This paper is devoted to Ibn Sinān's treatise on analysis and synthesis. Ibn Sinān's text deals with two distinct, though closely related, subjects. First he considers the classification of problems, founded on the logical criteria which are the number and degree of indetermination of the solutions and (though in a less relevant way) the number of hypotheses and their possible independence. This classification does not replace the Hellenistic one, which remains relevant insofar as it purports to solve geometrical problems, but complements it and has a different frame of reference, applying principally to algebra, that new born science. Ibn Sinān's classification will be taken up and used by algebraists. Secondly, the text presents a new way of setting out analysis and synthesis, so that they become exactly reciprocal. This leads Ibn Sinān to bestow more importance on the role played by analysis in the course of the proof, the only role left to synthesis being to check that all implications involved in the course of analysis are in fact equivalences. This method will prove to be productive in algebra too, so much so that some algebraists will explicitly identify algebra with analysis.

Abraham ibn Ezra's (ca 1089-ca 1167) scientific corpus represented an exceptional case: instead of the common Latin model embodied by the scholar coming from the Christian North to the Iberian Peninsula to initiate a translation enterprise, we have in Ibn Ezra the contrary case of an intellectual imbued with the Arabic culture, who abandons al-Andalus, roams around the Christian countries and delivers in his wandering through Italy, France and England, the scientific and cultural cargo that he amassed during his youth in al-Andalus. The main purpose of this article is to provide a picture of Ibn Ezra's scientific corpus as comprehensive and detailed as possible given the present state of research. The paper will fall into two main parts: (a) Ibn Ezra's scientific work will be broken up into three main genres: (1) Mathematics, Astronomy, Scientific Instruments and Tools; (2) The astrological encyclopaedia; (3) Translations from Arabic into Hebrew. (b) In the second part, Ibn Ezra's scientific corpus will be reassembled as a whole in order to provide a global characterization, trying to point out its general organization and shape, and to indicate its main aims and special traits revealing Ibn Ezra personal contribution.

Man's individual responsibility is a very central notion in Muslim theology. Rational foundations for moral responsibility presuppose, however, that man has in some way control over his actions. It was therefore of central concern to theologians to formulate theories of action that were coherent enough to account for human self-determination. This article examines al-Bāqillānī's reflections on human acts and attempts to contextualise his thought within the discussions of his time. I will briefly review the Muʿtazilites’ theory of freedom of action, against which the Ašʿarite school developed its own position. I will then outline the fundamentals of the opposing standpoint adopted by Abū al-Ḥasan al-Ašʿarī, who proposed to base human self-determination on voluntariness. Finally, I will discuss how al-Bāqillānī drew on and further developed al-Ašʿarī's ideas. Based on the extant volumes of al-Bāqillānī's Hidāyat al-mustaršidīn, I argue that he attempts to coherently organise the school's understanding of the famous theory of “acquisition” (kasb) by affirming two fundamental principles: a) that human acts are created by God and b) that there is nevertheless a real correlation between man and his “acquired” acts.

From the second half of the 10th century, mathematicians developed a new chapter in the geometry of conic sections, dealing with the theory and practice of their continuous drawing. In this article, we propose to sketch the history of this chapter in the writings of al-Qūhī and al-Sijzī. A hitherto unknown treatise by al-Sijzī - established, translated, and commented - has enabled us better to situate and understand the themes of this new research, and how it eventually approached the problem of the classification of curves in previously unknown terms.

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.

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.

Ṯābit b. Qurra is especially known as a mathematician, but his work in astronomy is also important. This article reviews his eight surviving astronomical treatises, as well as relevant fragments of his lost works cited by later authors in Arabic and Latin. We conclude that, as an active participant in the scientific movement of 9th-century Baghdad, Ṯābit played a crucial role in the establishment of astronomy as an exact science. The argument is based on an assessment of his contribution in three areas: the relationship between observation and theory, the “mathematization” of astronomy, and the relationship between “mathematical” astronomy and “physical” astronomy.

This is the first paper in a series in which we provide critical editions of four texts written between the eleventh and the thirteenth century concerning Proposition III.5 of Menelaus' Spherics. The first paper contains introductory material on the work of Ibn ʿIrāq on spherical geometry and a critical edition of his two texts on the rectification of Proposition III.5, together with translations and historical and mathematical commentaries. The second paper contains critical editions of the texts by Naṣīr al-Dīn al-Ṭūsī and Ibn Abī Jarrāda on the same subject, again with translations and historical and mathematical commentaries.

