 Much of this section is devoted to logic, the “instrument” of sciences according to Aristotle and a view widely shared by Muslims (see Epistles 10–14). These treatises take the place of grammar, logic and rhetoric, that in Middle Ages constituted the “trivium” (in Latin: “the three ways”) sciences and were the basis of a “liberal arts” education. There is no place for poetry or for rhetorical devices in the encyclopedia. Dialectics increases damaging opposition among the learned. Although the Ikhwân appear interested in spoken language and even in phonetics, they never approach grammar as a science. Rather, they examine the technique of the “universal” form of language – logic. In the well-known 10th century debate on the superiority of grammar or of logic, they might have sided with the Christian logician Abû Bishr Mattâ ibn Yûnus more than with the grammarian Abû Sa‘îd al-Sirafî (cf. Heck 2008, 11 for a new perspective on this issue). “Trivium” was considered preparatory for the “quadrivium,” which was in turn considered preparatory for the study of philosophy and theology. The “trivium” and “quadrivium” sciences are described in the encyclopedia in an original way as distinct from that of other Muslim writers as well as the Latin west (de Callataÿ 2005, 61–62). Hellenistic influence is remarkable even when the Ikhwân rely on Aristotelian logic. The logical treatises include paraphrases of Porphiry's Isagoges, which the later Greeks considered to be the first book of Organon (Rhetoric and Poetics were taken to be its last books). It is followed by Aristotle's Categories, De interpretatione, Prior and Posterior Analytics.