Institutio Oratoria

By a trope is meant the artistic alteration of a word or phrase from its proper meaning to another. This is a subject which has given rise to interminable disputes among the teachers of literature, who have quarrelled no less violently with the philosophers than among themselves over the problem of the genera and species into which tropes may be divided, their number and their correct classification.

I propose to disregard such quibbles as in no wise concern the training of an orator, and to proceed to discuss those tropes which are most necessary and meet with most general acceptance, contenting myself merely with noting the fact that some tropes are employed to help out our meaning and others to adorn our style, that some arise from words used properly and others from words used metaphorically, and that the changes involved concern not merely individual words, but also our thoughts and the structure of our sentences.

In view of these facts I regard those writers as mistaken who have held that tropes necessarily involved the substitution of word for word. And I do not ignore the fact that