For original authorities in reference to the matter of this chapter, read Diogenes Laertius's Lives of the Philosophers; the Writings of Plato and Aristotle; Cicero, De Natura Deorum, De Oratore, De Officiis, De Divinatione, De Finibus, Tusculanae Disputationes; Xenophon, Memorabilia; Boethius, De Consolatione Philosophiae; Lucretius.

Academica, an exposition of the New Academic Philosophy, advocating probability rather than certainty as the foundation of philosophy; De Finibus Bonorum et Malorum, a work criticising the most prominent views entertained concerning Ethics; Disputationes Tusculanae, treating of certain conditions essential to morality and happiness;

For example, he enlisted the aid of Cristoforo Landino, who in his Disputationes Camaldunenses had really inaugurated the science of textual criticism by urging that a careful comparison of the various codices should constitute the preliminary step in any reproduction of the classics. Landino's work on Vergil and Horace merits the warmest praise.

We see this in the Topica, the De Finibus, and the Tusculanae Disputationes, in all of which he was greatly assisted by the Academic point of view which strove to reconcile philosophy with the dictates of common sense.

In order to train candidates in this art, university and college teachers gave frequent exhibitions of disputations, which from being on any subject, de quolibet, were styled 'quodlibeticae questiones', or 'disputationes'. A high dignitary presided, with the title of 'dominus quodlibetarius', and propounded questions, usually one supported by arguments and two plain; and then the disputer, who presumably came prepared, delivered his reply, clear cut into fine distinctions and bristling with citations from recognized authorities.