Legitimacy is a modern concept that was unknown in the same form to ancient and medieval political thought. It gained prominence in debates over royal legitimacy during the wars of religion and reappeared in nineteenth-century dynastic legitimism. This history has led legitimacy to be treated either as a heteronomous foundation opposed to modern political autonomy or as a loose term for contesting legally constituted power. This critical-philosophical essay reformulates legitimacy through François Jullien’s concept of dé-coïncidence (de-coincidence). Through conceptual reconstruction and a genealogical reading of the relationship between religion, theology, law and politics, it distinguishes political religion which fuses the religious and the political from a theology of the political, which sustains a critical distance between them. The discussion shows that democracy cannot be reduced to legality, whilst legitimacy must not become a religious norm placed above the law. Legitimacy should operate as de-coincidence, ‘fissuring’ the tendency of law, social norms, conscience and religious normativity to close in upon themselves. Theology thereby gains public credibility not as a rival source of sovereignty but as a critical rationality connecting the primacy of conscience with society’s capacity for collective self-determination. The essay’s originality lies in arguing that democratic autonomy can be sustained only through the non-possession of power: power must be exercised and decisions must be made, yet power cannot be owned absolutely by the state, the majority, the individual or religion.