Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
But, while others besides
v1-3 p.309
orators may discover what is credible as well as persuasive, by adding the words in every subject he, to a greater extent than the others, concedes the fairest name in all the world to those who use their gifts as an incitement to crime . Plato makes Gorgias [*](Gorg. 454 B. ) say that he is a master of persuasion in the law-courts and other assemblies, and that his themes are justice and injustice, while in reply Socrates allows him the power of persuading, but not of teaching.
Those who refused to make the sphere of oratory allinclusive, have been obliged to make somewhat forced and long-winded distinctions: among these I may mention Ariston, the pupil of the Peripatetic Critolaus, who produced the following definition,
Rhetoric is the science of seeing and uttering what ought to be said on political questions in language that is likely to prove persuasive to the people.