Abstract

According to Andronicus of Rhodi’s edition of Aristotle’s works in the second half of the first century BCE, the two books of De generatione et corruptione follow De caelo and antecede Metereologica. The three kinds of changes in addition to motion (dealt with in Physica and De caelo) are the main topics of De generatione as well as the attribution either to the four elements (material cause) or to the motion of the sun in the ecliptic (efficient cause) of the origin of such changes. They are: (a) generation and corruption when only the primary matter persists, while substantial form changes; (b) alteration, when substance persists and only qualitative properties change; (c) growth and diminution when change is limited to quantitative properties. Other very important physical notions such as action and passion, mixture and the role of simple bodies in mixed ones are as well discussed. This work reached the Latin middle age through the two main channels through which Aristotle’s work spread in the Latin West, the Greek, and the Arabic. From the latter the medieval commentators borrowed a very useful instrument to get a better acquaintance with the topics discussed in Aristotle’s work: Averroes’ middle commentary, which contains also some hints to Greek commentators. In thirteenth-century Latin commentaries, the need to get to the heart of the text prevails, while in the fourteenth century the discussions of the more urgent philosophical topics overcome the literal explanation.

In the Greek tradition of De generatione et corruptione only Philoponus’ commentary has been preserved; it was translated in Latin by Gerolamo Bagolino in the sixteenth century and published by his son in 1540. Philoponus’ commentary (in which Alexander of Aphrodisias is often quoted) can be considered the model of the following commentaries: it provides precise informations about the Aristotelian context of the topics discussed in De generatione et corruptione (referring to De caelo, Physica, Metereologica, and Metaphysica) and goes deep into some of the most relevant problems dealt with, paying particular attention to the arguments against atomism.

Part of the Latin (the translation of Gerard of Cremona) and the Hebrew (the translation of Zerahyah ben Yshaq, end of the thirteenth century) tradition of Aristotle’s De generatione et corruptione comes from the Arabian translation from the Syriac (by Hunayn b. Islraq, Baghdad, ninth century). In addition to Hunayn’s son Isliaq ben Hunayn’s translation, more Arabic translations are recorded of the lost Greek commentaries by Alexander of Aphrodisias, Themistius, Olimpiodorus, and John Philoponus. In the Islamic world, Avicenna dealt with topics discussed in De generatione et corruptione in the third part of his Shifa’, known in Latin as Sufficientia. The Liber tertius naturalium De generatione was translated only in 1280 in Toledo and it was not very diffused among the Latin scholars. It cannot be properly considered a commentary to Aristotle’s work, even though it deals with topics discussed in De generatione et corruptione. The persistence of the elements in the mixed bodies is one of the main interests in Avicenna’s text: he is convinced that they outlast without any change in mixed bodies, the changes interesting only the accidental forms. This was a problem largely debated in the Latin medieval tradition of De generatione et corruptione and was associated with topics such as the intension and remission and plurality of forms. Avicenna’s solution was known through Averroes’ censures in his De caelo commentary, where he attributes to substantial forms of the elements a weaker ontology (they are an intermediate stage between substantial and accidental forms). The mixed body, therefore, has a special substantial form with qualitative properties resulting from the mixture of the elementary qualities.

Averroes’ (known in the Middle Ages also as “Commentator”) middle commentary on the De generatione et corruptione, translated probably by Michael Scot around 1230, is by far more important for the western Latin tradition of Aristotle’s work. Not only in the commentaries of the more prominent medieval thinkers, but also in the anonymous glosses the Commentator’s interpretation of Aristotle’s text is very often quoted as a sure authority. The difficult and often too concise Latin translations (both from the Arabic and Greek) find in Averroes’ explanatory notes a clear settlement, which consents a wider understanding of Aristotle’s arguments; also the information about the ancient philosophical systems (Plato, Democritus, Leucippus, Anaxagoras, and Empedocles) is widely used by the medieval masters for a more adequate acquaintance with Aristotle’s criticism.

De generatione et corruptione was available to the Latin world in two translations: from the Arabic by Gerard of

Cremona (translatio nova) and from the Greek original by Burgundio of Pisa (translatio vetus). The latter was more widely diffused than the former and was used by Albert the Great, Thomas Aquinas, and Aegidius Romanus. Aegidius used both the old and the new translations, the former being according to him more respectful of Aristotle’s intention.

