Shams al-Din al-Samarqandi on Quantity of Hypothetical Syllogism

Shams al-Din al-Samarqandi, who has proposed a modern point of view in opposition of Avicenna on hypothetical syllogism, claimed that 12 of 19 moods of Avicennan valid hypothetical syllogism is indeed invalid. in another paper, I showed that if we consider only quality of propositions there emerges a surprising correspondence between his valid syllogisms and those of relevance logic. In this paper, however, I’ll show that if we consider quantity of propositions too, this correspondence disappears. This is because discussing particular conditionals, Samarqandi held, as Avicenna did, that particular implicational conditionals can be analyzed as distinct both from universal implicational and from particular contingent (or accidental) conditionals. No analyses of particular implicational conditionals so far proposed could escape this objection.Relevance logic, Hypothetical syllogism, Shams al-Din al-Samarqandi, quantity