Institutio Oratoria

These problems, however, may be left to those who hold that rhetoric is the power to persuade. If our definition of rhetoric as the science of speaking well implies that an orator must be a good man, there can be no doubt about its usefulness.

And in truth that god, who was in the beginning, the father of all things and the architect of the universe, distinguished man from all other living creatures that are subject to death, by nothing more than this, that he gave him the gift of speech.

For as regards physical bulk, strength, robustness, endurance or speed, man is surpassed in certain cases by dumb beasts, who also are far more independent of external assistance. They know by instinct without need of any teacher how to move rapidly, to feed themselves and swim.