The content of De generatione et corruptione, as well as of other works by Aristotle, Seneca, and Boethius, circulated since the thirteenth century in a very abridged form, namely as a list of sentences, in which the philosophical topics discussed in the two books were synthetically recorded (Auctoritates Aristotelis, ed. Hamesse, 1974:167-171). This kind of summary of Aristotle’s philosophy was widely used by medieval commentators; very often quotations from De generatione et corruptione as well as from other works follow the text of Auctoritates rather than the original. Its favorable reception is confirmed, moreover, by the medieval tradition of comment on De generatione et corruptione: very often, in fact, the titles of the questions are drawn literally from Auctoritates; to mention only the more common: the persistence ofmatter in generation and corruption, the permanence of similar qualities in generated and corrupted things, the eternity of generation and corruption, reaction following action, the end of motion when properties are acquired by the generated thing, the permanence of primary qualities in the mixed, the elemental qualities, the easier transmutation between bodies with similar properties.

The Auctoritates records some sentences, in addition to those from Aristotle’s text, from the commentaries on De generatione et corruptione by Averroes and Albert the Great which are the two most important contributions to the full appreciation of the topics therein discussed in the Latin world. After the first early diffusion in some of the medical works from the School of Salerno, the fortunes of De generatione et corruptione depend exclusively on its use in the newly established university training.

Together with Averroes’ commentary, the paraphrasis of Aristotle’s De generatione et corruptione by Albert the Great can be considered the most influential contribution to the understanding of Aristotle’s work in the Latin medieval culture. It is exactly this form of commentary which consents a more precise acquaintance with the not always perspicuous Latin translation. Albert’s project, in order to make intelligible Aristotle’s text, is to maintain part of the Latin words and expressions in a wider context of explanation; he reserves, moreover, a deeper analysis to particular topics in his digressions to the textual exegesis. Albert’s choice of the topics to be more carefully considered, has a relevant role in the medieval commentary tradition, since part of the questions raised by the Aristotelian text have their origin in such digressions. According to Albert, De generatione et corruptione is the third and last part of the natural philosophy, having as its object motion concerning either substantial (coming and passing away) or accidental (alteration, augmentation, and diminution) forms of natural bodies. The special object of this part of natural philosophy, as well as its place in the wider domain of physics, is after Albert’s commentary the first problem discussed in commenting on De generatione et corruptione. In several digressions Albert gives a more extensive presentation of Democritus, Leucippus, and Plato’s solutions about the composition and the action of natural bodies, extending Aristotle’s sketchy critical outlines. Albert deals also with the most relevant topics such as the role of potency and matter in generation, the different functions either of substantial forms and qualities in generation and mixture, or of the soul in human growth (where medical notions like the humidum radicale integrate Aristotle’s solution), the permanence of the elements in the mixed bodies, the efficient causality of celestial bodies, in particular the motion of the sun in the ecliptic.

Thomas Aquinas’ commentary on De generatione et corruptione was prepared in Naples and it was, according to William of Tocco’s biography, Thomas’ last work on philosophy. Like other commentaries on Aristotle, it was not finished by Thomas; the lacking part of Book I (from ch. 5) and Book II was provided by Thomas of Sutton. Following his teacher Albert’s lead, Thomas commented on Aristotle’s text, but his explanatory strategy was very different from the paraphrasis of Albert the Great. The philosophical exegesis is introduced by a very careful presentation of Aristotle’s text (divisio textus); the topics discussed by Aristotle are reconsidered and presented in a clear logical form, which permits a deeper acquaintance with philosophical problems (often labeled as questions). Albert’s and Thomas’ commentaries opened the way to the style of widely diffused commentary in the fourteenth-century Latin medieval tradition: the questions on Aristotelian works. In his commentary Thomas is particularly determined on arguing against the materialistic views of the atomists and of Plato, whose geometrical foundations of natural change ignore the importance of the formal structure of natural bodies. Generation and corruption include both matter’s potentiality and substantial form’s actuality. Thomas defends his conviction of the unicity of the substantial form arguing against Avicebron, who maintains in his Fons vitae that a plurality of hierarchically ordered forms is required for every being.

