Avicenna (d. 1037) and Tūsī (d. 1274) have different doctrines on the contradiction and conversion of the absolute proposition. Following Avicenna's presentation of the doctrine in Pointers and reminders, and comparing it with what is given in Tūsī's commentary, allow us to pinpoint a major reason why Avicenna and Tūsī have different treatments of the modal syllogistic. Further comparison shows that the syllogistic system Rescher described in his research on Arabic logic more nearly fits Tūsī than Avicenna. This in turn (...) has consequences for analysing Avicenna's logic, and for writing the history of a fascinating period of change and diversity in the discipline in the medieval Islamic world. (shrink)

This paper examines al-Fārābī's logical thought within its Arabico-Islamic historical background and attempts to conceptualize what this background contributes to his logic. After a brief exposition of al-Fārābī's main problems and goals, I shall attempt to reformulate the formal structure of Arabic linguistics (AL) in terms of the ontological and formal characteristics that Arabic logic is built upon. Having discussed the competence of al-Fārābī in the history of AL, I will further propose three interrelated theses about al-Fārābī's logic, in terms (...) of which I will attempt to redefine it: the logico-linguistic conception, the project of logicization, and nuclear logic. The final question that will arise is how Aristotle's logic could be built upon AL, which has a nature contrary to logic. The present paper also contributes to examining our traditional research habits in Arabic studies. (shrink)

In this article, the author studies some central concepts in Avicenna's and sī's modal logics as presented in Avicenna's Al-Ish r t wa'l Tan īh t ( Pointers and Reminders ) and in sī's commentary. In this work, Avicenna introduces some remarkable distinctions in order to interpret Aristotle's modal syllogistic in the Prior Analytics . The author outlines a new interpretation of absolute sentences as temporally indefinite sentences and argues on the basis of this that Avicenna seems to subscribe to (...) the Principle of Plenitude. He also shows that he has no valid proof of the modal conversion rules and that he uses some rather ad hoc distinctions to show that Aristotle's modal syllogistic is correct. The author also notes some interesting differences between Avicenna's and sī's approaches to modal logic. (shrink)

Al-Fārābī's lost commentary on Aristotle's Ethica Nicomachea is without doubt one of the most sorely missed lost works of the Islamic falāsifa. In part, this is because the commentary was in some respects a scandal, and scholars accordingly believe it may hold the key to resolving present-day disagreements on how to interpret al-Fārābī's views as expressed in his independent treatises. Perhaps al-Fārābī's most shocking or scandalous statement is that preserved by the Hispano-Muslim philosophers Ibn Bājja, Ibn Ṭufayl, and Ibn Rushd. (...) According to them al-Fārābī says in his commentary on Aristotle's Ethica Nicomachea that happiness is to be achieved only in this life, not in the afterlife; that there is no happiness but political happiness; and that union with the active intellect – generally considered the highest goal of human existence by the philosophers – is impossible. This paper addresses the following questions: What exactly is the debate about? Why is the question of immortality or conjunction related to Aristotle's Ethica Nicomachea? And why was it so controversial to say, in the context of the Ethica Nicomachea, that there is no happiness but political happiness? Although the bulk of al-Fārābī's commentary is still lost, I have discovered two quotations of it in Hebrew manuscripts. As I will argue in this paper, these newly-discovered quotations – which are included with an English translation in the appendix – can shed light on the mysteries concerning al-Fārābī's commentary. Résumé Le commentaire perdu d'al-Fārābī à l’ Ethique à Nicomaque d'Aristote est sans conteste, parmi les ouvrages perdus de philosophes islamiques, l'un de ceux dont on regrette le plus l'absence. Cela s'explique notamment par le caractère à certains égards scandaleux de ce commentaire, dont les spécialistes attendent dès lors qu'il recèle la clé pour résoudre les désaccords actuels quant à l'interprétation à donner aux idées formulées par cet auteur dans ses traités personnels. La thèse peut-être la plus choquante ou scandaleuse d'al-Fārābī est celle qui est préservée par les philosophes hispano-islamiques Ibn Bājja, Ibn Ṭufayl et Ibn Rushd: selon eux, il affirme, dans son commentaire à l’ Ethique à Nicomaque, que le bonheur ne saurait se réaliser qu'en cette vie et non dans l'au-delà, qu'il n'y a pas de bonheur autre que le bonheur politique, et que l'union à l'intellect agent – généralement tenue par les philosophes pour être la fin suprême de l'existence humaine – est impossible. Cet article traite les questions suivantes: quel est exactement l'enjeu de ce débat? Pourquoi les questions de l'immortalité et de la conjonction sont-elles liées à l’ Ethique à Nicomaque? Et en quoi était-il si problématique d'affirmer, en référence à cette œuvre, qu'il n'y a pas de bonheur autre que le bonheur politique? Même si le corps du commentaire d'al-Fārābī est encore perdu, j'en ai découvert deux citations dans des manuscrits hébreux. Comme je le soutiens ici, ces citations récemment découvertes – données dans l'appendice avec leur traduction anglaise – font un peu de lumière sur les mystères du commentaire d'al-Fārābī. (shrink)

