Where some people are very wealthy and others have nothing, the result will be either extreme democracy or absolute oligarchy, or despotism will come from either of those excesses.
The right constitutions, three in number- kingship, aristocracy, and polity- and the deviations from these, likewise three in number - tyranny from kingship, oligarchy from aristocracy, democracy from polity.
What has soul in it differs from what has not, in that the former displays life. Now this word has more than one sense, and provided any one alone of these is found in a thing we say that thing is living. Living, that is, may mean thinking or perception or local movement and rest, or movement in the sense of nutrition, decay and growth. Hence we think of plants also as living, for they are observed to possess in themselves an originative power through which they increase or decrease in all spatial directions.
The real difference between democracy and oligarchy is poverty and wealth. Wherever men rule by reason of their wealth, whether they be few or many, that is an oligarchy, and where the poor rule, that is a democracy.
These two rational faculties may be designated the Scientific Faculty and the Calculative Faculty respectively; since calculation is the same as deliberation, and deliberation is never exercised about things that are invariable, so that the Calculative Faculty is a separate part of the rational half of the soul.
There is an error common to both oligarchies and to democracies: in the latter the demagogues, when the multitude are above the law, are always cutting the city in two by quarrels with the rich, whereas they should always profess to be maintaining their cause; just as in oligarchies the oligarchs should profess to maintain the cause of the people, . .