This article is about Avicenna’s account of syllogisms comprising opposite premises. We examine the applications and the truth conditions of these syllogisms. Finally, we discuss the relation between these syllogisms and the principle of non-contradiction.

This essay examines the biblical discourse on animals in Job 38-41, as interpreted by Albert the Great and Thomas Aquinas in their 13th-century biblical commentaries. In God’s first reply to Job twelve species of animals are introduced and realistically described, including accurate details of their behavior. Subsequently, chapters 40 and 41 introduce two more complex animals, Behemoth and Leviathan, in which realistic and symbolic features intertwine. This peculiarity of the book of Job – long sequences dedicated to descriptions of animals (...) – allows to investigate to what extent and how the availability of Aristotelian zoology, whose study was prescribed in the Dominican program promoted and practiced by Albert himself, became an instrument for a renewed biblical exegesis, different from the allegorical and theological moralizing hitherto prevailing in the Christian tradition of commentaries on Job. (shrink)

God is omniscient; therefore, He knows that ‘the flower in my hand is red.’ If God knows that ‘the flower in my hand is red,’ then He knows it perceptually. God does not know anything perceptually. It is clear that the set of propositions – form an inconsistent triad. This is one of four problems with which Avicenna was engaged concerning God's knowledge of particulars, which I call the problem of perceptual knowledge. In order to solve PPK and three other (...) problems, Avicenna has developed a theory concerning God’s knowledge of particulars. Secondary literature around Avicenna’s theory of God’s knowledge of particulars has mostly directed its attention to give an account of Avicenna’s positive theory rather than the problems which that theory was designed to solve. But this paper will not do the same thing as this secondary literature. In contrast, in this paper, I will concentrate on the characterization of one of the problems, i.e., PPK, because of which Avicenna has presented his positive theory of God’s knowledge of particulars. In short, this paper aims to show why Avicenna deems explaining God’s knowledge of, say, the redness of a flower, via his accepted theory of perception as problematic. In this regard, I will extract three versions of PPK based on Avicenna's philosophy and through it will shed some light on Avicenna’s theory of God’s knowledge of particulars. (shrink)

In his Kitāb al-Burhān, Avicenna discusses a theoretical framework broadly inspired by Aristotle's Posterior Analytics which brings together logic, epistemology and metaphysics. One of the central questions explored in the book is the problem of the relation between knowledge, certainty and causal explanation. Burhān 1.8, in particular, is devoted to the analysis of how certainty comes about in causal as opposed to non-causal contexts. The distinction is understood in Avicenna's system as one between cases in which the conclusion of an (...) argument is warranted only in virtue of an appropriate middle term, and cases in which there is no such intermediary because the predicative link between subject and predicate of the conclusion is immediate. In this context, Avicenna makes use of the case of relative terms to clarify certain crucial aspects of his theory. The paper explores this discussion and shows how Avicenna's account of the relatively marginal role of relatives in the context of demonstration depends on insights that are central to his metaphysics and epistemology. (shrink)

There is a disagreement among contemporary commentators about Avicena's view of the theoretical intellect in "Kitāb alnafs". Is its activity performed by an internal sense helped by the intellect, or is it a activity proper of the intellect independently of material forms? Some passages of V.5 and V.6 suggest that both elements are necessary to the knowledge: unifying the multiplicity and multiplying the unity; in others words, it is not enough that the intellect conceptualizes the minor and major terms of (...) the syllogism, it also needs to intuit the middle term. (shrink)

A questão "se uma elocução perde seu significado com a destruição das coisas "surge como uma questão sobre o valor-verdade de declarações com um termo vazio como sujeito, a saber, como um subproblema do sofisma "Se 'omnis homo de necessitate est animal' é verdade quando não há homem algum ". Neste trabalho, trarei as discussões conforme elas se apresentam em "De signis" IV.2 de Roger Bacon, em "Quaestiones logicales", q. 2–3 de Peter John Olivi, no OHNEA de Boethius of Dacia, (...) e no OHNEA de Anonymus Alani. Tais textos nos apresentam quatro modos diversos de nos relacionarmos com a questão sobre significação para OHNEA e, assim, com quatro posições diferentes sobre a relação entre significação e referência vazia. Usarei Anonymus Alani como o fio conductor de minha análise, inserindo outras posições onde tal se fizer relevante. The question 'whether an utterance loses its signification with the destruction of things ' is raised as a question about the truth-value of assertions with an empty term as a subject, namely as a sub-problem of the sophism 'Whether "omnis homo de necessitate est animal" is true when no man exists '. In this paper, I shall introduce the discussions as they are present in Roger Bacon's "De signis" IV.2, Peter John Olivi's "Quaestiones logicales", q. 2–3, Boethius of Dacia's OHNEA, and Anonymus Alani's OHNEA. These texts present us with four different ways of relating the question about signification to OHNEA, and therefore with four different positions regarding the relation between signification and empty reference. I shall use Anonymus Alani as the guiding thread of my analysis, inserting other positions where it is relevant. (shrink)

