• Start
  • Previous
  • 15 /
  • Next
  • End
  •  
  • Download HTML
  • Download Word
  • Download PDF
  • visits: 3294 / Download: 2173
Size Size Size
Logic in the Islamic Legacy: A General Overview

Logic in the Islamic Legacy: A General Overview

Author:
Publisher: www.logic.sysu.edu
English

This book is corrected and edited by Al-Hassanain (p) Institue for Islamic Heritage and Thought

Logic in the Islamic Legacy: A General Overview

Prof Dr. Aref Al Attari

Faculty of Education Yarmouk University -Jordan

draref@hotmail.com, arefatar@yahoo.com

Lecture Delivered at the Institute of Logic and Cognition

San-Yat Sun University Guangzhou- P.R. of China

March 2011

A text by Avicenna (Ibn Sina)

Table of Contents

Logic: A brief overview. 5

The Beginnings 6

The Aristotelian Expositors 8

Al-farabi 8

Averroes (Ibn Rushd) and the End of Aristotelianism. 10

Dissention from Aristotelian Legacy. 12

The Avicennan Tradition of the Twelfth Century. 12

Tûsî and the Neo-Avicennan Response 12

Revisionist Avicennan Logicians 13

Ghazâlî and Logic 14

lbn Taymiyya 17

The Decline 19

Domains of Logic 20

The Subject Matter of Logic 20

Secondary Intelligibles 21

Conceptions and Assents 22

Logic and Language 25

Concluding Remarks 28

In this lecture I traverse the following:

-A prelude with reference to Greek logic and the early encounter of Muslims with the Greek logic

-The Aristotelian Proponents: Al Farabi and Averoes (Ibn Rushd)

-The Middle path: Al Gazali

-The Post Aristotelianism: Avicena (Ibn Sina)

-The Anti Greek Logic: Ibn Taimyyah

-Logic-related issues

-Concluding Remarks

Logic: A brief overview

Logic is the discipline of valid reasoning, inference and demonstration. While many cultures have employed systems of reasoning, and logical methods are evident in all human thought, logic descending from the Greek tradition, particularly Aristotelian logic, impacted more on and was further developed by Islamic logicians from the 8th till 14th centuries.

"Mantiq " is the Arabic equivalent of "logic". It points to the practice of defending the tenets of Islam through rational argument.

The Beginnings

The study ofmantiq was initially part of the foreign disciplines, and only in the twelfth century was it was accepted as an essential preliminary to a Muslim education. The other essential elements were the Islamic disciplines which prepared a scholar to read the Koran and Traditions, and to extract from them theological and legal doctrines. One such discipline was the etiquette of debate in which pragmatic arrangements stipulated for a debate about legal principles were extended to serve as rules for any kind of debate at all; it was to be replaced by dialectic by the fourteenth century. Certain other Islamic disciplines deal with language-related questions.

Muslim interest inMantiq and philosophy started in the Abbasid Caliphate (750-1258), approximately two centuries after the advent of Islam. In the Prophetic and Rashidin era (the early few decades of Islam)Mantiq philosophy were almost unknown for different reasons. It was the 'nation building' era. The proximity to the Prophet's times and the fresh understanding of the religion which was not influenced by the inter-cultural encounters with other nations raised no need for philosophy. In the Ummayyad era which succeeded the Rashidin Caliphate philosophy andMantiq were the business of non Muslims of the newly incorporated countries such as Syria.

According to Ibn Khuldun's theory of associating prosperity of science with urbanization early Muslims did not show interest in the sciences of old nations as those Muslims were not urbanized yet. When the Islamic State was firmly established and became prosperous they turned their attention to those sciences. The cumulative nature of knowledge and the emergence of Islamic schools of thought and sects contributed to the spread of logic and philosophy as tools to be employed by different groups albeit within the framework of Islam.

