 We saw in  Section 3  above that al-Fārābī believed Aristotle had prescribed universal rules for demonstrative reasoning in his Posterior Analytics. But apart from some discussion of techniques for finding definitions, the only rules that al-Fārābī offers us in [Demonstration] are categorical syllogisms in mood Barbara with extra pieces clamped on. (These are in the section [Demonstration] 33.1–39.4; they are quoted in Hasnawi &amp; Hodges 2016.)