Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
Some have added a sixth department, subjoining judgment to invention, on the ground that it is necessary first to invented and then to exercise our judgment. For my own part I do not believe that invention can exist apart from judgement, since we do not say that a speaker has invented incousistent, two-edged or foolish arguments, but merely that he has failed to avoid them. It is true that Cicero in his Rhetorica [*]( No such statement is found in the de Inventione. )
includes judgment under mention; but in my opinion judgment is so inextricably mingled with the first three departments of rhetoric (for without judgment neither expression nor arrangement are possible), that I think that even delivery owes much to it. I say this with all the greater confidence because Cicero in
Others, who seem to me to have been no less desirous than those mentioned above to introduce some novelty, have added order, although they had already mentioned arrangement, as though arrangement was anything else than the marshalling of arguments in the best possible order. Dion taught that oratory consisted only of invention and arrangement, but added that each of these departments was twofold in nature, being concerned with words and things, so that expression comes under invention, and delivery under arrangement, while memory must be added as a fifth department. The followers of Theodorus divide invention into two parts, the one concerned with matter and the other with expression, and then add the three remaining departments.
Hermagoras places judgment, division, order and everything relating to expression under the heading of economy, a Greek word meaning the management of domestic affairs which is applied metaphorically to oratory and has no Latin equivalent.