This article aims to present a summary account of the role of Syriac in the transmission of Aristotle's Organon from Greek to Arabic. The main sources for that purpose lie in the Syriac and Arabic translations of Aristotle's works, that were achieved during the period from the 7th to the 9th centuries. Some problems related to these translations are discussed, with more attention paid to the emergence of a technical language of logic.

This article proposes a reconstitution of the philosophical tenor of al-Fārābī's lost treatise On Changing Beings (Fī al-Mawǧūdāt al-mutaġayyira). It is shown that this work is not only a response to book VI of John Philoponus' Contra Aristotelem, but that its real issues can only be grasped in the context of the author's metaphysical system. Although, for al-Fārābī, genuine demonstrations proceed from the cause to the caused, thus following the order of being, it will be explained how he also admits a strictly physical proof of the simple fact, independently of its cause, and that the physical demonstration of the eternity of the world pertains to this type of proof. This physical proof is specifically directed against the Kindian doctrine of creation.

This paper presents the first edition, translation and analyse of al-Māhānī’s commentary of the Book X of Euclid’s Elements (9th century, the most ancient to have reached us) and of an anonymous’ one (prior to 968, among the first algebraic commentaries). For the first time, irrational numbers are defined and classified. The algebraisation of Elements’ X-91 to 102, on the basis of al-Khwārizmī’s Algebra, shows irrational numbers as solution to algebraic quadratic equations. The algebraic calculus makes here the first steps. On this occasion, negative numbers and their calculation rules appears. Simplifications imposed by the algebraic writings are sometimes in opposition with the conclusions of propositions conceived in a purely geometrical framework, revealing a contradiction between geometrical and algebraic goals. It will be resolved by the independant way algebra will take with mathematicians belonging to the tradition of al-Karajī and al-Samaw’al from the 11th-12th centuries on.

The use of the immediate and common point of view (bādi' al-ra'y al-muštarak) is presented, in Arab philosophy, as characteristic of the rhetorical method. We will endeavour, in this article, to determine the importance, the significance and the origins of this concept in the works of Fārābī. The first part examines the concept's position in the structure of Kitāb where Fārābī, while following Rhet. I 2 (a veritable introduction to the discipline of oratory) tries to improve the structure of Aristotle's chapter around this concept, which is not in Aristotle. The concept is then defined in the second part. What is at issue is not the immediate point of view of an individual who might think of certain propositions as being universally accepted, when in fact they are not, but rather the point of view which is accepted without question by the majority. It relies on a kind of testimony (šahāda) rather than on the personal judgement of the auditor. It differs nevertheless from propositions which are really universally accepted because these can only be invalidated by an elite and not by any ordinary examination. In the third part, we will review those doctrines of Kitāb which depend on the concept of the immediate and common point of view, focusing in particular on the definition of enthymema. In the last part, we will investigate some philological and philosophical difficulties, such as the difference between rhetorical and dialectical premises, which constitute the background to the development of the concept.

Ibn Sīnā's celestial kinematics represents an important aspect of his cosmology but has up to now received little attention in the secondary literature. After a short overview of some key features of his cosmology, this article attempts to clarify the role played by the separate intellects, the celestial souls, and the celestial bodies in causing celestial motion. It challenges the common view that Ibn Sīnā adhered to the theory of ten separate intellects developed by al-Fārābī and attempts to reconstruct his astronomical-metaphysical model on the basis of his main philosophical works. In addition, the article addresses the thorny question of how motion is transmitted from the intellectual to the physical plane, and it sheds light on the place of physics, metaphysics, and astronomy in Ibn Sīnā's cosmological method.

This article lists the medical works written by Ibn Bājja, overviews those that have come down to us and studies the super-commentary of Galen's commentary to Hippocrates' Aphorisms (Sharḥ fī al-Fuṣūl). This text shows a deep influence of al-Fārābī, namely in a conception of medical experience which stems from the latter's construal of experience (tajriba) as the inductive process described by Aristotle in Posterior Analytics which brings the premises of demonstration. On this basis, Ibn Bājja advocated for a less scholastic, more empiric medicine, and his claim was echoed by Ibn Rushd. There are some similarities between Ibn Bājja's text and Ibn Rushd's K. al-Kulliyyāt fī al-ṭibb which suggest that the latter had read Sharḥ fī al-Fuṣūl. This work gives moreover some evidence that human dissection could have been performed during Ibn Bājja's time.

