Institutio Oratoria

Quintilian

Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.

The conflict is

v1-3 p.341
between case and case, not between rhetoric and itself. And even if persons who have learned the same thing fight one another, that does not prove that what they have learned is not an art. Were that so, there could be no art of arms, since gladiators trained under the same master are often matched against each other;

nor would the pilot's art exist, because in sea-fights pilots may be found on different sides; nor yet could there be an art of generalship, since general is pitted against general. In the same way rhetoric does not undo its own work. For the orator does not refute his own arguments, nor does rhetoric even do so, because those who regard persuasion as its end, or the two good men whom chance has matched against one another seek merely for probabilities: and the fact that one thing is more credible than another, does not involve contradiction between the two.