In this article the author analyzes a fifteenth-century Arabic reform of the Ptolemaic model for Mercury. The author of the reform was the Central Asian – Ottoman astronomer ‘Alā” al-Dīn al-Qushjī (d. 1474 A.D.) who, in his youth, had been instructed in the mathematical sciences by none other than the famous Central Asian monarch Ulugh Beg (1394–1449). Although the astronomers of Ulugh Beg's circle are known to have produced extensive astronomical Persian tables, no one other than Qushjī has been yet identified to have produced a theoretical text devoted to the criticism, let alone the reform, of the Ptolemaic mathematical planetary models. The present article on Qushji's reform of the Ptolemaic model for Mercury includes a critical first edition of Qushji's Arabic text, an English translation, and a historical and technical commentary.

The article describes several representations of Alexander the Great which were current in medieval Arabic learned circles and proposes some ideas on the genesis of these representations in the Greek and Syriac civilizations: 1) Alexander as moralist; 2) Alexander as a mystical philosopher who knew the mysterious links governing the cosmos; 3) Alexander as a monotheist philosopher who was charged with responsibility for the Ğihād; 4) Alexander as a cunning politician.

In his commentary on the first Aphorism of Hippocrates Maimonides lists the seven parts of medicine. Scholars have studied the relation of this text to the work of al-Fārābī. In particular, they have focused on the Iḥṣāʼ al-ʼulῡm, which in its present form does not contain a discussion of medicine, and on al-Fārābīʼs Risāla fi al-ţibb. The article examines the medieval Hebrew versions of the Iḥṣāʼ al-ʽūlum (versions made by Falaqera, Qalonimos and Rieti). On the basis of these versions, it is argued that there existed a version of the Ihşāʼ al-ʽulūm which did contain a section on medicine; that the Risala fi al-ţibb could have originated in such a fuller version of the Ihsa' al-'ulum; and that Maimonides's ultimate source for his classification of medicine was probably the Iḥṣāʼ al-ʽulūm. An appendix to the paper examines Maimonides's references to Galen and to Abū Bakr al- Rāzī. These references show Maimonides's perception of al-Fārābīʼs view of physicians who claim to be philosophers.

This paper presents the Arabic text, the French translation and an analysis of al-Sijzīʼs treatise (second half of the tenth century), the Book of Measurement of Spheres by Spheres. In this text, al-Sijzī divides the cube into several sub-cubes and parallelopipedes, thus offering us a stereometric interpretation of algebraic identities of the third degree usually credited to mathematicians of the sixteenth and seventeenth centuries. However, this was not al-Sijzīʼs motivation for writing this treatise; rather it was his theoretical interest in the Euclidian concept of the “power” of a segment, an interest which is clearly geometric rather than algebraic. This has led al-Sijzī to the notion of dimension, at least in outline.