Reference edition:

Categoriarum supplementa. Pophyrii Isagoge translatio Boethii et Anonymi fragmentum uulgo uocatum 'Liber sex principiorum' Accedunt Isagoges fragmenta M. Victorino interprete et specimina translationum recentiorum categoriarum, edidit Laurentius Minio-Paluello, aduiuante Bernardo G. Dod, Bruges Paris 1966 (ristampa 1995).

Counted among Boethius’ first works are two commentaries on Porphyry’s Isagoge; he wrote these in the wake of Victorinus’s earlier commentary, which he derided as a “translation rich in eloquence, but philosophically sterile” (Crocco 1975).  The first text, like that of Porphyry, is divided into two books, albeit with a different structure: one covers prolegomena and the other treats questions of universals, genus, species, differentia, proprium, and accidens.  The second text covers the same material in five books.

The commentaries are written as a dialogue with an interlocutor called Fabius who is probably made up.

The two works were written perhaps five years apart.  The first is directed at a less experienced reader, while the second is intended for a more specialized audience.  Although his framework is based on Aristotelian theory, Boethius’s language reflects Platonic categories.

The manuscripts transmit various titles for the two commentaries, both of which come down to us in diverse forms.  Some codices contain only the first, others only the second; some contain both, while others transmit the Isagoge without a commentary, etc.  The first print edition was made at Venice in 1492, but Keller published the Isagoge by itself at Augsburg in 1479. [M. Manca; tr. C. L. Caterine].