This paper provides an analysis and translation of a previously edited, but otherwise unstudied work by Miskawayh (d. 1030) entitled On Pleasures and Pains (Fī al-Laḏḏāt wa-al-ālām). After a brief orientation regarding the Aristotelian account of pleasure in the Nicomachean Ethics, which is Miskawayh's main source, the theory of pleasure set out in On Pleasures and Pains is compared to the discussion of pleasure in Miskawayh's better known Refinement of Character (Tahḏīb al-aḫlāq). Despite considerable harmony between the two texts, their treatments of pleasure differ in that the Refinement accepts, whereas On Pleasures and Pains rejects, the “restoration” theory of pleasure of Plato's Timaeus.

Where Averroes' commentaries on Aristotle can be dated, the Middle Commentary on a given work can be seen to predate the Long Commentary. As an accompaniment to his fine edition of Averroes' Middle Commentary onthe De anima, A. Ivry has maintained that in this instance matters are reversed and the Middle Commentary on the De anima is “an abridged and revised version” of the Long Commentary on the same work. Ivry develops his thesis most fully in Arabic Sciences and Philosophy 5. There he argues that two passages in the Middle Commentary on the De anima refer to the Long Commentary by name, that a third passage alludes to the Long Commentary, and that in other passages the Middle and Long Commentaries use similar phraseology and the former can be seen to have abridged the latter. The present article replies as follows: The pair of passages in the Middle Commentary which Ivry reads as referring explicitly to the Long Commentary can plausibly be read as cross-references within the Middle Commentary itself. The passage that he takes as alluding to the Long Commentary does not in fact allude to that work, but is an unambiguous reference to a later section of the Middle Commentary. And there is no justification for regarding the passages in the Middle Commentary cited by Ivry which use phraseology similar to that of the Long Commentary as borrowings from the latter. In the course of his arguments, Ivry refers to Averroes' position on the nature of the human material intellect, the issue that gave Averroes the most trouble in his commentaries on Aristotle's De anima and that has most intrigued students of Averroes ever since. The present article points out that on the subject of the human material intellect, neither the Middle nor the Long Commentary on the De anima borrows from the other, for the conceptions of the material intellect which they espouse are different and incompatible.

Though much has been written of late about Averroes and his philosophy, little attention has been paid to his political teaching. Generally speaking, his works can be divided into two categories: (a) commentaries on Aristotle and other important thinkers and (b) occasional treatises written to resolve particular questions. The subject of this essay, his political teaching, is stated most directly in the first classification of writings – especially in his commentaries on Aristotle's Rhetoric and Plato's Republic. Even though the second kind of writings helps to nuance some of his broader themes — especially the two treatises having to do with the relationship between philosophy anddivine law, namely, the Decisive Treatise and its sequel Kashf an manāhij al-adilla — considerations of space preclude an analysis of them here. Our examination of the first two writings will focus primarily on what Averroes has to say about the different kinds of political regimes and, above all, the best regime, for his discussion of it leads him to reflect more generally on other major political questions.

After having reformulated optics, Ibn al-Haytham conceived of an analogous project for astronomy. This has just been revealed by an important book by the mathematician which has never been studied until now. Ibn al-Haytham's reform consists in excluding all cosmology, and in developing a systematic study of a celestial kinematics that has been completely geometrized. In turn, the realization of such a reform demanded innovative research in infinitesimal geometry. In this article, an attempt is made to present this new geometry, as well as the mathematical means invented to elaborate it.

Ibn Sarābiyūn is one of the last exponents of classical Syriac medical writing, and one of the most influential authors for the development of medical theory and practice in late ninth-century Baghdad in particular, and for the Arabic medical tradition in general. During the last thirty years, three important studies have been published regarding the life and work of Ibn Sarābiyūn, each of which dealing with a different aspect of the transmission of this important author’s œuvre. Likewise, during the last twenty-five years, a number of texts associated with Ibn Sarābiyūn's works have been edited, allowing us today to shed new light on the relation between the original Syriac and the numerous translations into Arabic, Latin and Hebrew. Furthermore, through analysing and comparing a number of manuscripts containing different parts of Ibn Sarābiyūn's work which have not hitherto been considered together, progress can be made towards answering the question how Ibn Sarābiyūn was translated and used during the medieval period.

The present article aims to show that the treatise On the Harmonization of the Opinions of the Two Sages the Divine Plato and Aristotle cannot have been written by al-Fārābī. It considers to this end four crucial issues treated in this work, concerning (1) divine Providence and the particulars, (2) Platonic Ideas and the divine Intellect, (3) creation ex nihilo and (4) the divine attribute of ‘will’. It establishes in each case that the thesis defended by the author is contrary to al-Fārābī’s doctrine and akin to that of Yaḥyā ibn ‘Adī. This twofold result prompts us to suggest that the author should be associated with Ibn ‘Adī and his milieu; it also suggests a new periodization of 10th century Arabic philosophy. Rather than imagining a Kindian phase followed by a ‘‘school of Baghdad’’ extending from al-Fārābī’s masters to the age of Avicenna, we should postulate that some of al-Fārābī’s followers returned to al-Kindī in the field of cosmology, for theological reasons.

