Institutio Oratoria

How wide, almost universal, was the knowledge that Varro communicated to the world! What of all that goes to make up the equipment of an orator was lacking to Cicero? Why should I say

more, since even Cornelius Celsus, a man of very ordinary ability, not merely wrote about rhetoric in all its departments, but left treatises on the art of war, agriculture and medicine as well. Indeed the high ambition revealed by his design gives him the right to ask us to believe that he was acquainted with all these subjects.