The paper is in three parts, prefaced by general remarks concerning Boethius' logical translations and commentaries: the text of the Peri Hermeneias as known to and commented on by Boethius (and Ammonius); the organizational principles behind Boethius' second commentary on the Peri Hermeneias; its source(s). One of the main purposes of the last section is to demonstrate that the Peri Hermeneias commentaries of Boethius and Ammonius are, although part of a common tradition, quite independent of one another, and special consideration is given to the question of how Boethius interpreted and shaped the doxographical material concerning Aspasius, Herminus, and Alexander that had been handed down to him by Porphyry.