He distinguished three kinds of eloquence: the deliberative, the demonstrative, and the judiciary. The deliberative is employed to exhort those who deliberate in taking a part in war, in peace, etc.; the demonstrative, to show that which is worthy of praise or blame; the judiciary, to persuade, absolve, condemn, etc.
He afterwards treats of the manners and passions with which all orators should be acquainted.
He examines the proofs which should be employed in these three species of eloquence, and finally he treats of elocution, without which all would languish. He recommends metaphors, provided they are just and noble; and, above all, he requires consistency and decorum.
All these precepts breathe the enlightened precision of a philosopher, and the politeness of an Athenian; and, in giving the rules of eloquence, he is eloquent with simplicity.
It is to be remarked, that Greece was the only country in the world in which the laws of eloquence were then known, because it was the only one in which true eloquence existed.
The grosser art was known to all men; sublime traits have everywhere escaped from nature at all times; but to rouse the minds of the whole of a polished nation—to please, convince, and affect at the same time, belonged only to the Greeks.
The Orientals were almost all slaves; and it is one of the characteristics of servitude to exaggerate everything. Thus the Asiatic eloquence was monstrous. The West was barbarous in the time of Aristotle.
True eloquence began to show itself in the time of the Gracchi, and was not perfected until the time of Cicero. Mark Antony, the orator Hortensius, Curion, Cæsar, and several others, were eloquent men.
This eloquence perished with the republic, like that of Athens. Sublime eloquence, it is said, belongs only to liberty; it consists in telling bold truths, in displaying strong reasons and representations. A man often dislikes truth, fears reason, and likes a well-turned compliment better than the sublimest eloquence.
Cicero, after having given the examples in his harangues, gave the precepts in his "Book of the Orator"; he followed almost all the methods of Aristotle, and explained himself in the style of Plato.