The Complete Aristotle (eng.)

many, are perversions. For the
members of a state, if they are truly citizens, ought to
participate in its advantages. Of forms of government in which one
rules, we call that which regards the common interests, kingship or
royalty; 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 by the generic name—a constitution. And there is a reason
for this use of language. One man or a few may excel in virtue; but
as the number increases it becomes more difficult for them to
attain perfection in every kind of virtue, though they may in
military virtue, for this is found in the masses. Hence in a
constitutional government the fighting-men have the supreme power,
and those who possess arms are the citizens.
    Of the above-mentioned forms, the perversions are as follows: of
royalty, tyranny; of aristocracy, oligarchy; of constitutional
government, 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.
VIII
    But there are difficulties about these forms of government, and
it will therefore be necessary to state a little more at length the
nature of each of them. For he who would make a philosophical study
of the various sciences, and does not regard practice only, ought
not to overlook or omit anything, but to set forth the truth in
every particular. 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. And here arises the first of our difficulties, and it
relates to the distinction drawn. For democracy is said to be the
government of the many. But what if the many are men of property
and have the power in their hands? In like manner oligarchy is said
to be the government of the few; but what if the poor are fewer
than the rich, and have the power in their hands because they are
stronger? In these cases the distinction which we have drawn
between these different forms of government would no longer hold
good.
    Suppose, once more, that we add wealth to the few and poverty to
the many, and name the governments accordingly—an oligarchy is said
to be that in which the few and the wealthy, and a democracy that
in which the many and the poor are the rulers—there will still be a
difficulty. For, if the only forms of government are the ones
already mentioned, how shall we describe those other governments
also just mentioned by us, in which the rich are the more numerous
and the poor are the fewer, and both govern in their respective
states?
    The argument seems to show that, whether in oligarchies or in
democracies, the number of the governing body, whether the greater
number, as in a democracy, or the smaller number, as in an
oligarchy, is an accident due to the fact that the rich everywhere
are few, and the poor numerous. But if so, there is a
misapprehension of the causes of the difference between them. For
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. But as a fact the rich are few and the poor many;
for few are well-to-do, whereas freedom is enjoyed by an, and
wealth and freedom are the grounds on which the oligarchical and
democratical parties respectively claim power in the state.
IX
    Let us begin by considering the common definitions of oligarchy
and democracy, and what is justice oligarchical and democratical.
For all men cling to justice of some kind, but their conceptions
are imperfect and they do not express the whole idea. For example,
justice is thought by them to be, and is, equality, not. however,
for however, for but only for equals. And inequality is thought to
be, and is, justice; neither is this for all, but only for
unequals. When the persons are omitted, then men judge erroneously.
The reason is that they are passing judgment on themselves, and
most people are bad judges in their own case. And whereas justice
implies a relation to persons