Note 16 — Chapter VI · RHETORIC AND LOGIC IN THE TWELFTH AND THIRTEENTH CENTURIES

See the preceding section. John mentions Hugh at 833 A, 924 B. The word disserere Hugh and John may have taken, as John took other things at the opening of Book II, from Isidore (see above, page 97); but the ultimate source of the phrase ratio disserendi is probably Cicero’s Topica: “omnis ratio diligens disserendi duas habet partes, unum inveniendi alteram iudicandi.” Top. 2. Cf. Fin. 1. 7. 22; Fat. 1. 1. Disserere seems limited to dialectica in De orat. I. 9 (see Wilkins’s note); but using the same word in II. 157, Cicero points out that the proper function of dialectica is analysis (iudicium, not inventio). In Orator 113, discussing the common ground of rhetoric and logic, he says “utrumque in disserendo est,” and goes on to distinguish logic as ratio disputandi from rhetoric as ratio dicendi. Dicere is generally his word for rhetoric. Quintilian, whom John uses largely, probably has in mind the same distinction in X. 1. 81, though in other places he uses disserere more generally.