Authoritarianism is a political system characterized by the rejection of political plurality, the use of strong central power to preserve the political status quo, and reductions in democracy, separation of powers, civil liberties, and the rule of law. Authoritarian regimes may be either autocratic or oligarchic and may be based upon the rule of a party, the military, or the concentration of power in a single person. States that have a blurred boundary between democracy and authoritarianism have sometimes been characterized as "hybrid democracies", "hybrid regimes" or "competitive authoritarian" states.
The political scientist Juan Linz, in an influential 1964 work, An Authoritarian Regime: Spain, defined authoritarianism as possessing four qualities: