Quintilian, Institutio Oratoria, Book 10
Harold Edgeworth Butler, Ed.

[44] And even if we turn to those who desire to follow the correct methods of style, we shall find that some think that the only healthy and genuinely Attic style is to be found in language which is restrained and simple and as little removed as possible from the speech of every day, while others are attracted by a style which is more elevated and full of energy and animation. There are, too, not a few who are devoted to a gentle, elegant and harmonious style. Of these different ideals I shall speak in greater detail, when I come to discuss the question of the particular styles best suited to oratory.¹ For the moment I shall restrict myself to touching briefly on what the student who desires to consolidate his powers of speaking should seek in his reading and to what kind of reading he should devote his attention. My design is merely to select a few of the most eminent authors for consideration.