commentaries on Aristotle the term commonly used for the Greek commentaries on Aristotle that take up about 15,000 pages in the Berlin Commentaria in Aristotelem Graeca (1882–1909), still the basic edition of them. Only in the 1980s did a project begin, under the editorship of Richard Sorabji, of King’s College, London, to translate at least the most significant portions of them into English. They had remained the largest corpus of Greek philosophy not translated into any modern language.
Most of these works, especially the later, Neoplatonic ones, are much more than simple commentaries on Aristotle. They are also a mode of doing philosophy, the favored one at this stage of intellectual history. They are therefore important not only for the understanding of Aristotle, but also for both the study of the pre-Socratics and the Hellenistic philosophers, particularly the Stoics, of whom they preserve many fragments, and lastly for the study of Neoplatonism itself – and, in the case of John Philoponus, for studying the innovations he introduces in the process of trying to reconcile Platonism with Christianity.
The commentaries may be divided into three main groups. (1) The first group of commentaries are those by Peripatetic scholars of the second to fourth centuries A.D., most notably Alexander of Aphrodisias (fl. c.200), but also the paraphraser Themistius (fl. c.360). We must not omit, however, to note Alexander’s predecessor Aspasius, author of the earliest surviving commentary, one on the Nicomachean Ethics – a work not commented on again until the late Byzantine period. Commentaries by Alexander survive on the Prior Analytics, Topics, Metaphysics I–V, On the Senses, and Meteorologics, and his now lost ones on the Categories, On the Soul, and Physics had enormous influence in later times, particularly on Simplicius. (2) By far the largest group is that of the Neoplatonists up to the sixth century A.D. Most important of the earlier commentators is Porphyry (232–c.309), of whom only a short commentary on the Categories survives, together with an introduction (Isagoge) to Aristotle’s logical works, which provoked many commentaries itself, and proved most influential in both the East and (through Boethius) in the Latin West. The reconciling of Plato and Aristotle is largely his work. His big commentary on the Categories was of great importance in later times, and many fragments are preserved in that of Simplicius. His follower Iamblichus was also influential, but his commentaries are likewise lost. The Athenian School of Syrianus (c.375–437) and Proclus (410–85) also commented on Aristotle, but all that survives is a commentary of Syrianus on Books III, IV, XIII, and XIV of the Metaphysics. It is the early sixth century, however, that produces the bulk of our surviving commentaries, originating from the Alexandrian school of Ammonius, son of Hermeias (c.435–520), but composed both in Alexandria, by the Christian John Philoponus (c.490–575), and in (or at least from) Athens by Simplicius (writing after 532). Main commentaries of Philoponus are on Categories, Prior Analytics, Posterior Analytics, On Generation and Corruption, On the Soul I–II, and Physics; of Simplicius on Categories, Physics, On the Heavens, and (perhaps) On the Soul. The tradition is carried on in Alexandria by Olympiodorus (c.495–565) and the Christians Elias (fl. c.540) and David (an Armenian, nicknamed the Invincible, fl. c.575), and finally by Stephanus, who was brought by the emperor to take the chair of philosophy in Constantinople in about 610. These scholars comment chiefly on the Categories and other introductory material, but Olympiodorus produced a commentary on the Meteorologics. Characteristic of the Neoplatonists is a desire to reconcile Aristotle with Platonism (arguing, e.g., that Aristotle was not dismissing the Platonic theory of Forms), and to systematize his thought, thus reconciling him with himself. They are responding to a long tradition of criticism, during which difficulties were raised about incoherences and contradictions in Aristotle’s thought, and they are concerned to solve these, drawing on their comprehensive knowledge of his writings. Only Philoponus, as a Christian, dares to criticize him, in particular on the eternity of the world, but also on the concept of infinity (on which he produces an ingenious argument, picked up, via the Arabs, by Bonaventure in the thirteenth century). The Categories proves a particularly fruitful battleground, and much of the later debate between realism and nominalism stems from arguments about the proper subject matter of that work. The format of these commentaries is mostly that adopted by scholars ever since, that of taking one passage, or lemma, after another of the source work and discussing it from every angle, but there are variations. Sometimes the general subject matter is discussed first, and then details of the text are examined; alternatively, the lemma is taken in subdivisions without any such distinction. The commentary can also proceed explicitly by answering problems, or aporiai, which have been raised by previous authorities. Some commentaries, such as the short one of Porphyry on the Categories, and that of Iamblichus’s pupil Dexippus on the same work, have a ‘catechetical’ form, proceeding by question and answer. In some cases (as with Wittgenstein in modern times) the commentaries are simply transcriptions by pupils of the lectures of a teacher. This is the case, for example, with the surviving ‘commentaries’ of Ammonius. One may also indulge in simple paraphrase, as does Themistius on Posterior Analysis, Physics, On the Soul, and On the Heavens, but even here a good deal of interpretation is involved, and his works remain interesting. An important offshoot of all this activity in the Latin West is the figure of Boethius (c.480–524). It is he who first transmitted a knowledge of Aristotelian logic to the West, to become an integral part of medieval Scholasticism. He translated Porphyry’s Isagoge, and the whole of Aristotle’s logical works. He wrote a double commentary on the Isagoge, and commentaries on the Categories and On Interpretation. He is dependent ultimately on Porphyry, but more immediately, it would seem, on a source in the school of Proclus. (3) The third major group of commentaries dates from the late Byzantine period, and seems mainly to emanate from a circle of scholars grouped around the princess Anna Comnena in the twelfth century. The most important figures here are Eustratius (c.1050–1120) and Michael of Ephesus (originally dated c.1040, but now fixed at c.1130). Michael in particular seems concerned to comment on areas of Aristotle’s works that had hitherto escaped commentary. He therefore comments widely, for example, on the biological works, but also on the Sophistical Refutations. He and Eustratius, and perhaps others, seem to have cooperated also on a composite commentary on the Nicomachean Ethics, neglected since Aspasius. There is also evidence of lost commentaries on the Politics and the Rhetoric. The composite commentary on the Ethics was translated into Latin in the next century, in England, by Robert Grosseteste, but earlier than this translations of the various logical commentaries had been made by James of Venice (fl. c.1130), who may have even made the acquaintance of Michael of Ephesus in Constantinople. Later in that century other commentaries were being translated from Arabic versions by Gerard of Cremona (d.1187). The influence of the Greek commentary tradition in the West thus resumed after the long break since Boethius in the sixth century, but only now, it seems fair to say, is the full significance of this enormous body of work becoming properly appreciated. See also ARISTOTLE , BOETHIUS , NEOPLA- TONISM , PORPHYRY. J.M.D.