Gargantua and Pantagruel on De Divinatione: “as Plato, in Critone, Cicero, in Primo, de Divinatione, Diogenes Laertius, and others, have to the full recorded in their works.”
The City of God on De Republica: “The opinion of the ancient Romans on this matter is attested by Cicero in his work _De Republica_, in which Scipio, one of the interlocutors, says, "The lewdness of comedy could never have been suffered by audiences, unless the customs of society had previously sanctioned the same lewdness."”
Gargantua and Pantagruel on De Senectute: “in verification whereof thou hast the authority of Marcus Tullius in his book of old age, and the sentence of Plutarch in the book entitled How a man may praise himself without envy”
The Souls of Black Folk on Pro Archia Poeta: “I put Cicero “pro Archia Poeta” into the simplest English with local applications, and usually convinced them”
Gargantua and Pantagruel on De Finibus Bonorum et Malorum: “This detestable saying, of which Cicero, lib. De Finib., and Seneca, lib. 2, De Clementia, make mention, is ascribed to the Emperor Tiberius by Dion Nicaeus and Suidas.”