Averroes is well-known for his controversial thesis that there is only one separate intellect for all humankind. This article provides a detailed analysis of Averroes’s Unity Argument from his Long Commentary on De Anima, which argues from unified intelligible concepts to a single transcendent intellect. I set out the Unity Argument in its textual and philosophical context, explain exactly how the argument works on a new interpretation of its infinite regress, and offer some brief suggestions as to how it might (...) be further evaluated in light of alternative ancient and medieval theories. Ultimately, I demonstrate that the Unity Argument is Averroes’s most important philosophical argument for his distinctive view of intellect. (shrink)

Avicenna introduces the primary propositions as the most fundamental principles of knowledge. However, as far as we are aware, Avicenna’s primaries have not yet been independently studied. Nor do Avicenna scholars agree on how to characterize them in the language of contemporary philosophy. It is well-known that the primaries are indemonstrable; nonetheless, it is not clear what the genealogy of the primaries is, how, epistemologically speaking, they can be distinguished from other principles, what their phenomenology is, what the cause of (...) the assent to them is, how to explain the relationship between the ‘innate [nature] of the intellect’ and the primaries and, finally, back to their indemonstrability, in what sense they are ‘indemonstrable’. We will try to fill this gap. As a corollary, we will explain why Gutas’s view [Gutas, Dimitri.... (shrink)

In Modal Logic as Metaphysics, Timothy Williamson claims that the possibilism-actualism (P-A) distinction is badly muddled. In its place, he introduces a necessitism-contingentism (N-C) distinction that he claims is free of the confusions that purportedly plague the P-A distinction. In this paper I argue first that the P-A distinction, properly understood, is historically well-grounded and entirely coherent. I then look at the two arguments Williamson levels at the P-A distinction and find them wanting and show, moreover, that, when the N-C (...) distinction is broadened (as per Williamson himself) so as to enable necessitists to fend off contingentist objections, the P-A distinction can be faithfully reconstructed in terms of the N-C distinction. However, Williamson’s critique does point to a genuine shortcoming in the common formulation of the P-A distinction. I propose a new definition of the distinction in terms of essential properties that avoids this shortcoming. (shrink)

This chapter on creation and eternity in medieval philosophy focuses on arguments for the world's age drawn from the nature of time. To this end, there are four main sections. The first covers proofs for the eternity of the world taken from the nature of time, with an emphasis on Aristotle's original argument for that thesis and then Avicenna's modal version of the proof. The second deals with rejoinders, based upon non‐Aristotelian conceptions of time, to proofs for the eternity of (...) the world with a focus on Augustine's idealist conception of time. The third section takes up positive arguments for the temporal finitude of the cosmos and the difficulties surrounding the idea of infinite past time. The final section canvasses the “agnostic position” of Ibn Tufayl, Moses Maimonides, and Thomas Aquinas concerning the question of the cosmos's age. (shrink)

Elucidating a metaphysics of medicine is vital for framing a coherent medical ethics. In this paper, I examine the historical case of Avicenna, the eleventh century physician-philosopher. Avicenna radicalizes the dissective power of reason using a logicized Aristotelian metaphysics to clarify concepts at the metaphysical level, which I call his anatomy of being. One of the practical consequences of Avicenna’s metaphysics is a dehumanizing eschatology of death. I outline the main elements of Avicenna’s thought that constitute his anatomy of being. (...) Through an examination of his logic, metaphysics, and psychology, I show how Avicenna develops a dissective logic. I conclude that one’s epistemology, as a method of knowing, entails a metaphysics, and, in turn, results in an ethical stance to the object of knowledge. For Avicenna, mental dissective logic applied to humans results in dehumanization, thereby destroying the humanistic impulse of medicine. (shrink)

Avicenna’s logical theory of negative judgement can be seen as a systematic development of the insights Aristotle had laid out in the De interpretatione. However, in order to grasp the full extent of his theory one must extend the examination from the logical works to the metaphysical and psychological bases of negative judgement. Avicenna himself often refrains from the explicit treatment of the connections between logic and metaphysics or psychology, or treats them in a rather oblique fashion. Time and again (...) he is satisfied with noting that this or that question is not proper for a logician and should be dealt with in metaphysics or psychology—without bothering to refer his reader to the exact loci. The following is an attempt at a reconstruction of Avicenna’s theory of negative judgement in such a broad fashion. I will begin with his analysis of negative judgement as resulting from an operation of ‘removing’ the predicate term from the subject term. On this basis, I will move on to discuss how he conceives of the relation between negative judgements and affirmative judgements that contain privative or metathetic terms as well as the question of whether negative judgements can be reduced to affirmative ones. Having thus laid out his logical theory of negation, I move on to discuss the underlying metaphysics by looking at the relation between existence and non-existence, and existence and privation. Finally, I will address Avicenna’s scattered psychological remarks on how we can conceive of what does not exist. (shrink)

