Cicero, Oratore II 14 (Cicero is not the speaker here…)
“What, then? There is something else still, I will admit, that, as when I walk in the sun—even if I am doing so for some other reason—I still grow darker by nature. Something similar happens when I eagerly read those books at Misenum—for Rome scarcely allows it. I sense that my own speaking takes own a new appearance from this contact. But, so that this does not seem too general to you, I understand only those things contained within Greek works which their very authors conceded the common people to understand.
When by chance I come upon your philosophers, led astray by the titles of their books which are titled with common and famous names—on virtue, justice, goodness, pleasure—I do not understand any word: they are so bound up in precise and abbreviated argumentation. I don’t even try to manage the Greek poets at all since they are communicated in an entirely different language. No, I lose myself, as I have said, with those who write histories or present speeches which they wrote, or who speak in a what that they don’t seem to wish that we be the most well educated men, but merely conversant.”
Quid ergo? Est, fatebor, aliquid tamen: ut, cum in sole ambulem, etiamsi aliam ob causam ambulem, fieri natura tamen, ut colorer: sic, cum istos libros ad Misenum (nam Romae vix licet) studiosius legerim, sentio illorum tactu orationem meam quasi colorari. Sed ne latius hoc vobis patere videatur, haec duntaxat in Graecis intellego, quae ipsi, qui scripserunt, voluerunt vulgo intellegi. In philosophos vestros si quando incidi, deceptus indicibus librorum, quod sunt fere inscripti de rebus notis et illustribus, de virtute, de iustitia, de honestate, de voluptate, verbum prorsus nullum intellego: ita sunt angustis et concisis disputationibus illigati. Poetas omnino, quasi alia quadam lingua locutos, non conor attingere: cum his me (ut dixi) oblecto, qui res gestas, aut qui orationes scripserunt suas, aut qui ita loquuntur, ut videantur voluisse nobis, qui non sumus eruditissimi, esse familiars…