"The words constitution and government have the same meaning, and the government, which is the supreme authority in states, must be in the hands of one, or of a few, or of the many. The true forms of government, therefore, are those in which the one, or the few, or the many, govern with a view to the common interest; but governments which rule with a view to the private interest, whether of the one or of the few, or of the many, are perversions. Of forms of government in which one rules, we call that which regards the common interests, monarchy; that in which more than one, but not many, rule, aristocracy (and it is so called, either because the rulers are the best men, or because they have at heart the best interests of the state and of the citizens). But when the citizens at large administer the state for the common interest, the government is called a polity. And there is a reason for this use of language.
"Of the above-mentioned forms, the perversions are as follows: of monarchy, tyranny; of aristocracy, oligarchy; of polity, democracy. For tyranny is a kind of monarchy which has in view the interest of the monarch only; oligarchy has in view the interest of the wealthy; democracy, of the needy: none of them the common good of all. Tyranny, as I was saying, is monarchy exercising the rule of a master over the political society; oligarchy is when men of property have the government in their hands; democracy, the opposite, when the indigent, and not the men of property, are the rulers....Then ought the good to rule and have supreme power? But in that case everybody else, being excluded from power, will be dishonored. For the offices of a state are posts of honor; and if one set of men always holds them, the rest must be deprived of them. Then will it be well that the one best man should rule? Nay, that is still more oligarchical, for the number of those who are dishonored is thereby increased....The discussion of the first question shows nothing so clearly as that laws, when good, should be supreme; and that the magistrate or magistrates should regulate those matters only on which the laws are unable to speak with precision owing to the difficulty of any general principle embracing all particulars."
- Aristotle, Politics