Legitimacy refers to the rightfulness of a powerholder or system of rule. The term originated in controversies over property and succession, and was used to differentiate children born of a lawful marriage from those who were ‘illegitimate’. From thence the term entered political discourse via controversies over the rightful succession to the restored French throne after the Napoleonic period. However, questions about what makes government rightful have been a central issue of philosophical debate since the ancient Greeks, and in this sense the concept, if not the term, ‘legitimacy’ is as old as political philosophy itself. Its significance lies in the moral, as opposed to merely prudential, grounds for obedience which follow for subjects where power is rightfully acquired and exercised, and in the depth of allegiance which such political authorities can call upon in times of difficulty.
What, then, makes government legitimate? Most thinkers agree that a necessary condition is that power should be acquired and exercised according to established rules, whether these are conventionally or legally defined. However, legal validity cannot be a sufficient condition of legitimacy, since both the rules and the power exercised under them also have to be morally justifiable. Two broad criteria for moral justifiability can be distinguished: (1) political power should derive from a rightful source of authority; (2) it should satisfy the rightful ends or purposes of government. Most philosophical disputes about legitimacy take place either within or between these two broad positions; any adequate account of it must embrace both however.
The crisis of modernity as the crisis of the political: Towards a critique of the reason of the ethos
