Aëtius, Achilles, Epicurus and Lucretius on the Phases and Eclipses of the Moon

Abstract

Abstract Although chapter 2.29 of Aëtius’ Placita claims to be dealing with lunar eclipses, several of its lemmas are actually concerned with the moon’s ‘monthly concealment’, i.e. new moon. This paper will show that, save for one obvious transposition, all lemmas in the first part of the chapter are in fact concerned with the new moon, while only those at the end deal with lunar eclipses. This is best explained on the assumption that in Aëtius 2.29 two separate chapters have been conflated, the first dealing with the phases of the moon, and the other with lunar eclipses. It is further shown that while the first portion is virtually complete, the second is not, preserving only lemmas which presuppose that the moon reflects the light of the sun. A doxographical passage in Ach. Isag. 21, where new moon and the lunar eclipse are similarly confused, suggests that the conflation must have been already present in its and Aëtius’ common Vorlage. On the other hand, Epicurus and Lucretius, believed to have culled their astronomical theories from doxographical works, clearly distinguish the two phenomena and provide useful clues as to the lemmas missing from Aëtius 2.29.