In moral and political philosophy, the social contract is an idea, theory or model that usually, although not always, concerns the legitimacy of the authority of the state over the individual. Conceptualized in the Age of Enlightenment, it is a core concept of constitutionalism, while not necessarily convened and written down in a constituent assembly and constitution.

A constitution is the aggregate of fundamental principles or established precedents that constitute the legal basis of a polity, organization or other type of entity, and commonly determines how that entity is to be governed.