The schism which erupted between the intellectual leadership and the political leadership, and the big schism between Islamic sects (in particular Shiaites and Sunni Muslims) led each party to draw upon the Koran and Hadith (Prophet's Tradition), employ exegesis and manipulate human interpretations in ways that were not known during the time of the Prophet and the Rashidin Caliphs. This coincided with the intercultural encounter between Muslims and other nations particularly those which represented the most important centers of earlier civilizations prior to be incorporated within the Islamic civilizational orbit. These cultures were introduced into the controversy.

The Abbasid Caliphate witnessed arousing passion for philosophy among the ruling elite and Muslim scholars. Philosophy, besides that, continued as a business for non Muslims. For Muslims it was meant to be employed in the intra-and-inter religious dialogue and debate.

The above developments ushered in the translation movement which aimed to introduce those cultures particularly the Greek philosophy into Arabic. The beginning was with the Syriac decoctions of philosophy then the Aristotelian texts and commentaries. The translation movement continued to pick up momentum through the 9th century and by the 830s a circle of translators were closely coordinated around Al Kindi (d. 870) who

produced a short overview of the whole Organon and members of his circle produced an epitome of and commentary on the Categories; an epitome of On Interpretation; a version of the Sophisticated Fallacies; and probably an early translation of the Rhetoric. The great Syriac Christian translators Hunayn ibn Ishâq (d. 873) and his son Ishâq ibn Hunayn (d. 910) began to produce integral translations of complete works from the Organon, generally by way of Syriac translations. They translated the Categories, On Interpretation, Prior Analytics and Posterior Analytics. Ishâq provided revised translations of the Topics and the Rhetoric.

The Aristotelian Expositors

Al-farabi

Al-farabi was the outstanding contributor to the Aristotelian project, though not as a translator. Al farabi claimed that logic was indispensable for analyzing the argument-forms used in jurisprudence and theology, a claim that was to be taken up a century later by Abu Hamid al-Ghazali (d. 1111), thereby introducing the study of logic into the madrasa. To support his claim, Alfarabi wrote The Short Treatise on Reasoning in the Way of the Theologians …in which he interpreted the arguments of the theologians and the analogies (qiyâsât) of the jurists as logical syllogisms in accordance with the doctrines of the ancients.

Maybe Alfarabi is the first truly independent thinker in Arabic logic, a fact commemorated by bestowing upon him 'the Second Teacher' (after Aristotle). Al farabi was the first Muslim to bring Greek thinking closer to Islamic understanding, which, then pivoted around the codification and clarification of Qur'anic expression. al-Fiarabi was first and foremost a commentator of Aristotelian texts; his commentary on Aristotle's Organon served as the work of reference for other Muslim scholars. His work, however, went further in analogical reasoning to produce unique ideas not present in the Aristotelian original, and was dedicated to the inclusion of analogical inferences (transference). AI-FarabI's original contribution to analogical inference lay in his systematization of inductive reasoning under the rubric of the categorical syllogism. His intent was to raise the strength of analogy to that of a first order Aristotelian syllogism, i.e. a syllogism which does not deviate from the Greek rendering of two premises, a middle term, and the production of new knowledge which in turn may serve as a premise for further inferences. Drawing general or universal conclusions from premises generated by the scientific study of experience bodes well with the analogical framework of likewise generating general conclusions from particular instances of human experience-foreshadowing the methods of induction not yet fully developed in Western philosophical history. This commensurability between the formal syllogism and analogy is defended by al-Farabl when he uses what he calls "inference by transfer" or, as he notes of the mutakallimiln, "inference from evidence to the absent", or, as Kant would have it, from the phenomenal to the noumenal realms. The act of transference requires that the syllogism have a middle term, what analogy calls similarity. AI-Farabi further contends that, "if we are determined to have the 'transfer' be correct it is necessary that the 'matter' which is similar in the two compared objects be investigated. He presents a case depicting the (evident) createdness of animals or plants with the (absent) notion of createdness in the sky and the stars, and sets out to establish not only a middle term that denotes similarity, but one which also speaks of relevance. If both similarity and relevance obtain, then analogical inference takes on the form and strength of a first order syllogism, and a causal connection is established.

