Institutio Oratoria

I am not ignorant of the generally prevailing custom, nor have I forgotten those who sit by our store-chests and provide weapons for the pleader: I know too that the Greeks did likewise: hence the name of pragmaticus which was bestowed on such persons. But I am speaking of an orator, who owes it as a duty to his case to serve it not merely by the loudness of his voice, but by all other means that may be of assistance to it.