Deux opuscules nous sont parvenus de Thābit ibn Qurra sur la théorie des parallèles. Ces deux traités sont bien connus et ont fait déjà l'objet de plusieurs commentaires et traductions. Nous pensons reprendre ici aussi bien l'édition que la traduction et le commentaire pour mieux situer la contribution de Thābit ibn Qurra après la publication récente de ses œuvres en astronomie et en mathématiques.

Although numerous studies have been conducted on the Optics (Kitāb al-Manāzir) of Alhazen (al-Hasan ibn al-Haytham, d. 1040 C.E.), and on its reception, assimilation and maturation within the course of development of the perspectivae traditions in the history of science and art, ambiguities do hitherto still surround the epistemological and ontological entailments of his theory of visual perception. In addressing this question, our inquiry herein is principally philosophical in scope and our textual reading combines exegesis with hermeneutics. While we observe the delicate procedures of historiography and philology, we do not unguardedly assume that they are exhaustive of all rigorous methods of thoughtful investigation. Moreover, in heeding the internal coherence of Alhazen's text, we do not simply lock his views within reductive contextual chronologies, or readily confine them to epochal matters of textual transmission. Our endeavour is therefore not exclusively set in view of serving the purposes of archival documentation, even if we preserve a thorough and sound sense of historicity. We ultimately recognize the philosophical pertinence of numerous subtle leitmotifs within Alhazen's thinking that speak to us in an effective timely manner, which is significantly relevant in its attuned bearings to the thrust of phenomenological theories of perception.

In an influential article, A. I. Sabra identified an intellectual trend from twelfth and thirteenth-century Andalusia which he described as the ‘‘Andalusian revolt against Ptolemaic astronomy.” Philosophers such as Ibn Rushd (d. 1198 C. E.), Ibn Tufayl (d. 1185), and Maimonides (d. 1204) objected to Ptolemy’s (fl. 125–50) theories on philosophic grounds, not because of shortcomings in the theories' predictive accuracy. Sabra showed how al-Bitrūjī's (fl. 1200) Kitāb al-Hay'a (The Book of Astronomy) attempted to account for observed planetary motions in a way that met the philosophic standards of those philosophers and others. In Nūr al-‘ālam (Light of the World), the subject of this article, Joseph ibn Joseph ibn Nahmias (fl. ca. 1400) endeavoured to improve upon al-Bitrūjī’s models. Levi Ben Gerson's (1288–1344) Hebrew writings on astronomy criticized al-Bitrūjī, but Ibn Nahmias did not mention them. Nūr al-‘ālam deserves attention, too, because it is the first Arabic text on theoretical astronomy by a Jewish author to come to light. In the body of this article, I will describe and analyze Ibn Nahmias’ theory, from Nūr al-‘ālam, for the motion of the sun.

From the late thirteenth to the early seventeenth century, the process of visual imaging was understood in the Latin West as an essentially subjective act initiated by the eye and completed by the brain. The crystalline lens took center stage in this act, its role determined by its peculiar physical and sensitive capacities. As a physical body, on the one hand, it was disposed to accept the physical impressions of light and color radiating to it from external objects. As a sensitive body, on the other hand, it was enabled by the visual spirit flowing to it from the brain to feel those impressions visually. Acting as a sentient selector of visual information, the lens transformed the brute physical impressions of light and color into visual impressions. These, in turn, gave rise to perceptual “depictions” that were passed back along the stream of visual spirits to the brain. Known in Scholastic parlance as “intentional species,” these depictions served as virtual representations of their generating objects. As such, they provided the wherewithal not only for perception, but also for conception and cognition.

Dans ses traités consacrés à l'âme, Ibn Sīnā élabore une doctrine complexe de la perception dont l'analyse permet de dégager deux conceptions distinctes de l'image. L'une détermine l'image comme une doublure du réel, qui re-présente quelque chose, et tient lieu d'une chose absente. Cette caractérisation de l'image comme un double et une entité matérielle qui se forme dans les puissances-organes comme par réification s'inscrit dans la conception antique et médiévale de l'image. L'image, dans l'horizon épistémique de l'Antiquité et du Moyen Âge, n'est jamais conçue, en effet, que dans sa relation à ce qu'elle représente. Le statut ontologique de cette image-reflet est celui d'un double: c'est un reflet que sa matérialité rend manifeste.

The starting-point and, at the same time, the foundation of recent scholarship on the Arabic translations of Aristotle's Metaphysics are Maurice Bouyges' excellent critical edition of the work in which the extant translations of the Metaphysics are preserved – i.e. Averroes' Tafsīr (the so-called “Long Commentary”) of the Metaphysics – and his comprehensive account of the Arabic translations and translators of the Metaphysics in the introductory volume. Relying on the texts made available by Bouyges and the impressive amount of philological information conveyed in his edition, subsequent scholars have been able to select and focus on more specific topics, providing, for example, a closer inspection of the Arabic translations of the single books of the Metaphysics (books A, α, and Λ in particular), or a detailed comparison of some of these translations with the original text of the Metaphysics. A new trend of research in recent times has been the study of these versions as part of the wider context of the Graeco-Arabic translation movement.

Sa‘d ibn Mansūr Ibn Kammūna was a Jewish physician-philosopher of Iraqi origin who flourished in the thirteenth century (d. 1284). Best known for his original and comparative inquiry into the three monotheistic faiths, whose publication nearly cost him his life, he was, in fact, a very productive thinker, and a scholar well in tune with developments in the philosophy and science of his day. He had personal contact with some leading intellectuals, and he played an important role in the diffusion of some new trends of thought. His legacy, in the form of commentaries, correspondence, and original works, is now being studied in earnest.

According to Tāj al-Dīn al-Subkī (d. 771 / 1370), al-Ghazālī (d. 505 / 1111) was the renewer (mujaddid) of the Muslim faith at the end of the 5th / 11th century, whereas al-Rāzī (d. 606 /1210) was the renewer of faith at the end of the 6th / 12th century. That al-Ghazālī deserves such an honour can hardly be disputed, and his importance in the history of Islamic thought is generally recognised. However, the same cannot, as easily, be said of al-Rāzī, whose historical significance is far from being truly appreciated, and some of the most important books of whom still await publication. Much is known about his views on particular philosophical and theological problems, and about the historical backgrounds to, and the relations amongst, some of these views. Some rather general observations on his thought are also common; for instance, that he is a heavily philosophising Ash‘arī mutakallim, a master dialectician, and an influential critic of Ibn Sīnā.

Matthias Schramm, a well-known historian of science and professor at the University of Tübingen from 1966 to 1996, died in Dusslingen near Tübingen on 24 January 2005, shortly before his 77th birthday. He was born on 6 February 1928 in Paris as a child of painters. Due to wartime difficulties, most of his education was acquired at home. In spite of this, he passed the examination of a high-school prior to his matriculation (Abitur). Although Schramm's school had a pure classical orientation (humanistisches Gymnasium), he read on his own initiative Euclid in Greek.