The eighth book of Aristotle's Physics is the culmination of his theory of nature. He discusses not just physics, but the origins of the universe and the metaphysical foundations of cosmology and physical science. He moves from the discussion of motion in the cosmos to the identification of a single source and regulating principle of all motion, and so argues for the existence of a first 'unmoved mover'. Daniel Graham offers a clear, accurate new translation of this key text in the history of Western thought, and accompanies the translation with a careful philosophical commentary to guide the reader towards an understanding of the wealth of important and influential arguments and ideas that Aristotle puts forward.
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.
Book 3 of Aristotle's Physics primarily concerns two important concepts for his theory of nature: change and infinity. Change is important because, in Book 2, he has defined nature - the subject-matter of the Physics - as an internal source of change. Much of his discussion is dedicated to showing that the change occurs in the patient which undergoes it, not in the agent which causes it. Thus Book 3 is an important step in clearing the way for Book 8's claims for a divine mover who causes change but in whom no change occurs. The second half of Book 3 introduces Aristotle's doctrine of infinity as something which is always potential, never actual, never traversed and never multiplied. Here, as elsewhere, Philoponus the Christian turns Aristotle's own infinity arguments against the pagan Neoplatonist belief in a beginningless universe. Such a universe, Philoponus replies, would involve actual infinity of past years already traversed, and a multiple number of past days. The commentary also contains intimations of the doctrine of impetus - which has been regarded, in its medieval context, as a scientific revolution - as well as striking examples of Philoponus' use of thought experiments to establish philosophical and broadly scientific conclusions.
Aristotle's Physics is one of the least studied "great books"--physics has come to mean something entirely different than Aristotle's inquiry into nature, and stereotyped Medieval interpretations have buried the original text. Sach's translation is really the only one that I know of that attempts to take the reader back to the text itself. -- Leon Cass, University of Chicago
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.
Martin Heidegger's reading of Aristotle was one of the pivotal influences in the development of his philosophy. First published in German in 1981 as volume 33 of Heidegger's Collected Works, this book translates a lecture course he presented at the University of Freiburg in 1931. Heidegger's careful translation and his probing commentary on the first three chapters of Book IX of Metaphysics show the close correlation between his phenomenological interpretation of the Greeks (especially of Aristotle) and his critique of metaphysics. Additionally, Heidegger's confrontation with Aristotle's Greek text makes a significant contribution to contemporary scholarship on Aristotle, particularly the understanding of potentiality in Aristotle's thought. Finally, the book exemplifies Heidegger's gift for teaching students how to read a philosophical text and how to question that text in a philosophical way.
Book 2 of the Physics is arguably the best introduction to Aristotle's work, both because it explains some of his central concepts, such as nature and the four causes, and because it asks some gripping questions that are still debated today: Is chance something real? If so, what? Can nature be explained by chance, necessity and natural selection, or is it purposive? Philoponus' commentary is not only a valuable guide, but also a work of Neoplatonism with its own views on causation, the Providence of Nature, the problem of evil and the immortality of the soul.
