Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
And yet there are some who take pleasure in directing their onslaughts against their opponents' counsel as well, a practice which, unless they have deserved such attacks, shows an inhuman disregard of the duties incumbent on the profession, and is not merely useless to the speaker (since he thereby gives his opponent the right to reply in the same strain), but contrary to the interests of his case, since it creates a hosthe and antagonistic disposition in the advocates attacked, whose eloquence, however feeble it may be, will be redoubled by resentment at the insults to which they have been subjected.
Above all, it involves a complete waste of one of the most valuable of an orator's assets, namely that self-restraint which gives weight and credit to his words, if he debases himself from an honest man into a snarling wrangler, directing all his efforts not to win the goodwill of the judge, but to gratify his client's spite.
Often too the attractions of freedom of speech will lure him into a rashness of language perilous not merely to the interests of the case, but to those of the speaker
In view of the tact that there is commonly a great variety in the aims which pleaders set before themselves and that the diligence shown by some is branded as tedious caution, while the readiness of others is criticised as rashness, I think that this will be an appropriate place to set forth my views as to how the orator may strike the happy mean.