The constitution of a political economy is not a fixed constellation of relationships but a set of principles governing which relative positions and transformations are feasible under the existing constitutional arrangements. Constitutional principles imply that persistence and change are closely intertwined: a degree of persistence ensures the identity and stability of a political economy, while openness to transformation is necessary to allow resilience vis-à-vis shocks and adjustment to societal change. Each economic body is identified by a particular division of labour, representation of interdependencies, and dispositions of individuals and groups in the economy. Dispositions and interests are also central in the constitution of the political body, which leads to a definition of systemic interest and of the range of variation within which a given systemic interest can accommodate different constellations of partial interests. This conception of political economy makes principles of economic ordering essential to the life of the polity, and acknowledges the existence of political alliances or conflicts arising from division of labour between centres of agency in the economic sphere. The consideration of matches and mismatches between the two spheres opens a line of investigation that is central to understanding the history and prospects of political economies.