 The sources on which Ammonius drew and his mode of using them will likely have varied according to the nature of the previous commentaries he could work with for each text. In Asclepius’ published version of Ammonius’ lectures, for example, we see a very different procedure from the one Ammonius followed in writing out his own commentary on De Interpretatione and basing it on Proclus’ lectures. It is difficult to say to what extent Asclepius’ commentary on Metaphysics A–Z is either a reflection or a more thorough reworking of Ammonius’ lectures. Still, this work is reasonably thought to give the best representation we have of the lectures themselves, copied down by Ammonius’ student ‘from the voice’ of the master. Indications of the commentary’s origin in the lectures abound (cf. Luna 2001, 100–103): the explanation of a passage often begins by referring to “what was said yesterday” (e.g., 3,13; 433,18–19); we are told that “the teacher of medicine Asclepius, who studied with us at these lessons” raised a question, and “our professor of philosophy” answered him (143,31 ff.). That faithful transcription of lectures was practiced and thus could have formed the basis of a later reworking for publication is implied by Damascius’ story (45A) about Theosebius, who compared his own transcripts of lectures on the Gorgias given at two different times by his master Hierocles and found nothing repeated between the two versions, “each of which, however improbable it is to hear, hewed as much as possible to the intention of Plato”. 