Ammonius' lecture expounded the most celebrated and discussed previous introduction written by Porphyry 200 years earlier, which was devoted to five main technical terms of Aristotle's logic. Ammonius was sympathetic to Porphyry because they both sought to harmonise the views of Plato and Aristotle with each other, arguing in different ways that the two philosophers did not disagree about the nature of universals. Porphyry's introduction was a hugely influential work for centuries after its composition, and this commentary by Ammonius served to maintain its position at the centre of later schools of philosophy.
This English translation of Ammonius' work is the latest volume in the Ancient Commentators on Aristotle series and makes this philosophical work accessible to a modern readership. The translation is accompanied by an introduction, comprehensive commentary notes, bibliography, glossary of translated terms and a subject index.