His two commentaries, in the form of explanation and questions respectively, bear witness to Aegidius Romanus’ high interest toward De generatione et corruptione. The questions are limited to part of the first book, while the explanations are for the complete text. This latter commentary is different from both those of Albert the Great and Thomas; Aegidius limits himself programmatically to present Aristotle’s intention and to clarify his way of arguing, reserving for the commentary through questions the discussion of the more important topics raised in the text (only at the beginning we find some topics widely discussed in a similar fashion to the questions commentary). In commenting on Book II Aegidius introduces the wider analysis of philosophical topics as particularly relevant problems (dubia), after having explained Aristotle’s text; these dubia are evidently what would have been reserved for the questions commentary, which Aegidius did not write. This change in the commenting strategy is very important: in the fourteenth century there is an evident distinction between the two kinds of commentary: the explanation is normally limited to an illustration of Aristotle’s text, division of the text, and presentation of the main arguments, while the most relevant topics are discussed through the questions. Aegidius, like Albert and Thomas, is particularly eager in denouncing the limits of Democritus’ and Plato’s convictions about the primary components of natural bodies. In order to grant the infinite divisibility of matter as well as the natural bodies’ possibility of action and passion Aegidius distinguishes between two different sorts of act: actus in fieri and actus in facto esse; the infinite divisibility is not consented in the latter. Discussing on matter Aegidius upholds his theory of the presence in matter of a certain formal element, labeled corporeity, which gives it an indefinite quantitative feature (dimensiones interminatae). In his questions commentary on Book I Aegidius deals with the problems raised by the atomists, with the essential features of generation, alteration, and augmentation, but also with the intension and remission of forms as well as with the limits of continuous motions like alteration.

Both Siger of Brabant and Boethius of Dacia, the two Masters of Arts who in Paris adhered to the new physical and moral doctrines drawn from Aristotle, commented on De generatione et corruptione. Siger limited himself to a concise explanation, while Boethius dedicated a certain number ofshort questions to the main problems discussed in Book I, privileging in the second the action of celestial bodies on the elemental sphere. In the prologue of his commentary Boethius states that man’s highest perfection is in knowing the truth and in behaving rightly. In arguing against Plato’s convictions about the origins of the world, Boethius points out that according to Aristotle cosmos has no beginning, contrary to what is maintained by Christian faith; the same topic is discussed in the last question on Book II as well as in his De aeternitate mundi.

In the fourteenth century, Aristotle’s De generatione et corruptione was often commented on at the University of Paris, where John Buridan, Nicholas Oresme, Albert of Saxony, and Marsilius of Inghen did their best to discuss in the wider context of Aristotelian philosophy the topics raised in the two books. Only John Buridan wrote two commentaries, an explanation commentary (sententia) and a questions commentary, while Nicholas Oresme, Albert and Marsilius limited themselves to the questions commentary; having been published in the early sixteenth century, Albert’s and Marsilius’ commentaries were largely diffused in Renaissance and Early Modern Aristotelian scholastic philosophy. Among others, the English philosopher Walter Burley wrote an explanation commentary, which had a much more limited circulation than his Physics commentary, edited in 1505.

In the fourteenth century, explanation commentaries had a minor role in comparison with those of the thirteenth century; their function was often reduced to the division of the text. The questions commentaries, on the contrary, assumed a complex and articulated structure so much so that a question or a group of questions could be sometimes considered a real treatise (for example, question 11 on Book I of Oresme’s commentary on De generatione et corruptione, dedicated to reaction). In the central section of the questions, commentators usually provide a useful analysis of philosophical terms as well as different possible solutions to the problem(s) discussed; the opening arguments introduce a solution(s) different from that (those) introduced in the central section and the final arguments provide a critical view on this (these) same solution(s). Commentaries on De generatione et corruptione supply in this way a complete abstract of the more debated topics on natural philosophy, including logical and metaphysical aspects.

The French tradition from John Buridan to Marsilius of Inghen will be considered here as a whole. The opening questions of these commentaries enquire the possibility of a science concerning generation and corruption. Together with the traditional distinctions between the different kinds of evidence in mathematics and in physics, a particular interest is devoted to the linguistic analysis, which permits to discriminate generation (interesting absolute, substantial terms) from alteration and augmentation (limited to connotative, accidental terms).

