Fārābī had an Arabic translation of Ptolemy’s Harmonics and was deeply immersed in it. The evidence is internal to Kitāb al-Mūsīqā al-kabīr. A passage can be found at the end of the first book of the madḫal in which Ptolemy is mentioned by name and his treatise on music also receives explicit mention. The puzzle is that, according to Fārābī, Ptolemy acknowledges directly in the Harmonics that he could not discriminate different patterns of attunement by ear, but Ptolemy nowhere makes any comment about his level of musicianship. The best way to understand Fārābī’s puzzling claim is as an inference from Ptolemy’s attempt to disprove Aristoxenus’ argument that the fourth is equal to two and a half tones. The paper argues that the inference is plausible, that Fārābī drew it and that he could not have drawn it without being intimately familiar with Ptolemy’s Harmonics.

Cette étude propose une relecture inédite de la physique élémentaire d’Averroès à partir de trois questions laissées ouvertes par les textes d’Aristote : le statut des qualités premières, l’existence d’une intensité maximale de ces qualités, et la possibilité pour les corps simples d’exister à l’état pur. En croisant les commentaires au De caelo, au De generatione et corruptione et aux Meteorologica, son apport majeur consiste à faire apparaître, dans un corpus souvent lu à travers le seul prisme péripatéticien, l’influence structurante de Galien. En articulant les schèmes hylémorphiques d’Alexandre d’Aphrodise avec la théorie galénique des puissances naturelles, Averroès élabore une théorie du sensible inédite, critique à l’égard d’Avicenne, selon laquelle le cosmos est un système dynamique clos, dans lequel le mélange perpétuel, orchestré par le mouvement céleste, donne lieu à ce que l’on peut appeler une complexion cosmique : non pas un équilibre absolu, mais une somme réglée de complexions relatives, à la mesure de la diversité du sensible.

The “Concession to Avicenna,” also known as the seventh chapter of De substantia orbis, is one of Averroes’s several philosophical attempts to reconcile between the corporeality of the celestial bodies and their eternity. The “Concession” contains a brief and rare nod of approval to Avicenna, which prompted the title under which it circulated. The work, lost in Arabic, survives in Ṭodros Ṭodrosi’s Hebrew translation from 1340, from which Abraham de Balmes’s subsequent Latin translation was made in the early sixteenth century. The present contribution offers, for the first time, an edition of the text in Hebrew and its original Latin translation (before its editorial revision for the 1525 editio princeps), alongside an introduction, a philosophical analysis of the argument, an English translation, and a glossary.