However, problems still arise when similarity might appear to obtain, but, in fact, does not. When this happens, analogical reasoning contains at

least one faulty premise that has not been detected by those forwarding an analogical argument. AI-Farabi refers to this distinction as the method of "raising" whereby conclusions are raised but do not obtain upon further logical investigation. However, leaving room for a legitimate analogy, al-Farabi then speaks of the method of "finding". 'Simply stated, al-Farabl reminds the reader that, "if one establishes a judgment by 'raising' it does not necessarily result that when one' finds' this thing (which is 'raised') one will 'find" the judgment (to be true); rather it is the converse of this that is necessitated, namely if one 'finds' the judgment, one 'finds' (also) the thing (in question)". In this sense, al-Farabi anticipates harsh criticisms against the analogy that he does not necessarily accept. Inductive and analogical arguments were converted into syllogisms making the cause or similarity in analogy the middle term in the syllogism", which compounded the difficulty of defining and determining the exact limits of qiyas. The force of the inferences made in an analogy is identical to those of a first figure syllogism because the similarity (' illa) is the subject term in the major premise and the predicate term in the minor. If the 'illa is absent when the judgment is absent...and present when the judgment is present... the 'illa is all the more true. If one removes animality, for example, from a thing, then one removes from this thing the property of being a man. But it is not necessarily true that if one finds an animal he also finds a man. Rather the converse is true; if one finds a man it necessarily follows that one finds an animal. To establish the truthfulness of a matter by the method of non existence, it necessarily follows that when the 'illa is found the judgment is also found. In order to ensure valid conclusions from an analogy (following this reasoning) the similarity ('illa), has to be relevant to the two cases; the judgments must be true of any case if it has the same' illa; the 'illa itself must be found and verified in each of the cases considered; it must be established that the judgment exists in all cases which possess an 'illa in common.  al-Farabi's importance lies in the fact that he placed heavy emphasis on the necessity and importance of the 'illa in all inferences: "For a complete inference and for achieving a high degree of certainty he insists that an illa must accompany the judgment". AI-Fariibi's marriage of analogy to the first order syllogism exists within a neo-Platonic and Aristotelian framework of metaphysics, replete with positivistic inclinations concerning the notions of cause and effect, and its importance for both logic and onto-logic. Thus, his legal concerns cross both «Islamic and Greek boundaries at their very source, and are less tied to simply the a priori sensibilities demanded by the more literal readings of the Koran that were adhered to by the mutakallimun. AI-Farabi managed to transform analogy into a first-figure syllogism, setting a standard by which the legal process could be developed. AI-Farabi had maintained, in accordance with his Neo-Platonic Aristotelian emanative position, that Allah was the God of metaphysical (i.e. causal) statements and that the Koran had to be interpreted metaphorically. This, along with discussions on logic and other sciences, was nonetheless accused of being un-Islamic, and the theological milieu remained highly antagonistic to the Greek "foreign"/heretical sciences. They rejected the concept of natural causation (i.e., arguing from cause to effect and from

effect to cause) that maintained that phenomenal acts advance from a thing's quiddity. They held the view that only divine will held the power to cause. It was in this manner, that they upheld the concept of divine omnipotence. And later, al-Farabi would become the focus of attacks directed against the "School of Baghdad".

Averroes (Ibn Rushd) and the End of Aristotelianism

Averroes was one of the last representatives of a dying Farabian Aristotelianism. Averroes was aware of Alfarabi's attempts to make sense of the difficulties in Aristotle's texts. In one such area, the modal logic, Averroes was to return to the problems four times through his career.

Averroes' project is illustrated in his Philosophical Essays, a number of which are on logical matters. Averroes defends and refines Alfarabi's account of the conversion of modal propositions and then uses that account as the basis of a new interpretation of the modal syllogistic. A second example of the way Averroes works is his reappraisal and vindication of Aristotle's doctrines of the hypothetical syllogistic against Avicenna's alternative division into connective and repetitive syllogisms (Averroes (1983) Maqâlât essay 9, 187-207).

In his fourth attempt to interpret Aristotle's modal system Averroes differs from Avicenna first and foremost by insisting on a consideration Avicenna has been at pains to remove from his syllogistic: is the subject picked out by a term essential to it?

