Aristotle, Rhetoric
J. H. Freese, Ed.

[12] With a view to the safety of the State, it is necessary that the orator should be able to judge of all these questions, but an understanding of legislation is of special importance, for it is on the laws
that the safety of the State is based. Wherefore he must know how many forms of government there are; what is expedient for each; and the natural causes of its downfall, whether they are peculiar to the particular form of government or opposed to it. By being ruined by causes peculiar to itself, I mean that, with the exception of the perfect form of government, all the rest are ruined by being relaxed or strained to excess. Thus democracy, not only when relaxed, but also when strained to excess, becomes weaker and will end in an oligarchy; similarly, not only does an aquiline or snub nose reach the mean, when one of these defects is relaxed, but when it becomes aquiline or snub to excess, it is altered to such an extent that even the likeness of a nose is lost.