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 intermediate style will have more frequent recourse to metaphor and will make a more attractive use of figures, while it will introduce alluring digressions, will be neat in rhythm and pleasing in its reflexions: its flow, however, will be gentle, like that of a river whose waters are clear, but overshadowed by the green banks on either side.
But he whose eloquence is like to some great torrent that rolls down rocks and
disdains a bridge[*]( Verg. Aen. viii. 728. ) and carves out its own banks for itself, will sweep the judge from his feet, struggle as he may, and force him to go whither he bears him. This is the orator that will call the dead to life (as, for example, Cicero calls upon Appius Caecus [*]( See III. viii. 54. Cicero in the pro Caclio makes both Appius Caecus and her brother Clodius address Clodia the former rebuking her for her immorality, the latter exhorting her thereto. ) ); it is in his pages that his native land itself will cry aloud and at times address the orator himself, as it addresses Cicero in the speech delivered against Catiline in the senate.