[O]ligarchy, strictly speaking, is a regime "in which a rich minority rules for the advantage of the rich minority and in which the people composing that political society are ranked... because the ruling principle of that regime is the principle of natural inequality." Aristotle called it a deviant form of aristocracy (in the same way that tyranny is a deviant form of monarchy), and in practical terms, it exhibits its form through excessive concentrations of property in the hands of a few, the reservation of education to the elite, and the organization of government to serve the purposes of the oligarchs.