 Al-Fārābī’s influence is particularly obvious in the enumeration of the seven parts of grammar, the eight parts of natural science (covering the spectrum of Aristotle’s libri naturales), and the seven parts of mathematics: arithmetic, music, geometry, optics, astrology, astronomy, the science of weights, the science of technical devices (ingenia) (see the tables in Bouyges 1923, 65–69). As to the discipline of logic, Gundisalvi explicitly embraces al-Fārābī’s division into eight parts, following the tradition which makes Aristotle’s Rhetoric and Poetic parts of logic. The Farabian division of logic into eight parts reappears, for example, in Roger Bacon (Maierù 1987) and in Arnoul de Provence’s Division of the Sciences (ca. 1250); Arnoul remarks that neither Aristotle nor common usage includes Rhetoric and Poetic among the parts of logic (Lafleur 1988, 342). Gundisalvi further distinguishes with al-Fārābī between five kinds of syllogistic reasoning, of which demonstration is the highest. Al-Fārābī’s emphasis on demonstration as the pivotal means for the acquisition of certain knowledge is an important innovation of Arabic philosophy, which reached the Latin West via Gundisalvi (Fidora 2007).