The persuasive means of a rhetorical speech are of three kinds. One party is situated on the moral character of the speaker, another on disposing the hearer accordingly, and a third on the speech itself, in so far as it proves or seems to prove.
It is by means of the moral character of the speaker, when the speech is so spoken as to render the speaker credible; for we believe sooner and in a greater degree the virtuous, generally in everything, but in matters where we are not certain or there is room for dispute, our confidence is absolute.
And this ought to come about on account of the speech itself and not by what we think of the speaker’s character beforehand. For it is not the case, as some writers do in their text books of rhetoric, that the rectitude of the speaker does not contribute at all to his power of persuasion, wherefore they did not include it into the art, but perhaps, we might say, the moral character of the speaker plays a leading part in persuasion.
By means of the audience, when they are emotionally affected by the speech; for we do not judge the same when we are pained or pleased, in love or filled with hate, since, as we have said, nowadays those who are concerned with rhetoric direct their efforts only towards producing these feelings.
Finally, persuasion is produced by the speech itself, when we prove by possible arguments with regard to each case that our admission is true or plausible.
Bibliography: Aristotle, Art of Rhetoric (1356a.1 to 1356a.20)
Translation: George Kotsalis