Institutio Oratoria

There is no point in the whole speech where confusion of memory or loss of fluency has a worse effect,

The length of the exordium will be determined by the case; simple cases require a short introduction only, longer exordia being best suited to cases which are complicated, suspect or unpopular. As for those who have laid it down as a law applying to all exordia that they should not be more than four sentences long, they are merely absurd. On the other hand undue length is equally to be avoided, lest the head should seem to have grown out of all proportion to the body and the judge should be wearied by that which ought to prepare him for what is to follow.

The figure which the Greeks call apostrophe, by which is meant the diversion of our words to address some person other than the judge, is entirely banned by some rhetoricians as far as the exordium is concerned, and for this they have some reason, since it would certainly seem to be more natural that we should specially address ourselves to those whose favour we desire to win.

Occasionally however some striking expression of thought is necessary in the exordium which can be given greater point and vehemence if addressed to some person other than the judge. In such a case what law or what preposterous superstition is to prevent us from adding force to such expression of our thought by the use of this figure?

For the writers of text-books do not forbid it because they regard it as illicit, but because they think it useless. Consequently if its utility be proved, we shall have to employ it for the very reason for which we are now forbidden to do so.