The notion of a “World of Images” located somewhere between the immaterial and the material world was a mainstay of eschatological speculation in late medieval Islam. As has been recognised before, the concept was launched by al-Suhrawardī (d. 1191). However, its more properly philosophical underpinnings, in particular the notion of “suspended” images – images which somehow have an objective, rather than just a mental or subjective, status – merit further clarification, which this article attempts to provide. Since the concept of “suspended forms”, while applied to eschatological matters in the last treatise of the Philosophy of Illumination, makes its first appearance in a discussion of mirror vision, I examine in some detail Avicenna's understanding of mirror vision as presented in the Shifāʾ, to which al-Suhrawardī reacts. I then undertake a detailed reconstructive analysis of two paragraphs of the Philosophy of Illumination, paying particular attention to the question of the ontological status of “suspended” or “self-subsistent” images as well as to the idea that mirrors serve, not as loci in which images inhere, but as loci at which they become manifest (singular maẓhar).

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.

Quand on compare l'Optique d'Ibn al-Haytham (Alhazen) à celle de Ptolémée, on rencontre des innovations à coup sûr capitales, et qui chacune mériterait une analyse particulière: étude expérimentale de la propagation rectiligne de la lumière, nouvelle théorie de la vision fondée sur la réception dans l'œil de rayons lumineux, recherche du lien entre l'anatomie de 1'œil et sa fonction optique, preuve expérimentale que la réfraction joue un rôle important dans la vision, et j'en passe: les dimensions d'un article de revue n'y suffiraient pas. Aussi bien mon but est-il plus global et plus synthétique. Il consiste à tenter de faire le point sur ce qu'est devenue, après Ibn al-Haytham, l'insertion de l'optique dans le système des savoirs qui lui sont connectès, en comparant cette insertion à ce qu'elle était au temps de Ptolémée, c'est-à-dire dans l'œuvre de référence (plus encore que celle d'Euclide et du pseudo-Euclide) reçae et travaillée par lui.

Textual evidence preserved in two still unpublished manuscripts strongly suggests that there once existed an alternative version of Miskawayh’s Fawz al-aṣghar, the Minor Book of Triumph. The article discusses possible explanations for why Miskawayh may have composed two recensions of his Fawz and compares structure and content of the alternative version with the edited standard version. The one passage which is contained in the alternative Fawz only is presented in Arabic with an English translation. Part of this additional material is parallel to al-Fārābī’s Iḥṣā’ al-‘ulūm, namely its division of natural sciences, and may ultimately derive from a no longer extant treatise by Paul the Persian. An appendix provides the Arabic text and English translation of a hitherto unknown fragment of al-Balkhī in which he discusses Plato’s saying that the world has a causative, but no temporal beginning.

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.

Between 9th and 11th centuries, the geometrical transformations gave to the mathematicians a method more and more fertile, leading them to modify their modes of apprehension of the geometrical figures. This article aims to highlight al-Sijzī’s contribution to this change by setting two tasks: first, to precisely understand what al-Sijzī means by transformation (he is one of the first to recognize explicitly a method in their use); and secondly, to give an account of his research on geometrical invariants, obtained by a variation of some elements of a figure. The use of transformations and the search for invariants seem to be the two faces of the same tendency, that to break with an Euclidean manner to consider the figures in a way isolated and static for better exploiting the common properties which can link them. The article is completed by the edition and the translation of a small treatise devoted to invariants.

Avicenna came to an unexpected conclusion in the treatise On Plants in al-Šifāʾ: that plants are not alive. This judgment is surprising in view of Aristotle's opinion that that which has a soul is alive. This paper shows that there is a development in Avicenna's thought on plants' life. He begins with the Aristotelian view that plants are alive inasmuch as they possess a soul, as we see in his early A Compendium on the Soul. Later, however, through his investigation of the faculties of the soul, discussed mainly in the first part of the Canon of Medicine, he is led to conclude that plants could not be said to be alive. This paper indicates the importance of considering the influence of Avicenna's medical findings on his philosophical arguments when examining the development of his thought.

