The Complete Aristotle (eng.)

three elements: one class is very
rich, another very poor, and a third in a mean. It is admitted that
moderation and the mean are best, and therefore it will clearly be
best to possess the gifts of fortune in moderation; for in that
condition of life men are most ready to follow rational principle.
But he who greatly excels in beauty, strength, birth, or wealth, or
on the other hand who is very poor, or very weak, or very much
disgraced, finds it difficult to follow rational principle. Of
these two the one sort grow into violent and great criminals, the
others into rogues and petty rascals. And two sorts of offenses
correspond to them, the one committed from violence, the other from
roguery. Again, the middle class is least likely to shrink from
rule, or to be over-ambitious for it; both of which are injuries to
the state. Again, those who have too much of the goods of fortune,
strength, wealth, friends, and the like, are neither willing nor
able to submit to authority. The evil begins at home; for when they
are boys, by reason of the luxury in which they are brought up,
they never learn, even at school, the habit of obedience. On the
other hand, the very poor, who are in the opposite extreme, are too
degraded. So that the one class cannot obey, and can only rule
despotically; the other knows not how to command and must be ruled
like slaves. Thus arises a city, not of freemen, but of masters and
slaves, the one despising, the other envying; and nothing can be
more fatal to friendship and good fellowship in states than this:
for good fellowship springs from friendship; when men are at enmity
with one another, they would rather not even share the same path.
But a city ought to be composed, as far as possible, of equals and
similars; and these are generally the middle classes. Wherefore the
city which is composed of middle-class citizens is necessarily best
constituted in respect of the elements of which we say the fabric
of the state naturally consists. And this is the class of citizens
which is most secure in a state, for they do not, like the poor,
covet their neighbors’ goods; nor do others covet theirs, as the
poor covet the goods of the rich; and as they neither plot against
others, nor are themselves plotted against, they pass through life
safely. Wisely then did Phocylides pray—‘Many things are best in
the mean; I desire to be of a middle condition in my city.’
    Thus it is manifest that the best political community is formed
by citizens of the middle class, and that those states are likely
to be well-administered in which the middle class is large, and
stronger if possible than both the other classes, or at any rate
than either singly; for the addition of the middle class turns the
scale, and prevents either of the extremes from being dominant.
Great then is the good fortune of a state in which the citizens
have a moderate and sufficient property; for where some possess
much, and the others nothing, there may arise an extreme democracy,
or a pure oligarchy; or a tyranny may grow out of either
extreme—either out of the most rampant democracy, or out of an
oligarchy; but it is not so likely to arise out of the middle
constitutions and those akin to them. I will explain the reason of
this hereafter, when I speak of the revolutions of states. The mean
condition of states is clearly best, for no other is free from
faction; and where the middle class is large, there are least
likely to be factions and dissensions. For a similar reason large
states are less liable to faction than small ones, because in them
the middle class is large; whereas in small states it is easy to
divide all the citizens into two classes who are either rich or
poor, and to leave nothing in the middle. And democracies are safer
and more permanent than oligarchies, because they have a middle
class which is more numerous and has a greater share in the
government; for when there is no middle class, and the poor greatly
exceed in number, troubles arise, and the state soon comes to an
end. A proof of the superiority of the middle dass is that the best
legislators have been of a middle condition; for example, Solon, as
his own verses testify; and Lycurgus, for he was not a king; and
Charondas, and almost all legislators.
    These considerations will help us to understand why most
governments are either democratical or oligarchical. The reason is
that the middle class is seldom numerous in them, and whichever
party, whether the rich or the