During the Middle Ages Aristotle’s treatises were accessible to intellectuals via translations and commentaries. Among his works on natural philosophy, the zoological books received relatively little scholarly attention, though several medieval commentators carefully studied Aristotle’s investigations of the animal kingdom. Averroes completed in 1169 a commentary on an Arabic translation of Aristotle’s Parts of Animals and Generation of Animals. In 1323 Gersonides completed his supercommentary on a Hebrew translation of Averroes’ commentary. This article examines how these two medieval commentators interpret (...) the first book of Aristotle’s Parts of Animals, at the center of which stand methodological questions regarding the study of animals. Aristotle’s discussion of classification is presented by Averroes and Gersonides in light of an epistemological debate concerning the requisite method for scientific inquiries and discoveries. Sense perception is contrasted with rational reasoning, and ultimately a combined method is proposed, sense perception maintaining supremacy. These commentators outline a clear link between the systematic arrangement of animal species as offered by Aristotle, and his subsequent logical demonstrations which, according to them, form the core of biological investigations. (shrink)

Levi ben Gerson was a medieval astronomer who responded in an unusual way to the Ptolemaic tradition. He significantly modified Ptolemy’s lunar and planetary theories, in part by appealing to physical reasoning. Moreover, he depended on his own observations, with instruments he invented, rather than on observations he found in literary sources. As a result of his close attention to the variation in apparent planetary sizes, a subject entirely absent from the Almagest, he discovered a new phenomenon of Mars and (...) noticed a serious flaw in Ptolemy’s treatment of the Moon. (shrink)

During the Middle Ages Aristotle's treatises were accessible to intellectuals via translations and commentaries. Among his works on natural philosophy, the zoological books received relatively little scholarly attention, though several medieval commentators carefully studied Aristotle's investigations of the animal kingdom. Averroes completed in 1169 a commentary on an Arabic translation of Aristotle's Parts of Animals and Generation of Animals. In 1323 Gersonides completed his supercommentary on a Hebrew translation of Averroes' commentary. This article examines how these two medieval commentators interpret (...) the first book of Aristotle's Parts of Animals, at the center of which stand methodological questions regarding the study of animals. Aristotle's discussion of classification is presented by Averroes and Gersonides in light of an epistemological debate concerning the requisite method for scientific inquiries and discoveries. Sense perception is contrasted with rational reasoning, and ultimately a combined method is proposed, sense perception maintaining supremacy. These commentators outline a clear link between the systematic arrangement of animal species as offered by Aristotle, and his subsequent logical demonstrations which, according to them, form the core of biological investigations. (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)

: To honor Bernard Goldstein, this article highlights in the "Defense of Theon against George of Trebizond" by Regiomontanus (1436-1476) themes that resonate with leading strands of Goldstein's scholarship. I argue that, in this poorly-known work, Regiomontanus's mastery of Ptolemy's mathematical astronomy, his interest in making astronomy physical, and his homocentric ideals stand in unresolved tension. Each of these themes resonates with Gold- stein's fundamental work on the Almagest, the Planetary Hypotheses, and al-Bitruji's Principles of Astronomy. I flesh out these (...) tensions with an intriguing interpretation of the history of astronomy, in which Regiomontanus contrasts the two-dimensional "eccentric astronomy" attributed to the Almagest and the Arabs with the three-dimensional spheres of the "later" astronomers. A similar contrast reappears when Regiomontanus portrays as a "fictitious art" an astronomy that does not go beyond the accommodation of computations to the appearances. To conclude, I use Regiomontanus's expression to reinstate (pace Goldstein and Barker in this journal, 1998) fictionalism as an actor's category in Osiander and sixteenth-century astronomy. (shrink)