The article aims to demonstrate that Avicenna's (d. 428/1037) centrality in Islamic intellectual history is not restricted to the branches of theoretical philosophy; rather, he also has had a deep and strong influence on the conception of practical philosophy until modern times. I will discuss the impact of Avicenna's view of practical philosophy by analyzing his different classifications of practical philosophy throughout his career and the factors behind his disregard for practical philosophy in his philosophical summas on the basis of his view of the relationship between philosophy and šarīʿa. To demonstrate my argument regarding Avicenna's influence on the conception of practical philosophy in Islamic tradition, I will refer to major works on the classification of sciences, and the commentaries (šurūḥ) and glosses (ḥāwāšī) on the two most important and widely circulated philosophical summas in the post-Avicennan philosophy, which are al-Abharī's (d. 663/1264) Hidāyat al-ḥikma and al-Kātibī's (d. 675/1276) Ḥikmat al-ʿayn.

In this paper, my aim is to offer some comments on the study of Mu‘tazilite kalām, framed around the study of a particular episode in the Mu‘tazilite dispute about man (‘mā huwa al-insān’) – a question with a deceptively Aristotelian cadence that is not too difficult to dispel. Within this episode, my focus is on one of the major arguments used by the late Baṣrans to hold up their side of the dispute (a side heavily indebted to Abū Hāshim’s ontological innovations), and on the relationship between the mental and the physical (or the subjective and objective) which emerges from it. The most interesting – and most surprising – aspect of this relationship is that the mental and the physical do not seem to be treated as distinct terms, thus creating the space for questions about how the two relate. The first person perspective seems to be identified with the physical body. My interest then is in the response of the reader to this surprising presentation – or rather, in a certain kind of reader response, and thus a certain kind of interpretive mode, whose value and viability it is part of my aim to help clarify.

Al-Qūhī, mathematician of the 10th century, examines critically two arguments in the 6th book of the Aristotelian Physics. This critic does not follow the method of the philosophers, with doctrinal amendments, but with a mathematical and experimental style. For understanding of this critical examination and its influence, it is necessary to situate it in the mathesis of al-Qūhī and to produce its mechanical presuppositions. This is the purpose of the author of this paper.

The importance of the Treatise on equations by Sharaf al-Dīn al-Ṭūsī (12th century) has been brought to our attention by R. Rashed (1974, 1986), who underlined the analytical aspects of this essentially algebraic work. Following Rashed, this article concentrates on one of these analytical concepts, namely the maximum of a polynomial expression f(x) of degree 3. The purpose is to clarify the techniques that led al-Ṭūsī, when computing the maximum of f(x), to systematically display algebraic equations equivalent to f(x) = 0. By demonstrating that al-Ṭūsī's essentially algebraic proofs were also based on analytical procedures, we show that the presence of these equations was not fortuitous, but resulted from a correct understanding of the maximum of f(x). The accompanying geometrical representations were primarily for illustration.

R. Rashed, Les mathématiques infinitésimales du IXe au XIe siècles, vol. IV: Méthodes géométriques, transformations ponctuelles et philosophie des mathématiques, London, al-Furqān Islamic Heritage Foundation, 2002, XIII-1064-VII p.

The earliest debate on the argument from ignorance emerged in Islamic rational theology around the fourth/tenth century, approximately seven centuries before John Locke identified it as a distinct type of argument. The most influential defences of the epistemological principle that ‘that for which there is no evidence must be negated’ are encountered in Muʿtazilī sources, particularly ʿAbd al-Jabbār and al-Malāḥimī who argue that without this principle scepticism will follow. The principle was defended on different grounds by some earlier Ashʿarīs, but was then rejected by al-Juwaynī, and was eventually classed as a fallacy by Fakhr al-Dīn al-Rāzī whose Nihāyat al-ʿuqūl contains the most definitive and comprehensive refutation of classical kalām epistemology and the first ever defence of Aristotelian logic in a kalām summa. According to the eighth/fourteenth-century historian Ibn Khaldūn, this debate provided the main impetus for the philosophical turn that Ashʿarism took during the sixth/twelfth century.