This essay is an entry in the Handbook for Democracy, a catalog of power techniques used by elites to exercise control and undermine the democratic self-government of the people.
The first lesson that must be learned to have a healthy democracy is this: there are those in society who, intentionally or not, are enemies of democracy. There is always an elite that believes itself better able to rule than everyone else, that holds self-government by the people in contempt, and that tries to acquire predominance of control through force, fraud, ideology, money, and other forms of power. Maintaining a vibrant democracy that creates good lives for all its people requires that the common people use power to constrain the authoritarian-minded, control-seeking elite.
Aristotle, who had a habit of categorizing everything, classified governments according to which part of society ruled: one person, an elite few, or the many common people, and whether that class governed in its own interest or in the interest of all. He believed that there could be a good form of government by one person, led by a wise and gentle ruler, and he called it monarchy; he called the bad form of rule by one person tyranny, when the ruler governed arbitrarily according to uncontrolled impulse. The good form of government by an elite, consisting of the best and most experienced people that society had to offer, was aristocracy; the bad form was oligarchy, government by the avaricious, self-interested wealthy few. Government by the common people, or the demos, was called democracy, and Aristotle thought, as did many other premodern political thinkers, that it was an unstable, impulsive, and incompetent form of government. Aristotle called the good form of popular government polity, but it was a mixed government that had a role for all classes, so the interests of all could be expressed. It served as inspiration for later civic republican thinkers. Aristotle also believed that an economy that supported a strong, large middle class was best: too much inequality put the rich and the poor at odds, almost as if they belonged to different societies, for their interests and experiences are too different to be reconciled.
The point is that Aristotle was right: there are different classes in society, they have fundamentally different interests, and they inevitably enter into politics. If we are to defend the self government of all the people, then we must prevent the dominance of rule by an elite few or a single person. Over the last forty years the oligarchs have been gathering more and more wealth, privileges, and power to themselves, and the principle political challenge of our time is to prevent and reverse this trend.