Nicene and Post-Nicene Fathers, Vol. II:
On Christian Doctrine: Chapter 17

p. 586

Chapter 17.—Threefold Division of The Various Styles of Speech.

34.  He then who, in speaking, aims at enforcing what is good, should not despise any of those three objects, either to teach, or to give pleasure, or to move, and should pray and strive, as we have said above, to be heard with intelligence, with pleasure, and with ready compliance.  And when he does this with elegance and propriety, he may justly be called eloquent, even though he do not carry with him the assent of his hearer.  For it is these three ends, viz., teaching, giving pleasure, and moving, that the great master of Roman eloquence himself seems to have intended that the following three directions should subserve:  “He, then, shall be eloquent, who can say little things in a subdued style, moderate things in a temperate style, and great things in a majestic style:” 1971   as if he had taken in also the three ends mentioned above, and had embraced the whole in one sentence thus:  “He, then, shall be eloquent, who can say little things in a subdued style, in order to give instruction, moderate things in a temperate style, in order to give pleasure, and great things in a majestic style, in order to sway the mind.”

Footnotes

Cicero, Orator. 29:  “Is igitur erit eloquens, qui poterit parva summisse, modica temperate, magna granditer dicere.”