Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
Consequently those who, although holding the same general view of rhetoric, have regarded it as the power of persuasion by speaking, pride themselves on their greater exactness of language. This definition is given by Gorgias, in the dialogue [*](Gorg. p. 452 E. ) mentioned above, under compulsion from the inexorable logic of Socrates. Theodectes agrees with him, whether the treatise on rhetoric which has come down to us under his name is really by him or, as is generally believed, by Aristotle. In that work the end of rhetoric is defined as the leading of men by the power of speech to the conclusion desired by the orator.
But even this definition is not sufficiently comprehensive, since others besides orators persuade by speaking or lead others to the conclusion desired, as for example harlots, flatterers and seducers. On the other hand the orator is not always engaged on persuasion, so that sometimes persuasion is not his special object, while sometimes it is shared by others who are far removed from being orators.
And yet Apollodorus is not very far off this definition when he asserts that the first and all-important task of forensic oratory is to persuade the judge and lead his mind to the conclusions desired by the speaker. For