Reference point: p. 15. Quoted in Cicero, Tusculum Disputations, 3.29. The Euripidean source isn’t known. Id., p. 98, suggests Pirithous and notes that a line of the quote is attested in Euripides fr. 964 Nauck.
author: Graver, Margaret and Cicero, Marcus Tullius
title: Cicero on the emotions : Tusculan disputations 3 and 4
publisher: University of Chicago Press