Averroes' final system comprises two distinct aspects. The first aspect - not original to Averroes nor apparently to the Arabic tradition - is seeing the modality of a proposition as a function of the modality of its terms, which in turn is a function of how each term picks out what it refers to. The second aspect is that different classes of modal syllogism are differentiated by the types of terms occurring in them. Rather than looking on the modality of the proposition as something which belongs irreducibly to the proposition, Averroes classifies modals in the following way:

You should know that assertoric propositions have assertoric terms, necessary propositions necessary terms. By “necessary term” I mean that the term is one per se, and these propositions are composed of a subject and an essential predicate (mahmûl jawharî) of that subject, or a subject and an inseparable accident(‘arad lâzim ) belonging to that subject. Those propositions with assertoric terms are those which are composed of denominative terms which are sometimes present in the denominated thing and sometimes absent (sifât tûjad lil-mahmûl târatan wa-tufqad târatan ). But when one of these denominative terms is present in the subject, there must be present another denominative term that follows on it necessarily which is the predicate, as in: everything walking is moving. For when walking is actually present the thing must be moving; and when walking is withdrawn from it (irtafa‘ minhu ), so too is movement. These are the simple assertoric premises (al-muqaddamât al-wujûdiyya al-basîta ) which are atemporal (fî ghayri zamân ), and they are what Aristotle intends firstly to talk about in this book. Their subject and predicate alike are one per accidens (wal-mawdû‘ fîhâ wâhid bil-‘arad wa-ka-dhâlika l-mahmûl ). And there exists another kind of proposition that is partly assertoric and partly

necessary (min jiha wujûdî wa-min jiha darûrî ) - that is, the subject is composed of a substance and a changeable denomination (jawhar wa-sifa mutabaddila ), from which follows a predicate composed of the substance of the denomination and its intrinsic essential attribute (sifa jawhariyya gharîziyya ). The subject here is one per accidents and the predicate is one per se, for example, when we say that everything walking is an animal. And this is assertoric on account of the denomination of the denominated subject, and necessary on account of the predicate of the denomination. For walking, when it occurs, signifies an animal by discontinuous signification (fal-mashy idhâ wujida dalla ‘alâ l-hayawân dalâlatan ghayra dâ'ima ), but for the times at which walking is present in it. The subject of walking implies being an animal always (wa-mawdû‘u l-mashy yalzamuhu wujûdu l-hayawân dâ'iman ), because the subject of walking and what is denoted by that is necessarily an animal. And this proposition is in one respect necessary and in another assertoric (darûrîya min jiha wa-wujûdîya min jiha ) - necessary per accidens and assertoric per se (darûrîya bil-‘arad wa-wujûdîya bidh-dhât ). A proposition that conversely has a necessary subject and a predicate of assertoric matter (mâdda ) is just assertoric, and is not necessary per accidens. This is a temporal assertoric, I say, where the subject implies the predicate for a specified time, and necessity is not found in it, only a connexion of the predicate and subject merely for that time. The characteristic of this [proposition] is that the predicate is not connected to the subject for all times at which the subject exists, but only for a certain specified time. And so, as Aristotle says, syllogisms in the sciences are not constructed from this type of assertoric.

With a per se necessity proposition described above, he has truth-conditions which will allow him to make sense of Aristotle's claim that every J is necessarily B converts to some B is necessarily J. In fact, Averroes is able to replicate Aristotle's results with necessity and possibility premises (Thom (2003) 199). He does so, however, at the cost of having to slide between calling a proposition of type 3 a necessity proposition or an assertoric according to the dictates of the exegetical moment.

