Simplicius' On Aristotle's "On the Soul 1.1-2.4" is a major source for late Neoplatonist theories of thought and sense perception and offers considerable insight into an important area of Aristotelian philosophy. The present volume is the only English translation of the commentary and affords its readers the opportunity to consider the question of its disputed authorship. While most scholars attribute authorship of On Aristotle's "On the Soul 1.1-2.4" to Simplicius, some have judged it to be the work of Priscian, or of another philosopher. The commentary discusses the first half of On the Soul, which comprises Aristotle's survey of his predecessors' views, as well as his own account of the nature of the soul.