Abstract: Discusses Boethius's logical monographs: his treatises on division, on categorical syllogisms, and most importantly, his works on the theory of topical argument and on hypothetical syllogisms. The theory of topics, as developed in late antiquity and known almost entirely through Boethius, concerns the devising of arguments that rest on obvious general principles but are not, in their basic formulation, formally valid deductions. In his work on hypothetical syllogisms, Boethius seems to take account of Stoic propositional logic, but in fact, he does not properly grasp its principles. This chapter shows how Boethius's logical mongraphs fit with the Aristotelianizing approach of his commentaries.

Keywords: categorical syllogisms, hypothetical syllogisms, propositional logic, Stoic logic, topical argument,