Logic, an old discipline with a long history, is a product of the nature of thinking that is based on mental thought, which is distinguished from other creatures by human nature. Logical thought and various forms of rational inference, seen in all the geographical regions of the world before attaining a systematic structure, have directed to human life and its scientific products. A systematic structure is taken back to Parmenides, lived in ancient Greek thought. The logic developed from various directions (...) was given a proper shape by Aristotle nearly two thousand years ago and has been in continuous development and transformation in the direction of human mind and its needs. Today, in addition to Aristotelian logic, which is two most valuable structures, many valued logics have emerged.. Quite different logic conception emerges from classical logic, however, which is considered as a beginning for philosophical thought and is one of the important factors in reaching the goal of the philosophical effort. But the presence of classical logic continues in the areas of religious, classical philosophy and social sciences. In this frame, the value of classical logic from past histories requires the position that it deserves. Especially, in the area of logic as well as the problems faced in logic education, more effective planning is required especially in the higher education level. This article will briefly discuss the structure of logic and its various interpretations. It will also point out the importance of logic and will draw attention to the problems in the Theology Faculties. A few suggestions that we want to discuss in this framework will also be put forward. (shrink)

Avicenna's proof for the existence of God (the Necessary Existent) in the Metaphysics of the Salvation relies on the claim that every possible existent shares a common cause. I argue that Avicenna has good reason to hold this claim given that he thinks that (1) every essentially ordered causal series originates in a first, common cause and that (2) every possible existent belongs to an essentially ordered series. Showing Avicenna's commitment to 1 and 2 allows me to respond to Herbert (...) Davidson's and Richard Swinburne's claim that Avicenna's proof for the Necessary Existent is incomplete and fallacious -/- . (shrink)

Light is a discursive tool that Sufis have drawn upon over the centuries in order to elucidate systems of thought and practice. In medieval Islamic thought, light was closely associated with the soul as well as conceptions of sight and the eye. It also occupied an important place in cosmology. By the twelfth- and thirteenth-centuries, Sufis began to consider notions of light more systematically, creating close correspondences between vision, cosmology, and anthropology within Sufi thought. This coincided with the increased production (...) of complex diagrams in Sufi texts. This article shows that these developments were interrelated. By analyzing Shams al-Dīn al-Daylamī’s diagrams alongside his theories of light with respect to the nature of the soul and body, it demonstrates that the theory of the soul as light played an important part in shaping Sufi thought, practice, and visual culture. (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 chapter discusses the first part of Aristotle's Posterior Analytics A-33, 88b30-89a10. I claim that Aristotle is not concerned with an epistemological distinction between knowledge and belief in general. He is rather making a contrast between scientific knowledge (which is equivalent to explanation by the primarily appropriate cause) and some explanatory beliefs that falls short of capturing the primarily appropriate cause.

This thesis is concerned with answering the question, what is the central argument of Avicenna’s Metaphysics of the Healing that brings its opening ontological approach to the subject of first philosophy to its ultimate theological goal and conclusion? This dissertation contends that it is the function of the fundamental scientific first principles of metaphysics, and in particular the fundamental primary notion necessary, to provide the intelligible link that Avicenna employs to demonstrate the existence and true-nature of the divine necessary existence (...) in itself on the basis of his doctrine of being. This conclusion is pursued through a systematic and cumulative line of inquiry that begins in Part I with Avicenna’s logical–cum–epistemological doctrine of conceptualization and assent, the heuristic order of the basic scientific questions, and his theory of a demonstrative science. The thesis then moves from the wider concentric circles concerned with logical matters into a series of narrowing concentric circles pertaining to the scientific order of the MH. Part II presents a close analysis of the Metaphysics of the Healing’s novel reception and reorganization of Aristotelian metaphysics according to Avicenna’s theory of demonstrative science, which consists in a subject, scientific first principles, and objects of inquiry that includes the species, proper accidents, and the science’s ultimate goal which is the aitiological–cum–theological inquiry into the causes of being. Part III transitions into a still narrower set of concentric circles that provide a detailed explication of the formal and material aspects of the scientific first principles of the Metaphysics of the Healing. Finally, the main argument of the thesis reaches the central point and question of the dissertation in Part IV, which establishes the fundamentality of the primary notion the necessary in the ontology, aitiology, and theology of the Avicenna’s Metaphysics of the Healing. Part IV concludes that the principal function of the fundamental primary notion the necessary is to provide the intelligible link that connects Avicenna’s doctrine of being with the divine necessary existence in itself. (shrink)

A discussão nos livros dos Tópicos giram em torno dos debates dialéticos e seus elementos. Aristóteles discorre sobre os gêneros, as propriedades e os chamados acidentes e suas relações predicativas em categorias. Interessa-nos, sobretudo, compreender o papel desempenhado pela Definição e qual sua relação com os demais instrumentos para a dialética.