Simplicius of Cilicia (in Asia Minor) tells us that he studied Platonic philosophy in Alexandria under Ammonius the son of Hermias (fl. c. 550). Afterward, he attended the lectures of Damascius, probably in Athens at the original and still flourishing school founded by Plato himself, the Academy. (An earlier scholarly opinion that there were doctrinal differences between the teachings on Plato in Alexandria and Athens is no longer held.)

All these figures were active neoplatonists, and Hermias and Damascius did in fact publish commentaries on various dialogues of Plato. But Ammonius and Simplicius (and to a lesser extent Damascius as well) devoted most of their writings to the explication of Aristotle's works. Simplicius, in addition to a commentary on Epictetus's Handbook (Enchiridion), wrote extensive commentaries on five of those works of Aristotle that most challenge philosophers: Metaphysics (no longer extant, although fragments are known), Physics...