Perhaps necessarily, the oldest meaning of citizenship, participation in political self-governance, has survived in the modern world only in greatly modified form. The word ‘citizen’ derives from the Latin civis or civitas, meaning a member of an ancient city-state, preeminently the Roman republic; but civitas was a Latin rendering of the Greek term polites, a member of a Greek polis. Innumerable scholars have told how a renowned resident of the Athenian polis, Aristotle, defined a polites or ‘citizen’ as someone who rules and is ruled in turn, making ‘citizenship’ conceptually inseparable from political governance. Though most inhabitants of Athens, including the foreigner Aristotle himself, were ineligible to participate in citizenship thus understood, this ideal of citizenship as self-governance has often served since as an inspiration and instrument for political efforts to achieve greater inclusion and democratic engagement in political life. It continues to play that role in modern political discourse.