The ArgumentIt was commonly accepted in the middle ages that void within or outside the world is impossible. The paper presents a quite unusual conception of void, which is described in Yeda'aya ha-Penini's commentary on Ibn Rushd's epitome on Aristotle's Physics. According to this conception there is a thin layer of void between the water and the inner surface of the container. Ha-Penini describes two versions of this conception. According to one version this void layer is three-dimensional but thin, according (...) to the other it is two-dimensional. The first part of the paper shows how ha-Penini “corrects” the text of Ibn Rushd, putting into it ideas which were unknown to Ibn Rushd. It is argued that, though the two views are rejected by Ibn Rushd, ha-Penini himself partly accepts (his version of) these views. The second part of the paper argues that ha-Penini could not have found these views in the Arabic-Hebrew tradition, and it seems that he relied on Christian sources. If this is indeed so, the paper presents an example of acquaintance of Hebrew scholars in southern France with Scholastic science in the first half of the fourteenth century. (shrink)

This dissertation offers a new and comprehensive analysis of Abū Naṣr al-Fārābī's cosmology by focusing on various important issues that have been largely neglected by the modern scholarship. It provides an examination of the physical, metaphysical, and astronomical aspects of al-Fārābī's cosmology by adopting a multidisciplinary approach that takes into account the history of philosophy and the history of astronomy. Accordingly, my dissertation explores how al-Fārābī attempted to reconcile features of Ptolemaic astronomy with Aristotelian and Neoplatonic theories, an endeavor which (...) resulted in the formulation of innovative cosmological ideas. Chapters I and II provide background information on al-Fārābī's activity as a commentator and his relation to the Greek commentatorial tradition and assess the relevant primary sources. In addition, they examine al-Fārābī's approach to cosmology and his scientific method in terms of both the Ptolemaic astronomical tradition and the Aristotelian corpus. Chapter III addresses problems related to the structure of al-Fārābī's cosmology, especially the origin of his ennadic cosmological model and his spherology. Particular attention is devoted to the question of how Aristotle's unmoved movers and Ptolemy's astronomical theories are reconciled. Chapters IV, V, and VI analyze the place of celestial matter, intellect, and motion respectively in al-Fārābī's cosmology and attempt to redefine the second teacher's relation to the various trends of Greek philosophy. The study stresses al-Fārābī's connection with the Neoplatonic and Peripatetic currents, particularly with thinkers such as Alexander of Aphrod. (shrink)