Quintilian Institutio Oratoria 12.10.1

[1] The question of the to be adopted remains to be discussed. This was described in my original division ¹ of my subject as forming its third portion: for I promised that I would speak of the art, the artist and the work. But since oratory is the work both of rhetoric and of the orator, and since it has many forms, as I shall show, the art and the artist are involved in the consideration of all these forms. But they differ greatly from one another, and not merely in species, as statue differs from statue, picture from picture and speech from speech, but in genus as well, as, for example, Etruscan statues differ from Greek and Asiatic orators from Attic.