Dissention from Aristotelian Legacy

The Avicennan Tradition of the Twelfth Century

Avicenna (d. 1037) was beginning his career far away in the east, in Khurasan (Persia). Led by his Intuition, he presented himself as an autodidact able to assess and repair the Aristotelian tradition. Here is what he says in the Syllogism of the Cure, written about midway through his career:

'You should realize that most of what Aristotle's writings have to say about the modal mixes are tests, and are not genuine opinions - this will become clear to you in a number of places…' (Avicenna (1964), Qiyâs 204.10-12)

Of all his many works, it is Avicenna's Pointers and Reminders that had most impact on subsequent generations of logicians. From it we may note a few broad but typical differences from the Prior Analytics in the syllogistic. First, the “absolute” (mutlaqât , often translated “assertoric”) propositions have truth-conditions stipulated somewhat like those stipulated for possibility propositions (so that, for example, the contradictory of an absolute is not an absolute, absolute e-propositions do not convert, second-figure syllogisms with absolute premises are sterile). Secondly, Avicenna begins to explore the logical properties of propositions of the form every J is B while J. Thirdly, Avicenna divides syllogistic into connective (iqtirânî ) and repetitive (istithnâ'î ) forms, a division which replaces the old one into categorical and hypothetical (Avicenna (1971) al-Ishârât 309, 314, 374). We may call a logician “Avicennan” if he adopts these doctrines.

Avicennan logicians embarked upon repairing and reformulating Avicenna's work. Just as Avicenna had declared himself free to rework Aristotle as Intuition dictated, so too Avicenna's school regarded itself free to repair the Avicennan system as need arose, whether from internal inconsistencies, or from intellectual requirements extrinsic to the system. A major early representative of this trend is ‘Umar ibn Sahlan as-Sawi (d. 1148) who began, in his Logical Insights for Nasîraddîn, to rework Avicenna's modal syllogistic. It was to be his students and their students, however, who would go on to make the final changes to Avicennan logic that characterized the subject that came to be taught in the madrasa.

Tûsî and the Neo-Avicennan Response

The great Shî‘î scholar Nasiraddîn at-Tûsî (d. 1274) explains why Avicenna explores it the way he does:

What spurred him to this was that in the assertoric syllogistic Aristotle and others sometimes used contradictories of absolute propositions on the assumption that they are absolute; and that was why so many decided that absolutes did contradict absolutes. When Avicenna had shown this to be wrong, he wanted to give a way of construing those examples from Aristotle (Tusi (1971) Sharh al-Isharat 312.5-7).

Revisionist Avicennan Logicians

By and large, the Revisionists adopt most of Avicenna's distinctions and stipulations. But - on their preferred reading of the proposition - they reject, among other inferences. If every J is possibly B, and every B is necessarily A, it doesn't follow that every J actually becomes B such that it is necessarily A. Kâtibî does not ampliate the subject term to the possible (so that it would be understood as every possible B is necessarily A), nor does he read each proposition as being embedded in a necessity operator. Rather, he understands the possibility proposition as follows: there are Js, and whatever is at one time J is possibly B. This means that Kâtibî and the other Revisionists have a modal syllogistic that differs significantly from Avicenna's. The way the Revisionists put this difference is as follows:

Our statement every J is B is used occasionally according to the essence (hasab al-haqîqa ), and its meaning is that everything which, were it to exist, would be a J among possible individuals would be, in so far as it were to exist, a B; that is, everything that is an implicand of J is an implicand of B. And occasionally [it is used] according to actual existence (hasab al-khârij ), and its meaning is that every J actually (fî l-khârij ), whether at the time of the judgment or before it or after it, is B actually (fî l-khârij ).

The distinction between the two considerations is clear. Were there no squares actually (fî l-khârij ) it would be true to say a square is a figure under the first consideration and not the second; and were there no figures actually other than squares, it would be correct to say every figure is a square under the second consideration but not the first (Kâtibî (1948) Shamsiyya 91.1-4, 96.12-14).

In fact, the Revisionists are prepared to accept the Avicennan inferences given an essentialist reading of the propositions, but this is a half-hearted concession never pursued in their treatises. The question is why, and I conclude this section by speculating as to the answer.