I argue that, in the Prior Analytics, higher and above the well-known ‘reduction through impossibility’ of figures, Aristotle is resorting to a general procedure of demonstrating through impossibility in various contexts. This is shown from the analysis of the role of adunaton in conversions of premises and other demonstrations where modal or truth-value consistency is indirectly shown to be valid through impossibility. Following the meaning of impossible as ‘non-existent’, the system is also completed by rejecting any invalid combinations of terms (...) in deductions or conversions. The notion of impossibility reaches the core of Aristotle's system in the Prior Analytics. On the one hand, the use of adunaton shows that he is following one of the two requisites for demonstrative science formulated in the Posterior Analytics, i.e. to demonstrate that it is impossible for things to be otherwise than stated. On the other hand, that demonstrations through impossibility are rooted in the notion of contradiction supp.. (shrink)

When questioning whether political deception can be ethically warranted, two competing intuitions jump to the fore. First, political deception is a fact of human life, used in the realpolitik of governance. Second, the ethical warrant of truth asserts itself as inexorably and indefatigably preferable to falsehood. Unfortunately, a cursory examination of the history of philosophy reveals a paucity of models to marry these basic intuitions. Some thinkers (e.g., Augustine, Aquinas, Grotius, Kant, Mill, and Rawls) privilege the truth by neglecting the (...) realpolitik, i.e., the truth is inviolate. Others (e.g., Machiavelli, Bentham, and the often infamous caché of 20th century dictators) focus upon the realpolitik to the exclusion of the primacy of the truth. A third group of critical thinkers (e.g., Arendt and Bok) examine the topic but offer no positive, systematic treatment of deception. Lacking are theories which simultaneously recognize that political untruth is often necessary, but that untruth is only justified when a) truth is politically impossible, b) the necessity of untruth is demonstrable, and c) the truth can be replaced with a minimally injurious untruth. Plato offers one such account in the Republic, arguing that deceit must be applied medicinally to the city. However, his account is problematic in detail. One of Plato’s inheritors, the 10th century thinker al-Fārābī, advanced Plato’s theoretical account, arguing that political governance requires restrained political deception. This deception, the expression of philosophical truths through the symbols of religion, meets the criteria mentioned above, being necessary, demonstrably necessary, and minimally injurious. But while al-Fārābī provides a valuable model for what justified political deception could look like, the lengths to which he must go in order to create a viable model for political deception reveals the untenability of the notion of justified political deception writ large. One must orchestrate an entire cosmos around the notion, notably a cosmos that does not match our own. One must adopt very specific conceptions of human nature, association, and happiness, as well as a particular metaphysics and epistemology. For, while al-Fārābī shows that political deception can be justifiable, he also reveals its unjustifiability outside an idealized setting. (shrink)

This dissertation offers a new and comprehensive analysis of Abū Naṣr al-Fārābī's cosmology by focusing on various important issues that have been largely neglected by the modern scholarship. It provides an examination of the physical, metaphysical, and astronomical aspects of al-Fārābī's cosmology by adopting a multidisciplinary approach that takes into account the history of philosophy and the history of astronomy. Accordingly, my dissertation explores how al-Fārābī attempted to reconcile features of Ptolemaic astronomy with Aristotelian and Neoplatonic theories, an endeavor which (...) resulted in the formulation of innovative cosmological ideas. Chapters I and II provide background information on al-Fārābī's activity as a commentator and his relation to the Greek commentatorial tradition and assess the relevant primary sources. In addition, they examine al-Fārābī's approach to cosmology and his scientific method in terms of both the Ptolemaic astronomical tradition and the Aristotelian corpus. Chapter III addresses problems related to the structure of al-Fārābī's cosmology, especially the origin of his ennadic cosmological model and his spherology. Particular attention is devoted to the question of how Aristotle's unmoved movers and Ptolemy's astronomical theories are reconciled. Chapters IV, V, and VI analyze the place of celestial matter, intellect, and motion respectively in al-Fārābī's cosmology and attempt to redefine the second teacher's relation to the various trends of Greek philosophy. The study stresses al-Fārābī's connection with the Neoplatonic and Peripatetic currents, particularly with thinkers such as Alexander of Aphrod. (shrink)

Al-Ghazālı̄ famously claims in the Incoherence of the Philosophers that al-Fārābī and Avicenna are unbelievers because they hold philosophical positions that conflict with Islam. What is less well-known, however, is that Averroës claims in the Decisive Treatise that al-Fārābī and Avicenna are not unbelievers; rather, al-Ghazālı̄ is the true unbeliever for writing the Incoherence of the Philosophers. In this paper, my aim is to present a sustained reconstruction of Averroës’ legal and philosophical argument for why al-Ghazālı̄ is an unbeliever. The (...) crux of Averroës’ argument is that al-Ghazālı̄ has expressed false allegorical interpretations of scripture to unqualified persons, which has led them into unbelief. By being causally responsible for other people’s unbelief, al-Ghazālı̄ is an unbeliever as well. (shrink)