John Cotton Dana's remarks on a quotation suitable for inscription on a new building at Newark State College, Union, New Jersey (1912) as quoted in "The New York Times Book Review" (p. 55.), March 5, 1967.
Marcus Tullius Cicero (1853). “The Academic Questions, Treatise de Finibus, and Tusculan Disputations, of Marcus Tullius Cicero: With a Sketch of the Greek Philosophers Mentioned by Cicero”, p.114