Both groups, the Avicennan and the Revisionists, want to be able not only to trace valid inferences, they want also to use the system they produce for extra-logical purposes. They want arguments that are not only valid, but also sound, that is, arguments that are not only formally perfect, but that have true premises. To use the essentialist reading to say every cow is necessarily four-stomached, as an Avicennan would, is to claim necessarily, every cow is necessarily four-stomached; this is much stronger in one important respect than the Revisionist claim that there are actually cows, and everything that's actually a cow is necessarily four-stomached.

Ghazâlî and Logic

The twelfth century is one of the most complex periods of transformation in Muslim intellectual history. This period has been called the Golden Age of Arabic philosophy. The growth of logic in the preceding two centuries was concordant with the advance of the medical sciences and consequently it gained support with a wider audience. The century before had seen the advent of the madrasa as the prime institution of learning in the Islamic world (Makdisi (1981) 27-32), and Abu Hamid al-Ghazali (d. 1111) had been appointed to the most prestigious of these new institutions. Ghazali had successfully introduced logic into the madrasa which attracted much more gifted logicians (Gutas (2002). al-Ghazali took up Alfarabi's arguments in support of the utility of logic for theology and law, especially in his last juridical summa, Distillation of the Principles of Jurisprudence, a text which soon became a mainstay of the madrasa.

It is in this period that the major change in the coverage and structure of Avicennan logic occurred. The late twelfth century also saw Averroes produce what was effectively the last of the work in the Farabian tradition of logic, work which was to be translated into Hebrew and Latin but which was neglected by Arabic logicians. Finally, through the course of the twelfth century, the modified Avicennan logic that would be adopted by the logic texts of the madrasa began to emerge.

Ghazali argued that, properly understood, logic was entirely free of metaphysical presuppositions injurious to the faith. This meant that logic could be used in forensic reasoning:

We shall make known to you that speculation in juristic matters (al-fiqhiyyât ) is not distinct from speculation in philosophical matters (al-‘aqliyyât ) in terms of its composition, conditions, or measures, but only in terms of where it takes its premises from (Ghazâlî (1961) Mi‘yâr 28.2-4).

Ghazali tended to an even stronger position towards the end of his life: more than being merely harmless, logic was necessary for true knowledge. However for all his historical importance in the process of introducing logic into the madrasa, the logic that Ghazâlî defended was too dilute to be recognizably Farabian or Avicennan.

AI-Ghaziili's position was largely formed by both his philosophical preparation and his theological convictions. al-Ghazali as a jurist/theologian was very much interested in the logical questions that legal discussions could comprise. The attraction that the foreign sciences held for al-Ghazali was in direct relation to their usefulness in furthering the cause of theology. AI-Ghazali raised the possibility that these sciences could be demonstrably true and that they might have some bearing on religion, i.e., that when the specialized sciences (mainly logic and physics) offered demonstrations which conflicted with the literal readings of scripture, the latter must alter their status to one of metaphor. And because al-Ghazali held the view that God could not actuate something self-contradictory, literal readings should therefore be subjected to demonstrable proofs where and when they appear to exist. For example, when dealing with some of the well established facts of cosmology such as eclipses he writes: "thus, when one who studies these demonstrations and ascertains their proofs, deriving thereby information

about the times of the two eclipses, their extent and duration, is told that this is contrary to religion, he will not suspect this science, but only religion.

However, al-GhazalI also wanted to maintain that logic and the sciences were doctrinal1y neutral, particularly where the world of natural causation was concerned, and especially where they attempted to redefine the ontological stature of the Qur'an. He states:

"As for logical sciences, none of these relates to religion either by way of denial or by affirmation. They are no more than the study of the methods or proof and standards of reasoning, the conditions of the premises of demonstration and the manner of their ordering, the conditions of correct definition and the manner of its construction.

In rejecting "the principle of necessary causal connection" which was "the cornerstone of Aristotelian demonstrative science," al-Ghazal'i entered into a paradox viz. the logical sciences to which he was committed. How can logic and science adjudicate scriptures, but remain doctrinally neutral in its first principles? al-Ghazal'i's intent was not to indicate that demonstrative logic is philosophically uncommitted. In stead, his purpose lay in the impossible attempt to prove that its philosophical commitment is not given to an Aristotelian metaphysic.