The Hebrew text On the Heavens and the World, ascribed to Ibn Sīnā, is an interesting and intriguing composition. It dates from the 13th century and was quite influential. It is not a translation of any text of Ibn Sīnā known to us, but is related to the (pseudo-Avicennian) Latin De celo et mundo, which appears in the 1508 Venice edition of translations of Ibn Sīnā. The Latin and Hebrew texts differ widely and the relation between them is far from being clear. Both are in sixteen chapters, the titles of the chapters are the same, but the texts are only roughly similar. The Hebrew text often offers short, incomplete summaries of the Latin arguments. On the other hand it includes many passages which have no parallel in the Latin. There are two possible explanations of the perplexing relationship between the two texts: either that there was more than one version of the Latin (or of the original Arabic) text, or that the translator, Shlomo ben Moshe of Laguiri wrote a kind of paraphrase. The paper shows that the second explanation is correct and offers a preliminary study of the sources and the aims of the Hebrew text.

How do the heavenly bodies physically affect the sublunary world? On this topic, the few fragmentary statements by Aristotle were refined and expanded by his Greek commentator Alexander of Aphrodisias. In the Kindī-circle, particular attention was paid to Alexander's treatises on this very topic. They were not simply translated but were rather reworked in terms of an astrological interpretation. Typically, such reworking was attributed directly to Aristotle by the addition of a number of references and pseudo-references to Aristotle's genuine and spurious works. The article demonstrates this phenomenon, and examines the circular relationship between the Kindī-circle adaptations of Alexander and al-Kindī's own works. The Kindī-circle's Alexander was closely followed by al-Kindī on certain points, while al-Kindī himself exerted a reciprocal influence on the Arabic Alexander, who was largely the product of his own group of translators. The appendix contains English translations from Arabic of two adapted Alexander's treatises.

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.

R. Rashed, Géométrie et dioptrique au Xe siècle, Ibn Sahl, al-Qūhī et Ibn al-Haytham (Paris, Les Belles Lettres, 1993); OEuvres philosophiques et scientifiques d'al Kindī, vol. I: L'Optique et la catoptrique (Leiden, E.J. Brill, 1997); Les Catoptriciens grecs (Paris, Les Belles Lettres, 2000).

The classic Arabic bibliographies ascribe to al-Fārābī a treatise entitled Fī māhiyyat al-nafs (“On the Essence of the Soul”), of which no Arabic manuscript is known to exist. There is however a Hebrew text, translated from the Arabic by Zeraḥiah ben She'altiel Ḥen of Rome in 1284, which is ascribed to al-Fārābī in all the manuscripts and which carries the title Ma'amar be-mahut ha-nefesh (“Treatise on the Essence of the Soul”). Since Steinschneider, this text is taken to be the translation of al-Fārābī's treatise lost in the original. In this paper I argue that the Ma'amar be-mahut ha-nefesh is not by al-Fārābī: it is in vain that one looks in it for ideas characteristic to the Second Master, while the ideas expressed therein are incompatible with those of al-Fārābī. I offer a study of Ma'amar be-mahut ha-nefesh, followed by an annotated translation into French. This is a “popular” Neoplatonic text, whose ideas are mostly very ordinary, but in part uncommon. It notably explains the emergence of forms in matter by positing the existence of a pneuma that by circulating around the body “brings forth” the vegetative and animal souls. The author also draws on an unusual notion called hemshel in Hebrew (a term probably translating the Arabic mithāl, rendered as exemplum in Latin): the exemplum is said to become visible as a result of the pneuma's circular motion. The paper is followed by a short Note by Rémi Brague looking into the sources of the treatise. Brague concludes that the text cannot be assigned to any specific tradition.

Since Ibn Mattawayh and Mānkdīm up until George Hourani and Marie Bernand, there is an unstoppable interest among scholars towards ʿAbd al-Jabbār theory of knowledge. This interest has increased after the publication of the works of the late Muʿtazilites such as Kitāb al-Muʿtamad fī Uṣūl al-Dīn of Ibn al-Malāḥimī and Kitāb Taṣaffuḥ al-Adilla of his teacher Abū al-Ḥusayn al-Baṣrī. This article seeks to examine ʿAbd al-Jabbār's theory of immediate knowledge based on his Mughnī and other sources from his students and the late Muʿtazilites. I will also examine the implication of ʿAbd al-Jabbār's view on immediate knowledge on his theological arguments. This article is divided into two divisions; firstly, I will study the definition of immediate knowledge according to ʿAbd al-Jabbār and the responses from his successors. Secondly, I will analyze his view on the types of immediate knowledge that closely related to his theological arguments. From this point of view I will indicate that the disagreement about the content of immediate knowledge will lead to the dispute on the theological arguments among Muslim theologians (mutakallimūn).