In concluding his authoritative study, A History of Literary Criticism in the Renaissance, Spingarn asserts that before the sixteenth century, "Poetic theory had been nourished upon the rhetorical and oratorical treatises of Cicero, the moral treatises of Plutarch (especially those upon the reading of poets and the education of youth), the Institutions Oratoriae of Quintilian, and the De Legendis Gentilium Libris of Basil the Great."