On Aristotle's "On the Heavens 1.10–12"In the three chapters of "On the Heavens" dealt with in this volume, Aristotle argues that the universe is ungenerated and indestructible. In Simplicius' commentary, translated here, we see a battle royal between the Neoplatonist Simplicius and the Aristotelian, Alexander, whose lost commentary on "On the Heavens" Simplicius partly preserves. Simplicius' rival, the Christian Philoponus, had conducted a parallel battle in his "Against Proclus" but had