Among the phenomena examined in the Meteorologica, some, although they are sublunar, are too distant to be accessible to direct study. To remedy this situation, it was necessary to develop procedures and methods which could allow observation, and above all the geometrical control of observations. The eventual result of this research was to detach the phenomenon under consideration from meteorology, and to insert it within optics or astronomy. Abū Sahl al-Qūhī (second half of the tenth century), composed a treatise on shooting stars in which he carries out such an insertion. In a second treatise, he deals with another type of observation, intended to measure maritime, terrestrial, and celestial surfaces. Here, the author studies al-Qūhī's contribution and gives the editio princeps of these two treatises, as well as their translation.

Among the phenomena examined in the Meteorologica, some, although they are sublunar, are too distant to be accessible to direct study. To remedy this situation, it was necessary to develop procedures and methods which could allow observation, and above all the geometrical control of observations. The eventual result of this research was to detach the phenomenon under consideration from meteorology, and to insert it within optics or astronomy. Abū Sahl al-Qūhī (second half of the tenth century), composed a treatise on shooting stars in which he carries out such an insertion. In a second treatise, he deals with another type of observation, intended to measure maritime, terrestrial, and celestial surfaces. Here, the author studies al-Qūhī's contribution and gives the editio princeps of these two treatises, as well as their translation.

Avicenna refers on a number of occasions in his Book of the Syllogism to “the eminent later scholar” (al-fā[ddotu]il min al-muta'a[hbrevu][hbrevu]irī). At least three recent studies have argued or assumed that this eminent later scholar is Alexander of Aphrodisias. It is argued in this article that Avicenna is in fact referring to Alfarabi. This has consequences for reconstructing the lost first part of Alfarabi's Great Commentary on the Prior Analytics, for highlighting certain aspects of Alfarabi's logical doctrines, and for understanding more about the relation between Avicenna and Alfarabi in matters logical.

A part of chapter 1, Book II of the Physics of the šif¯' is dedicated to the aristotelian definition of motion (Physics III, 1, 201a10-11). The developments to which the treatment of this question gives rise are distinctive of the Avicennian style in his Physics. By assuming the notion of double entelechy, Avicenna is following the most classical exegetical tradition. However, by setting a correspondence between the double entelechy and the double notion of motion: 1) motion as an intermediary state, which can be ascribed to a moving object at any instant of its trajectory, and 2) motion as a traversal of a given distance, which cannot be ascribed to the moving object, but at the end-point of its trajectory, Avicenna gives a new content to a lieu commun of the exegetical tradition.

The autobiography witnesses a significant evolution in Avicenna's approach to Aristotle's Metaphysics during the years of his education. It clearly shows that, at a certain point of his philosophical training, Avicenna faced the entire text of the Metaphysics, was puzzled by its extent and complexity, and found in a treatise by al-Fārābī a guide for its understanding. But, albeit less perspicuously, the autobiography also suggests that this was not Avicenna's first encounter with the Metaphysics. Avicenna dealt with Aristotle's work in a previous stage of his studies as well. Then, however, he did not read the Metaphysics in its entirety, but, rather, focused only on its essential parts and some commentaries thereupon. The parts of the Metaphysics that Avicenna read in this earlier stage were books Alpha Elatton and Lambda, as constituting the natural theology of Aristotle's work. He neglected, on the contrary, the books corresponding to its ontological part. The special attention to Alpha Elatton and Lambda and the close connection between these two books in a theological context were peculiar traits of al-Kindī's approach to Aristotle's Metaphysics. Therefore, the evolving approach to Aristotle's Metaphysics that Avicenna's autobiography witnesses can properly be described as a passage from the Kindian to the Farabian way of interpretation.

Na[sdotu]īr al-Dīn al-[Tdotu]ūsī, Memoir on Astronomy (al-Tadhkira fī ‘ilm al-hay’a, Edited with Introduction, Translation and Commentary by F.J. Ragep, 2 vols., XV + 656 + XV pp., figs., index. New York - Berlin - Heidelberg..., Springer Verlag, 1993 (Sources in the History of Mathematics and Physical Sciences, 12).

[Sdotu]adr al-Sharī‘a. An Islamic Response to Greek Astronomy: Kitāb Ta‘dīl Hay’at al-Aflāk of [sdotu]adr al-Sharīa, Edited with Translation and Commentary by Ahmad S. Dallal, X + 461 pp., figs., index. Leiden - New York - Köln, E.J. Brill, 1995 (Islamic Philosophy, Theology & Science, Texts and Studies, vol. 23).