let his manner of living be an eloquent sermon in itself

For men of quick intellect and glowing temperament find it easier to become eloquent by reading and listening to eloquent speakers than by following rules for eloquence.

would exercise the pupils under his care in the reading of history and even still more in that of speeches,

Examples are either (a) historical parallels, or (b) invented parallels, viz. either (a) illustrations or (b) fables, such as those of Aesop.

Every one who effects persuasion through proof does in fact use either enthymemes or examples: there is no other way.

The "example" has already been described as one kind of induction;