood likely to obtain legitimacy in modern differentiated societies. Second, it sets out the more substantive argument that the legitimization of states can be observed both as an evolutionary or adaptive dimension of state formation and as a process of theoretical self-reflection in which the societies where states are located construct and refine the most adequate form for the transmission of the power they designate as political. In this respect, the article questions common assumptions about politics and legitimacy and makes a case for a change of paradigm in the analysis of these concepts. Through this change of paradigm, politics itself and the methods used for securing legitimacy for politics are constructed as abstracted articulations of a society’s own needs and exigencies. The article borrows elements from the systemic-functionalist sociology of Niklas Luhmann to develop the argument. In this context, the article also uses historical case studies to outline a theory of constitutions and constitutional rights. This theory explains how constitutions and constitutional rights help to generate legitimacy for states by enabling modern political systems, both normatively and functionally, to reflect and stabilize their position in society, to control the volume of politics in a society, and to elaborate socially adequate techniques for applying and restricting political power. The article concludes by suggesting that historical–sociological analyses of the functions of rights and constitutions can provide a key to proposing both normatively and sociologically founded models of legitimate statehood.