Al-Ghazal'i was evidently reacting against what was then the well established refusal at the time, to integrate useful aspects of formal logic (i.e., the syllogism) into law. Attempting to avoid a contradictory position where logic is concerned, al-Ghazal'i maintained that logic could be disengaged from the heretical metaphysical framework in which it was imbedded and be used as a tool or method in the realm of al-fiqh. Whether he did so successfully or not is questionable. The answer given by al-Ghazali is motivated by theological reasons first and foremost. It is based on the parent eternal nature of the natural world implied by emanationist (causal) theories which attempt either to lower God's eternality to the finite stature of the world, or raise the finitude of the world to God's eternality, much in the way al-Farabi attempted to move from "evidence to absence". Both would be contradictory statements about the sovereign nature of God as stated in the Qur'an. Instead, al-Ghazali attempts to jettison the metaphysical aspects of Greek thinking, while harmonizing its logical tools with Islamic law.

Al-GhazalI's reformulation of the Greeks' tools of reasoning (qiyas/syllogism) relates primarily to matters of law which denote items given to "less clear speech" as opposed to "clear speech". These ambiguous legal aspects might suggest (I) finding a text relevant to the new case in the Qur'an or HadIth; (2) discerning the essential similarities or ratio legis between two cases; (3) allowing for differences lfuruq) and determining that they can be discounted; and (4) extending or interpreting the ratio legis to cover the new case. But under the auspicious abilities of qiyas that bore some affinity with a fortiori forms of reasoning, al-Ghazali endeavored to include analogy, and argumentum a simile. Al-Ghazal'i demarcates the qiyas from analogy only on the basis that the former bears certain knowledge, while the latter renders only probable inference. AI-GhazalI's insistence on converting analogy to a first figure syllogism, a reformulation of al-FarabI's

systemization of inductive reasoning, intentionally grounded legal theory in an Aristotelian framework of knowledge. Here an awareness of the dubious relationship between analogy and the syllogism (qiyas ) uncovers an inconsistency in the metaphysical system that supported it. We can leave aside the dichotomous application of logic given by al Ghazali who found it relevant in worldly (legal) affairs, but troublesome when impinging on established metaphysical norms, or theology (viz. the circumstances of God's unlimited freedom).

In sum it was Gazali's madrasa that provided the backbone of the tradition, and a number of jurists came time and again to stress that the study of logic was so important to religion as to be a fard kifâya, that is, a religious duty such that it is incumbent on the community to ensure at least some scholars are able to pursue its study. In Gazali's words:

As for the logic that is not mixed with philosophy ….  there is no disagreement concerning the permissibility of engaging in it, and it is rejected only by he who has no inkling of the rational sciences. Indeed, it is a fard kifâya because the ability to reply to heretical views in rational theology (kalâm), which is a fard kifâya, depends on mastering this science, and that which is necessary for a religious duty is itself a religious duty.

lbn Taymiyya

lbn Taymiyya is best considered a theologian and a jurist, one who often leveled polemical accusations at Greek logic. Like al-Ghazali, lbn Taymiyya was concerned with God's unlimited power and freedom of the divine will, and so rejected causal theories which would tie God explicitly to the natural world and qualify his involvement (causality) with his world. Thus, al1 forms of unitary exposition (universals) were rejected as conventions (nominal) by lbn Taymiyya.

Ibn Taymiyya's position rested on its own universal premise: that under no conditions can universals (of any kind) be established outside the mind of the one who experiences. Doubtless, the exception here is prophecy. This amounted to a rejection of universals altogether, i.e., an anti-realist and nominalist position in metaphysics which claims that where universals flourish in logical discourse, they do so only mental1y, and not (in any sense) in reality. Thus, universals can be established so long as it is understood that they function pragmatically within the specific needs of a given context, that which still demands a medium for human communication. Universals cannot obtain either metaphysically, or theologically, where there is open and full communication with God. The substance/accident debate collapses in Ibn Taymiyya's nomimalist schematic. Essence and accident are but arbitrary and relative demarcations set apart from each other in accordance with usage. Ibn Taymiyya writes: "Furthermore, there is no doubt that what the logicians held concerning the theory of definition is of their own invention...Accordingly, it is necessary for them to distinguish between what in their opinion is essential and what is not...whereby they deem one attribute, to the exclusion of the other, to be of the essence.' There is undoubtedly a strong element of relativism in Ibn Taymiyya's epistemological thinking, especially as he contends that "people differ in their faculties of perception in a way that cannot be standardized".

