Gersonides was a highly original Jewish philosopher, scientist, and biblical exegete, active in Provence in the first half of the fourteenth century. Ruth Glasner explores his impressive achievements, and argues that the key to understanding his originality is his perspective as an applied mathematical scientist.

The Hebrew text On the Heavens and the World, ascribed to Ibn S, is an interesting and intriguing composition. It dates from the 13th century and was quite influential. It is not a translation of any text of Ibn S known to us, but is related to the Latin De celo et mundo, which appears in the 1508 Venice edition of translations of Ibn S. The Latin and Hebrew texts differ widely and the relation between them is far from being (...) clear. Both are in sixteen chapters, the titles of the chapters are the same, but the texts are only roughly similar. The Hebrew text often offers short, incomplete summaries of the Latin arguments. On the other hand it includes many passages which have no parallel in the Latin. There are two possible explanations of the perplexing relationship between the two texts: either that there was more than one version of the Latin text, or that the translator, Shlomo ben Moshe of Laguiri wrote a kind of paraphrase. The paper shows that the second explanation is correct and offers a preliminary study of the sources and the aims of the Hebrew text. (shrink)

Ruth Glasner presents an illuminating reappraisal of Averroes' physics.

The essence of the theory of minima naturalia is the contention that a physical body is not infinitely divisible qua that specific body. A drop of water cannot be divided again and again and still maintain its “wateriness”. There are several statements in Aristotle's Physics which suggest such an interpretation, and the theory of minima naturalia is commonly considered to have originated in the thirteenth century as an interpretation of these statements. The present paper is a preliminary presentation of the (...) role of Ibn Rushd in the evolution of the theory, hitherto neglected. His theory developed not only as an elaboration on the “suitable” statements of Aristotle, but mainly as an attempt to solve the difficulties raised by Aristotle's thesis that body and motion are continuous, infinitely divisible entities and are associated qua such. According to Ibn Rushd's interpretation, body and motion are associated not qua being continuous but qua having indivisible minimal parts. It seems that Epicurus' and Ibn Rushd's theories of minima developed as responses to Physics VI and offer modifications of classical atomism and of classical Aristotelianism , which to a certain extent reduce the gap between these two systems. (shrink)

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)