Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
But in my young days advocates grown old in pleading used to lay it down as a rule that we should never be in a hurry to propose that our opponent should take an oath, just as we should never allow him the choice of a judge [*]( The choice of the single iudex in civil cases rested with the plaintiff, though the defendant had the right to refuse the person proposed. ) nor select our judge from among the supporters of the opposite side: for if it is regarded as a disgrace to such a supporter [*]( Not an actual advocate, but a supporter and adviser on points of law. ) to say anything against his client, it is surely a still worse disgrace that he should do anything that will harm his client's case.