Kitap 1
4.12
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.
4.13
Moreover, with reference to acts of legislation, it is useful not only to understand what form of government is expedient by judging in the light of the past, but also to become acquainted with those in existence in other nations, and to learn what kinds of government are suitable to what kinds of people. It is clear, therefore, that for legislation books of travel are useful, since they help us to understand the laws of other nations, and for political debates historical works.This rendering, although convenient, hardly represents the Greek, which, literally translated, is the investigations of those who write about human actions (cf. ἱστορικός, 4.8). All these things, however, belong to Politics and not to Rhetoric.
4.13
Such, then, are the most important questions upon which the would-be deliberative orator must be well informed. Now let us again state the sources whence we must derive our arguments for exhortation or discussion on these and other questions.
