Institutio Oratoria

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?