Institutio Oratoria

Again Gorgias, [*](Gorg. 453 A. ) in the dialogue of Plato that takes its title from his name, says practically the same thing, but Plato intends it to be taken as the opinion of Gorgias, not as his own. Cicero [*](de Inv. I. v. 6, de Or. I. xxxi. 138 ) in more than one passage defined the duty of an orator as

speaking in a persuasive manner.

In his Rhelorica [*](cp. III. i. 20 and Cic. de Or. I. ii. 5. The work in question is better known as the de Inventione. ) too, a work which it is clear gave him no satisfaction, he makes the end to be persuasion. But many other things have the power of persuasion, such as money, influence, the authority and rank of the speaker, or even some sight unsupported by language, when for instance the place of words is supplied by the memory of some individual's great deeds, by his lamentable appearance or the beauty of his person.

Thus when Antonius in the course of his defence of Manius Aquilius tore open his client's robe and revealed the honourable scars which he had acquired while facing his country's foes, he relied no longer on the power of his eloquence, but appealed directly to the eyes of the Roman people. And it is believed that they were so profoundly moved by the sight as to acquit the accused.