BOOK VIII: THE KINDS OF FRIENDSHIP
From THE NICOMACHEAN ETHICS
Aristotle
x. The different kinds of constitution
There are three kinds of "political" constitution, and an equal number of perversions or corruptions of them. The constitutions are monarchy, aristocracy, and thirdly the kind that is based on a property qualification (timema), which it seems natural to call a timocracy, although most people usually call it a polity. Of these the best is monarchy and the worst timocracy. The perversion of monarchy is tyranny. Both are forms of one-man rule, but they are vastly different. The tyrant regards his own interest, but the king regards that of his subjects. For a ruler is not a king unless he has independent means and is better off in every way than his subjects are; and such a person needs nothing further, and therefore will study not his own advantage but that of his subjects (for anyone who lacks these qualities will be a sort of titular king). Tyranny is the exact opposite of this sort of rule, because the tyrant pursues his own good. It is more obvious in the case of tyranny that it is the worst of the perversions; and the worst is the opposite of the best.
Change of constitution
takes place from monarchy into tyranny, because tyranny is the corruption
of monarchy: so a bad king becomes a tyrant. From aristocracy the change
is into timocracy, and it is due to the corruptness of ministers, who
distribute the resources of the state without regard to merit, and keep
all or most of the benefits for themselves, and confine public appointments
to the same persons, because they pay most regard to wealth. Thus it is
a few bad men, instead of the best, that hold the power. From timocracy
the change is into democracy, since they are next-door neighbours; because
timocracy too has as its object rule by the people, all who satisfy the
property qualification being equal. The least bad is democracy, because
it departs little from the form of polity. These are the commonest changes
of constitution, because they involve the smallest and easiest transitions.