Abstract

The aim of this paper is to offer an alternative explanation to the notorious similitude detected in two ancient treatises on logic, namely, the Liber Peri Hermeneias, attributed to Apuleius of Madaura, and De syllogismo categorico, written by Boethius. Both were enormously authoritative in posterity. I argue that their similitude is due to the presence of an internal division of categorical propositions that Boethius gives in full in his De syllogismo categoricos, and repeats with extensions in his Introductio ad syllogismos categorico. The division outlines the three main parts of the theory: opposition, conversion and syllogism. This leads us to argue that similarity and correspondence of these two ancient logical treatises can be sufficiently explained from this resource, and insufficiently explained by a certain common literary source, which was proposed by Isaac, without clarifying some important dissimilarities and divergences contained in these treatises. Also, our hypothesis does not need to suppose, as Sullivan, that Boethius borrowed from Apuleius.