Ibn Taymiyya attacks the most delicate aspects of the syllogism-its definitions and concepts which support its larger (conceptual) relations. It is a strategy employed by lbn Taymiyya, simply because in order for a syllogism to function correctly (demonstrating true, false or even probable conclusions) an agreement must be reached concerning the definitional terms (i.e., the universality of its contents). Here, according to Ibn Taymiyya, philosophers and theologians, whether dealing with an analogy or a syllogism per se, assume too much in the way of universal terms that denote extra-mental realities. Ibn Taymiyya states:

"The universal exists only in the mind. If the particulars of a universal exist in the extra mental world, then this will be conducive to the knowledge that it is a universal affirmative".

The ideas penned by Ibn Taymiyya evoke Hume who also interrogated both philosophy and theology on the matter of universals and their relationship to the external world. In Book 1 (Of the Understanding) of his A Treatise of Human Nature, Hume reduces the perceptions of the human mind to what he calls impressions and ideas. Impressions are more immediate in their presence before the mind and feed our ideas that are faint and subject to greater discontinuity. Because Hume is considered an

empiricist, both impressions and ideas are necessarily derived from the external world. He writes:

"Now since nothing is ever present to the mind but perceptions, and since all ideas are derived from something antecedently present to the mind; it follows, that it is impossible for us so much as to conceive or form an idea of any thing specifically different from ideas and impressions."

 As is the case with Ibn Taymiyya, ideas and impressions are unable to form universals that can be placed back upon the external world. Hume writes:

"We can never really advance a step beyond ourselves, nor can conceive any kind of existence, but those perceptions, which have appeared in that narrow compass".

The logical conclusion of this position implies that nothing new in the way of knowledge could ever arise from syllogistics. Where definitions break down, so too does the idea of advancing new knowledge. Ibn Taymiyya holds that the links logicians make between concept and definition is too pronounced. He feels that concepts that belong to this or that vocational field are nothing more than an arbitrary invention of the logician. In a rather dogmatic view of conception (which has no need of formal definitions) Ibn Taimiyyah writes:

... all the communities of scholars, advocates of religious doctrines, craftsmen, and professionals know the things they need to know, and verify what they encounter in the sciences and the professions without speaking of definitions. We do not find any of the leading scholars discussing these definitions-certainly not the leading scholars of law, grammar, medicine, arithmetic- nor craftsmen, though they do form concepts of the terms used in their fields. Therefore, it is known that there is no need for these definitions in order to form concepts.

By attacking the heart of the syllogism (identity), Ibn Taymiyya is left with the circular question of just how legitimate rational concepts are established. He might agree that this presents a problem of sorts, but it is his dogmatism (or faith) which rescues him from having to deal with the problem of phenomena more earnestly. His argumentative style appears to suggest that while definitions are necessary for the articulation of logical concepts, the necessary definitions of existence are already established within the Qur'iin and have no need of logical analysis. Ibn Taimiyyah writes:

He who reads treatises on philology, medicine or other subjects must know what their authors meant by these names and what they meant by their composite discourse; so must he who reads books on law, theology, philosophy, and other subjects. The knowledge of these definitions is derived from religion, for every word is found in the Book of God, the exalted, as well as in the Sunnah of His Messenger.

The Decline

They is as yet so little explored of the logical activity in the post 1400s to the invasions of the Western powers. The first and most dangerous pitfall facing the historian is the assumption that there was a decline in logical studies in the realms under Muslim control that corresponds with the sixteenth century decline of the subject in early modern Europe. It is tempting to make this assumption but it needs to be examined and relevant texts must be edited and studied.