According to Philoponus, the activity of drawing syllogisms is a dynamic operation. Following the classical idea that actions are specified by their objects and habitual powers by their actions, Philoponus concludes that only a dynamic power can elicit the act of syllogizing. This power is identified with discursive reasoning (dianoia). Imagination, on the contrary, is a static power, that cannot elicit that particular motion of drawing a syllogistic inference. The issue, however, is not entirely uncontroversial, because Ammonius maintains that sophistical (...) syllogisms can only be formed by imagination, since they involve “empty concepts” as terms and only imagination can form such concepts. In this paper I will reconstruct Philoponus’ and Ammonius’ theories about the “activity” of syllogizing, and I shall explain how Philoponus can deal with sophistical syllogisms in a consistent way. (shrink)

L’étude d’un document épigraphique antinoïte, jusqu’ici négligé, suggère que le géomètre Serenus, auteur de deux traités "Sur la section du cylindre" et "Sur la section du cône", vivait au début du IIIe siècle. Le réexamen plus précis d’un certain nombre d’éléments tirés tant des traités de Serenus que de la tradition indirecte permet de faire de celui-ci le continuateur tardif d’une tradition de recherches sur les coniques très liée à la catoptrique, remontant aux travaux pré-apolloniens sur la question menés autour (...) de Conon de Samos et de Pythion de Thasos. Cette hypothèse pose, corrélativement, le problème de la nature du platonisme de Serenus: on l’examine à la lumière du constructivisme de Ménechme. Enfin, la prise en compte d’un détail de la tradition arabe des "Coniques" d’Apollonius permet de préciser un élément dans la transmission textuelle des deux traités de Serenus. (shrink)

One important mode of philosophical expression from the end of the Hellenistic period and into Late Antiquity was the philosophical commentary. During this time Plato and Aristotle were regarded as philosophical authorities and their works were subject to intense study. This entry offers a concise account of how the revival of interest in the philosophy of Aristotle that took place towards the end of the Hellenistic period eventually developed into a new literary production: the philosophical commentary. It also follows the (...) commentary tradition into Late Antiquity in order to account for the vitality and richness of this tradition. The reader should keep in mind that the study of Aristotle in the form of the commentary did not mean the cessation of genuine philosophical thought. Quite the contrary: authors customarily used the commentary format not only to expound the works of Aristotle, but also as a vehicle for original philosophical theorizing. One consequence of this approach was that, at least at the beginning, the return to the works of Aristotle did not involve the.. (shrink)