BOOK I.

To Aristotle, a man certainly judged that persuasion, or "to persuade," original: "τὸ πείθειν" (to peithein) is nothing else for Rhetoricians than to create a certain opinion in someone's mind through probable speech. Other arts do indeed persuade; but, as Aristotle testifies in the Rhetoric, chapters 1 and 11, they do not persuade everyone. They only persuade those who know the principles of those specific arts. Nor do they persuade simply through probable arguments, but through the specific principles of the art itself.

II. THE DEFINITION OF RHETORIC, AND CONCERNING THE THREEFOLD

Once the goal of the Orator is known, it will be easy to construct a definition of Rhetoric. Indeed, arts ought to be defined by their end goal, just as sciences are defined by their subjects. For even if other things are mixed in, the end goal especially takes the place of the "form." In Aristotelian philosophy, the "form" provides the essential nature and definition of a thing. Therefore, Rhetoric is best defined by Aristotle as the Faculty of seeing in each case what happens to be conducive to persuasion. He says: Rhetoric is a power of observing in each thing the possible means of persuasion. original: "Ἡ Ῥητορική ἐστὶν δύναμις περὶ ἕκαστον τοῦ θεωρῆσαι τὸ ἐνδεχόμενον πιθανόν."

Furthermore, this definition, besides the goal which we said was to persuade, also reveals the DUTY of the Orator for the purpose of explaining the nature of Rhetoric more fully. This duty is to see whatever is fit for creating belief. It also reveals the SUBJECT MATTER, which is any thing insofar as it can be the subject of persuasion.

Understand, however, the COMMON SUBJECT MATTER to be any question, whether it is theoretical* original: "θεωρητική" (theoretikē), relating to knowledge and contemplation. and concerns knowledge, or practical* original: "πρακτική" (praktikē), relating to action.. Indeed, it sometimes happens in practice that an argument from a speculative science must be brought to an active conclusion. For example, in the past, Agathocles a had to show the Sicilians, and Sulpicius Gallus b the Romans, that eclipses happen in a natural order at fixed times. They did this so the army would not shrink from battle, terrified as if by a dire omen. This was done for the sake of an action. At other times, contrary to the view of Zabarella c Jacopo Zabarella was a 16th century logician who argued that rhetoric and logic differ in their subject matter., the orator has only knowledge as his proposal. For he will treat the architect of this world, the immortality of souls, and any mysteries of nature with a popular, emotional, and adorned style of speaking. He will draw many to his opinion whose doors a Philosopher would have knocked upon in vain with solid reasons alone. For this reason, Aristotle rightly makes the subject matter of Rhetoric each and every thing d. This was also the opinion of Gorgias of Leontini. Cicero subscribes to the same in his Oratorical Partitions and Topics.

But the PROPER subject matter of Rhetoric is a practical matter e, or one that is active.