Paul Lettinck has restored a lost text of Philoponus by translating it for the first time from Arabic (only limited fragments have survived in the original Greek). The text, recovered from annotations in an Arabic translation of Aristotle, is an abridging paraphrase of Philoponus' commentary on Physics Books 5-7, with two final comments on Book 8. The Simplicius text, which consists of his comments on Aristotle's treatment of the void in chapters 6-9 of Book 4 of the Physics, comes from Simplicius' huge commentary on Book 4. Simplicius' comments on Aristotle's treatment of place and time have been translated by J. O. Urmson in two earlier volumes of this series.

The earlier part of the commentary by 'Philoponus' on Aristotle's On the Soul is translated by William Charlton in another volume in the series. This volume includes the latter part of the commentary along with a translation of Stephanus' commentary on Aristotle 's On Interpretation. It thus enables readers to assess for themselves Charlton's view that the commentary once ascribed to Philoponus should in fact be ascribed to Stephanus. The two treatises of Aristotle here commented on are very different from each other. In On Interpretation Aristotle studies the logic of opposed pairs of statements. It is in this context that Aristotle discusses the nature of language and the implications for determinism of opposed predictions about a future occurrence, such as a sea-battle. And Stephanus, like his predecessor Ammonius, brings in other deterministic arguments not considered by Aristotle ('The Reaper' and the argument from God's foreknowledge). In On the Soul 3.9-13, Aristotle introduces a theory of action and motivation and sums up the role of perception in animal life. Despite the differences in subject matter between the two texts, Charlton is able to make a good case for Stephanus' authorship of both commentaries. He also sees Stephanus as preserving what was valuable from Ammonius' earlier commentary On Interpretation, while bringing to bear the virtue of greater concision. At the same time, Stephanus reveals his Christian affiliations, in contrast to Ammonius, his pagan predecessor.

In On the Soul 3.1-8, Aristotle first discusses the functions common to all five senses, such as self-awareness, and then moves on to Imagination and Intellect. This commentary on Aristotle's text has traditionally been ascribed to Philoponus, but William Charlton argues here that it should be ascribed to a later commentator, Stephanus. (The quotation marks used around his name indicate this disputed authorship.) 'Philoponus' reports the postulation of a special faculty for self-awareness, intended to preserve the unity of the person. He disagrees with 'Simplicius', the author of another commentary on On the Soul (also available in this series), by insisting that Imagination can apprehend things as true or false, and he disagrees with Aristotle by saying that we are not always free to imagine them otherwise than as they are. On Aristotle's Active Intellect. 'Philoponus' surveys different interpretations, but ascribes to Plutarch of Athens, and rejects, the view adopted by the real Philoponus in his commentary on Aristotle's On Intellect that we have innate intellectual knowledge from a previous existence. Instead he takes the view that the Active Intellect enables us to form concepts by abstraction through serving as a model of something already separate from matter. Our commentator further disagrees with the real Philoponus by denying the Idealistic view that Platonic forms are intellects. Charlton sees 'Philoponus' as the excellent teacher and expositor that Stephanus was said to be.

These chapters of Aristotle's treatise are about physical interactions. In his innovative commentary, Philoponus discusses Aristotle's idea that certain qualities of the elements are basic. In what way are they basic? he asks. To what extent can the other qualities be reduced to the basic ones? And if the other qualities depend on the basic ones, how is it that they can vary independently of each other when the basic qualities change? Philoponus develops the idea that the other qualities merely supervene on the basic ones, rather than resulting from them. Moreover, physical qualities admit of different ranges of variation, and so have different thresholds at which they appear or disappear. Philoponus also discusses Aristotle's idea that the elements and their basic qualities survive potentially when mixed together. He explains this by drawing a third sense of 'potential' out of Aristotle's texts to take the place of the two senses which Aristotle explicitly recognises. Philoponus adds further restrictions to Aristotle's principles of causation. Black can contaminate white, but the black in ebony does not have the right matter for affecting the white of milk. He asks why fluids can affect each other more easily than solids. In every case, Philoponus takes Aristotle's discussions further, and his ideas on the dependence of some qualities on others are very relevant to the continuing philosophical debate on the subject.

