The commentary of Alexander of Aphrodisias on Aristotle's Prior Analytics 1.8-22 is the main ancient commentary, by the 'greatest' commentator, on the chapters of the Prior Analytics in which Aristotle invented modal logic - the logic of propositions about what is necessary or contingent (possible). In this volume, which covers chapters 1.8-13, Alexander of Aphrodisias reaches the chapter in which Aristotle discusses the notion of contingency. Also included in this volume is Alexander's commentary on that part of Prior Analytics 1.17 which explains the conversion of...

In On the Soul 3.1-5, Aristotle goes beyond the five sense to the general functions of sense perception, the imagination and the so-called active intellect, the of which was still a matter of controversy in the time of Thomas Aquinas.
In his commentary on Aristotle's text, 'Simplicius' insists that the intellect in question is not something transcendental but the human rational soul. He denies both Plotinus' view that a part of the soul has never descended from uninterrupted contemplation of the Platonic Forms, and Proclus' view that the soul cannot be changed in its substance...

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...

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...

In his work On Sense Perception, Aristotle discusses the material conditions of perception, starting with the sense organs and moving to the material basis of colour, flavour and odour. His Pythagorean account of hues as a ratio of dark to light was enthusiastically endorsed by Goethe against Newton as being true to the painter's experience. Aristotle finishes with three problems about continuity. First, in what sense are indefinitely small colour patches or colour variations perceptible? Secondly, which perceptible leap discontinuously like light to fill a whole space, which have to...

In Categories chapters 7 and 8 Aristotle considers his third and fourth categories - those of Relative and Quality. Critics of Aristotle had suggested for each of the non-substance categories that they could really be reduced to relatives, so it is important how the category of Relative is defined. Aristotle offers two definitions, and the second, stricter, one is often cited by his defenders in order to rule out objections. The second definition of relative involves the idea of something changing its relationship through a change undergone by its correlate, not by itself. There were...

' Simplicius'] moral interpretation of Epictetus is preserved in the library of nations, as a classic book, most excellently adapted to direct the will, to purify the heart, and to confirm the understanding, by a just confidence in the nature both of God and man.'
Edward Gibbon

'This book, written by a ""pagan"" philosopher, makes the most Christian impression conceivable. The betrayal of all reality through morality is here present in its fullest splendour - pitiful psychology, the philosopher is reduced to a country parson. And Plato is to blame for all of...

Aristotle devotes books 8-9 of the Nicomachean Ethics to friendship, distinguishing three kinds: a primary kind motivated by the other's character; and other kinds motivated by utility or pleasure. He takes up Plato's idea that one knows oneself better as reflected in another's eyes, as providing one of the benefits of friendship, and he also sees true friendship as modelled on true self-love. He further compares friendship with justice, and illustrates the ubiquity of friendship by referring to the way in which we help wayfarers as if they were kin (oikeion), a word he takes from...

Proclus' On the Existence of Evils is not a commentary, but helps to compensate for the dearth of Neoplatonist ethical commentaries. The central question addressed in the work is: how can there be evil in a providential world? Neoplatonists agree that it cannot be caused by higher and worthier beings. Plotinus had said that evil is matter, which, unlike Aristotle, he collapsed into mere privation or lack, thus reducing its reality. He also protected higher causes from responsibility by saying that evil may result from a combination of goods. Proclus objects: evil is real, and not a...

Is there such a thing as three-dimensional space? Is space inert or dynamic? Is the division of time into past, present and future real? Does the whole of time exist all at once? Does it progress smoothly or by discontinuous leaps?
Simplicius surveys ideas about place and time from the preceding thousand years of Greek Philosophy and reveals the extraordinary ingenuity of the late Neoplatonist theories, which he regards as marking a substantial advance on all previous ideas.