Cornelii Valerii Ultraiectini In universam benedicendi [sic] rationem tabula, summam artis rhetoricae complectens

Why art is needed if precepts do not make one eloquent.

The precepts of art are needed, first, to judge not only the writings of eloquent men whom we propose to imitate, but also our own exercises; second, to aid nature, which, if it is not excellent, can still be corrected to some degree; and, as Cicero writes, although some who are endowed with great talents achieve a wealth of speaking without a system, art is nevertheless a more certain guide than nature. For what you achieve relying only on natural light, you will accomplish much better and more certainly through art.

The office, or power and faculty, of the orator.

Three things must be accomplished by the orator.

To teach is a duty, to delight is an honorarium, to move is necessary for the orator.

An orator is a good man skilled in speaking.

The end is to persuade that which is proposed: to which ultimate end one arrives by speaking well.

The office of the orator is to speak about any proposed subject in a way suited for persuasion, which is accomplished by teaching, delighting, and swaying; the first of these is for necessity, the second for pleasantness, and the third for victory. The orator will achieve these more easily if he is considered a good man.

The end is to persuade by speech and to sway the minds of the listeners. Of these three things that the orator must accomplish, the first is shared with dialecticians and philosophers, which is done through clear exposition and argumentation, especially in a subtle or attenuated style of speaking; the second is shared with sophists, which is done by this and by elocution in a generally moderate form of speech; the third is proper to the orator, which is accomplished mostly by moving emotions in a vehement and grave style of speaking. The instrument of the rhetorical art is that copious, ornate, and continuous speech which is accustomed to be delivered either in the senate, or to a judge, or to the people (for the speech of philosophers and dialecticians is usually concise and interrupted by mutual interrogations, such as the conversation of philosophers in debates and dialogues). The orator borrows corrected and Latin speech from Grammar,

Regarding the styles of speaking, see the laws below under the chapter, On Elocution.

The faculty of moving minds is the foremost of the orators.

The instrument of rhetoric is the speech of orators. The speech of philosophers is conversation.

What is the difference between grammar, dialectic, and rhetoric.