Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
Moreover Demosthenes
His speech would have been much less effective, if any other figure had been used, as will be all the more clearly realised, if the whole of that most vigorous passage
You are, then, in possession, Tubero, of the most valuable advantage that can fall to an accuser etc.be altered so as to be addressed to the judge. For it is a real and most unnatural diversion of the passage, which destroys its whole force, if we say
Tubero is then in possession of the most valuable advantage that can fall to an accuser.
In the original form Cicero attacks his opponent and presses him hard, in the passage as altered he would merely have pointed out a fact. The same thing results if you alter the turn of the passage in Demosthenes. Again did not Sallust when speaking against Cicero himself address his exordium to him and not to the judge? In fact he actually opens with the words
I should feel deeply injured by your reflexions on my character, Marcus Tullius,wherein he followed the precedent set by Cicero in his speech against Catiline where he opens with the words
How long will you continue to abuse our patience?
Finally to remove all reason for feeling surprise at the employment of apostrophe, Cicero in his defence of Scaurus, [*]( This speech is lost: the existing speech in his defence is on the charge of extortion. ) on a charge of bribery (the speech is to be found in his Notebooks; for he defended him twice) actually introduces an imaginary person speaking on behalf of the accused, while in his pro Rahirio and his speech in defence of this same Scaurus on a charge of extortion he
Still such artifices, although they may be employed at times to good effect, are not to be indulged in indiscriminately, but only when there is strong reason for breaking the rule. The same remark applies to simile (which must however be brief), metaphor and other tropes, all of which are forbidden by our cautious and pedantic teachers of rhetoric, but which we shall none the less occasionally employ, unless indeed we are to disapprove of the magnificent example of irony in the pro Ligario to which I have already referred a few pages back.