In canvassing the different features of generation and alteration new physical notions are introduced: changes which prelude and prepare generation and corruption (alteratio praevia) are continuous motions, while generation is an instantaneous transformation. These different kinds of changes occasion some very important analyses concerning natural, artificial, and violent transformations and consequently modal notions such as necessary, possible, and impossible. Determinism is ruled out by distinguishing between temporal and eternal necessity, the latter reserved only to the never-changing God’s perfection, while even natural events like lunar eclipses can be frustrated, notwithstanding their apparent necessity.

According to Aristotle, generation is always coupled by corruption: this connection raises problems about the role ofmatter and above all about the relationship between the forms in both generated and corrupted bodies. All the Parisian commentators we are here considering adhere to the unicity of substantial form theory (with the exception of Oresme, who defends double substantial principle in human beings, which according to Marsilius of Inghen is an open adhesion to the plurality theory).

The problem concerning the identity of natural bodies interested in physical changes is raised in debating growth and diminution. Man’s identity is assured by his soul, which is the same through different changes and ages, while in natural elemental bodies it is very hard to point out such a principle, precisely because of the continuous partial or total variations. Identity is a notion that can be properly used only for permanent things, while for successive ones (like those submitted to physical transformations) it can be used only in a larger sense.

The problem of action and passion in natural bodies heralds the last topic of Book I of De generatione et corruptione, namely mixture. In addition to the traditional problems concerning the contact between agent and patient, in these commentaries the model of the diffusion of light (multiplicatio specierum) is assumed as a possible way of accounting for natural action. The atomist theory of change gives the occasion to John Buridan to deal with the possibility of the infinite division. The other commentators, beginning with Nicholas Oresme, introduce new philosophical notions such as intension and extension, referring respectively to the degree of intensity (intensio qualitatis) and to the spreading (quantitas qualitatis) of the quality in the natural body. These are the basilar notions of the De configurationibus qualitatum doctrine to which Nicholas Oresme dedicated a special treatise, which can be considered as one of the most innovative tools in natural philosophy, relying also on geometry and mathematics in order to explain physical changes. The latitude of forms is used in the questions of Book II to research into the ways of interacting of the elemental qualities.

Mixture raises very important problems concerning its natural or violent nature: all the elements, in fact, must be involved in order for a mixed body to be produced. The permanence of the elemental forms in the mixed body, moreover, revive the old contraposition between Avicenna and Averroes, the former against any possibility of change inside substantial forms, the latter more favorable to such a possibility for the elemental forms, exactly to let them survive inside the mixed bodies. In addition to the traditional topics either of intension and remission of forms or of the unicity/plurality of forms, new notions such as the temporal limits of alteration and generation of a mixed body (primum/ultimum instans; maximum/minimum quod sic/quod non) and reaction (the action of the patient on the agent) are introduced in these questions, together with the new mathematical tools to study motion (de proportionibus). In the last question(s) on Book II of De generatione et corruptione of the fourteenth-century Parisian commentaries we are considering here, a very significant change is to be recorded: the problem of the duration ofnatural bodies is analyzed relying on these new tools (temporal limits) rather than on astrological notions, as in the case of Albert the Great’s commentary.

With Lefevre d’Etaples’ Paraphrases, published in Paris in 1501 the tradition of Aristotle’s De generatione et corruptione enters in a new age, in which the need of a more correct acquaintance with the text is more urgent than that with the philosophical topics (also the Commentarii collegii Conimbricensis on De generatione, where the late medieval discussions are very often recorded, have a similar approach).

See also: > Albert the Great > Aristotelianism in the Greek, Latin, Syriac, Arabic, and Hebrew Traditions > Boethius of Dacia > Change and Motion > Gerard of Cremona > Ibn Rushd, Muhammad ibn Ahmad al-Hafid (Averroes) > Ibn Slna, Abu 'All (Avicenna) > John Buridan > John Philoponus > Marsilius of Inghen > Natural Philosophy > Nicholas Oresme > Siger of Brabant > Thomas Aquinas