The first five chapters of Aristotle's De Generatione et Corruptione distinguish creation and destruction from mere qualitative change and from growth. They include a fascinating debate about the atomists' analysis of creation and destruction as due to the rearrangement of indivisible atoms. Aristotle's rival belief in the infinite divisibility of matter is explained and defended against the atomists' powerful attack on infinite divisibility. But what inspired Philoponus most in his commentary is the topic of organic growth. How does it take place without ingested matter getting into the same place as the growing body? And how is personal identity preserved, if our matter is always in flux, and our form depends on our matter? If we do not depend on the persistence of matter why are we not immortal? Analogous problems of identity arise also for inanimate beings. Philoponus draws out a brief remark of Aristotle's to show that cause need not be like effect. For example, what makes something hard may be cold, not hard. This goes against a persistent philosophical prejudice, but Philoponus makes it plausible that Aristotle recognized this truth. These topics of identity over time and the principles of causation are still matters of intense discussion.

In 'On The Soul 2.1-6', Aristotle gives a very different account of the sould from Plato's by tying the soul to the body. The soul is the life-manifesting capacities that we all have and that distinguish living things, and explain their behaviour. He defines sould and life by reference to the capacities for using food to maintain structure and reproduce, for perceiving and desiring, and for rational thought. Capacities have to be defined by reference to the objects to which they are directed. The five senses, for example, are defined by reference to their objects, which are primarily forms like colour. And in perception we are said to receive these forms without matter.;Philoponus understands this reception not physiologically as the eye jelly's taking on colour patches, but 'cognitively', like Brentano, who much later thought that Aristotle was treating the forms as intentional objects. Philoponus is the patron of non-physiological interpretations, which are still a matter of controversy today.

This is one of the most interesting of all post-Aristotelian Greek philosophical texts, written at a crucial moment in the defeat of paganism by Christianity, AD 529, when the Emperor Justinian closed the pagan Neoplatonist school in Athens. Philoponus in Alexandria was a brilliant Christian philosopher, steeped in Neoplatonism, who turned the pagans' ideas against them. Here he attacks the most devout of the earlier Athenian pagan philosophers, Proclus, defending the distinctively Christian view that the universe had a beginning against Proclus' eighteen arguments to the contrary, which are discussed in eighteen chapters. Chapters 6-8 are translated in this volume.

This is a post-Aristotelian Greek philosophical text, written at a crucial moment in the defeat of paganism by Christianity, AD 529, when the Emporor Justinian closed the pagan Neoplatonist school in Athens. Philoponus in Alexandria was a brilliant Christian philosopher, steeped in Neoplatanism, who turned the pagans' ideas against them. Here he attacks the most devout of the earlier Athenian pagan philosophers, Proclus, defending the distinctively Christian view that the universe had a beginning against Proclus' eighteen arguments to the contrary, which are discussed in eighteen chapters. Chapters 1-5 are translated in this volume.

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 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. Includes notes on the text, and English-Greek glossary and index.

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.

Until the launch of this series over ten 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. Over 30 volumes have now appeared in the series, which is planned in some 60 volumes altogether. In this, one of the most original ancient texts on sense perception, Philoponus, the sixth century AD commentator on Aristotle, considers how far perceptual processes are incorporeal. Colour affects us in the same way as light which, passing through a stained glass window, affects the air, but colours only the masonry beyond. Sounds and smells are somewhat more physical, travelling most of the way to us with a moving block of air, but not quite all the way. Only the organ of touch takes on the tangible qualities perceived, because reception of sensible qualities in perception is cognitive, not physical. Neither light nor the action of colour involves the travel of bodies. Our capacities for psychological activity do not follow, nor result from, the chemistry of our bodies, but merely supervene on that. On the other hand, Philoponus shows knowledge of the sensory nerves, and he believes that thought and anger both warm us. This is used elsewhere to show how we can tell someone else's state of mind.