The "Art" of Rhetoric (1.3.5-1.3.9)

Each of the three kinds has a different special end, and as there are three kinds of Rhetoric, so there are three special ends. The end of the deliberative speaker Is the expedient or harmful; for he who exhorts recommends a course of action as better, and he who dissuades advises against it as worse; all other considerations, such as justice and injustice, honor and disgrace, are included as accessory in reference to this. The end of the forensic speaker is the just or the unjust; in this case also all other considerations are included as accessory. The end of those who praise or blame is the honorable and disgraceful; and they also refer all other considerations to these.

A sign that what I have stated is the end which each has in view is the fact that sometimes the speakers will not dispute about the other points. For example, a man on trial does not always deny that an act has been committed or damage inflicted by him, but he will never admit that the act is unjust; for otherwise a trial would be unnecessary. Similarly, the deliberative orator, although he often sacrifices everything else, will never admit that he is recommending what is inexpedient or is dissuading from what is useful; but often he is quite indifferent about showing that the enslavement of neighboring peoples, even if they have done no harm, is not an act of injustice.[*] Similarly, those who praise or blame do not consider

From what has been said it is evident that the orator must first have in readiness the propositions on these three subjects.[*] Now, necessary signs, probabilities, and signs are the propositions of the rhetorician; for the syllogism universally[*] consists of propositions, and the enthymeme is a syllogism composed of the propositions above mentioned.

Again, since what is impossible can neither have been done nor will be done, but only what is possible, and since what has not taken place nor will take place can neither have been done nor will be done, it is necessary for each of the three kinds of orators to have in readiness propositions dealing with the possible and the impossible, and as to whether anything has taken place or will take place, or not.

Further, since all, whether they praise or blame, exhort or dissuade, accuse or defend, not only endeavor to prove what we have stated, but also that the same things,