Until the launch of this series over fifteen years ago, the 15,000 volumes of the ancient Greek commentators on Aristotle, written mainly between 200 and 600 AD, constituted the largest corpus of extant Greek philosophical writings not translated into English or other European languages. In this, the first half of Philoponus' analysis of book one of Aristotle's Physics, the principal themes are metaphysical. Aristotle's opening chapter in the Physics is an abstract reflection on methodology for the investigation of nature, or 'physics'. Aristotle suggests that one must proceed from things that are familiar but vague, and derive more precise but less obvious principles to constitute genuine knowledge. His controversial claim that this is to progress from the universal to the more particular occasions extensive apologetic exegesis, typical of Philoponus' meticulous and somewhat pedantic method. Philoponus explains away the apparent conflict between the 'didactic method' (unavoidable in physics) and the strict demonstrative method described in the Analytics. After 20 pages on Chapter 1, Philoponus devotes the remaining 66 pages to Aristotle's objections to two major Presocratic thinkers, Parmenides and Melissus. Aristotle included these thinkers as an aside, because they were not engaged in physics, but in questioning the very basis of physics. Philoponus investigates Aristotle's claims about the relation between a science and its axioms, explores alternative ways of formalising Aristotle's refutation of Eleatic monism and provides a sustained critique of Aristotle's analysis of the Eleatics' purported mistakes about unity and being.

Themistius' treatment of Books 1-3 of Aristotle's Physics presents central features of Aristotle's thought about principles, causation, change and infinity. The tradition of synthesising and epitomising exegesis is here raised to a new level by the innovative method of paraphrase pioneered by Themistius. Taking a selective, but telling, account of the earlier Peripatetic and Presocratic tradition, Themistius creates a framework that can still be profitably used in the study of Aristotle. This volume contains the first English translation of Themistius' commentary, accompanied by a detailed introduction, extensive explanatory notes and a bibliography.

Aristotle's Physics Book 3 covers two subjects: the definition of change and the finitude of the universe. Change enters into the very definition of nature as an internal source of change. Change receives two definitions in chapters 1 and 2, as involving the actualisation of the potential or of the changeable. Alexander of Aphrodisias is reported as thinking that the second version is designed to show that Book 3, like Book 5, means to disqualify change in relations from being genuine change. Aristotle's successor Theophrastus, we are told, and Simplicius himself, prefer to admit relational change. Chapter 3 introduces a general causal principle that the activity of the agent causing change is in the patient undergoing change, and that the causing and undergoing are to be counted as only one activity, however different in definition. Simplicius points out that this paves the way for Aristotle's God who moves the heavens, while admitting no motion in himself. It is also the basis of Aristotle's doctrine, central to Neoplatonism, that intellect is one with the objects it contemplates.In defending Aristotle's claim that the universe is spatially finite, Simplicius has to meet Archytas' question, "What happens at the edge?". He replies that, given Aristotle's definition of place, there is nothing, rather than an empty place, beyond the furthest stars, and one cannot stretch one's hand into nothing, nor be prevented by nothing. But why is Aristotle's beginningless universe not temporally infinite? Simplicius answers that the past years no longer exist, so one never has an infinite collection.

In this, the first half of Philoponus' analysis of book one of "Aristotle's Physics", the principal themes are metaphysical. Aristotle's opening chapter in the "Physics" is an abstract reflection on methodology for the investigation of nature, 'physics'. Aristotle suggests that one must proceed from things that are familiar but vague, and derive more precise but less obvious principles to constitute genuine knowledge. His controversial claim that this is to progress from the universal to the more particular occasions extensive apologetic exegesis, typical of Philoponus' meticulous and somewhat pedantic method. Philoponus explains away the apparent conflict between the 'didactic method' (unavoidable in physics) and the strict demonstrative method described in the "Analytics". After 20 pages on chapter 1, Philoponus devotes the remaining 66 pages to Aristotle's objections to two major Presocratic thinkers, Parmenides and Melissus. Aristotle included these thinkers as an aside, because they were not engaged in physics, but in questioning the very basis of physics. Philoponus investigates Aristotle's claims about the relation between a science and its axioms, explores alternative ways of formalising Aristotle's refutation of Eleatic monism and provides a sustained critique of Aristotle's analysis of the Eleatics' purported mistakes about unity and being.

Aristotle's Physics 1.4-9 explores a range of questions about the basic structure of reality, the nature of prime matter, the principles of change, the relation between form and matter, and the issue of whether things can come into being out of nothing, and if so, in what sense that is true. Philoponus' commentaries do not merely report and explain Aristotle and the other thinkers whom Aristotle is discussing. They are also the philosophical work of an independent thinker in the Neoplatonic tradition. Philoponus has his own, occasionally idiosyncratic, views on a number of important issues, and he sometimes disagrees with other teachers whose views he has encountered perhaps in written texts and in oral delivery. A number of distinctive passages of philosophical importance occur in this part of Book 1, in which we see Philoponus at work on issues in physics and cosmology, as well as logic and metaphysics. This volume contains an English translation of Philoponus' commentary, as well as a detailed introduction, commentary notes and a bibliography.