Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
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.