Ammonius was a student of Proclus in Athens and was the head of the Neoplatonic Academy in Alexandria where he taught all of the major Neoplatonists of the 6th century. His work on ‹Peri hermeneias‹ was part of his explanation of Aristotelian logic (cf. CAGL 9) and was based on Proclus‹ interpretation of this work, supplemented by the commentaries of Porphyrius and Syrianus. Ammonius' commentary provides an explanation of the various meanings of »truth» and contains an important essay on determinism which explores numerous key Greek ideas. Ammonius' work on ‹Peri hermeneias‹ influenced the Arabic and the Latin-speaking Middle Ages due to a translation by William Moerbeke. This volume provides the textual basis for studying the impact on the Latin Renaissance.