Logic in Islamic philosophy

Logic (Arabic: "Mantiq") played an important role in early Islamic philosophy. Islamic law placed importance on formulating standards of argument, which gave rise to a novel approach to logic in Kalam, as seen in the method of "qiyas". This approach, however, was later displaced to some extent by ideas from Greek philosophy and Hellenistic philosophy with the rise of the Mu'tazili school, who highly valued Aristotle's "Organon". The works of Hellenistic-influenced Islamic philosophers were crucial in the reception of Aristotelian logic in medieval Europe, along with the commentaries on the "Organon" by Averroes.

Important developments made by Muslim logicians included the first forms of non-Aristotelian logic, notably Avicennian logic, and the introduction of temporal modal logic and inductive logic. Other important developments in early Islamic philosophy include the development of a strict science of citation, the isnad or "backing", and the development of a scientific method of open inquiry to disprove claims, the ijtihad, which could be generally applied to many types of questions.

History

According to the Routledge Encyclopedia of Philosophy:

Logic in Islamic law and theology

Early forms of analogical reasoning, inductive reasoning and categorical syllogism were introduced in Fiqh (Islamic jurisprudence), Sharia (Islamic law) and Kalam (Islamic theology) from the 7th century with the process of "Qiyas", before the Arabic translations of Aristotle's works. Later during the Islamic Golden Age, there was a logical debate among Islamic philosophers, logicians and theologians over whether the term "Qiyas" refers to analogical reasoning, inductive reasoning or categorical syllogism. Some Islamic scholars argued that "Qiyas" refers to inductive reasoning, which Ibn Hazm (994-1064) disagreed with, arguing that "Qiyas" does not refer to inductive reasoning, but refers to categorical syllogism in a real sense and analogical reasoning in a metaphorical sense. On the other hand, al-Ghazali (1058-1111) (and in modern times, Abu Muhammad Asem al-Maqdisi) argued that "Qiyas" refers to analogical reasoning in a real sense and categorical syllogism in a metaphorical sense. Other Islamic scholars at the time, however, argued that the term "Qiyas" refers to both analogical reasoning and categorical syllogism in a real sense. [Wael B. Hallaq (1993), "Ibn Taymiyya Against the Greek Logicians", p. 48. Oxford University Press, ISBN 0198240430.]

Ibn Hazm (994-1064) wrote the "Scope of Logic", in which he stressed on the importance of sense perception as a source of knowledge.Muhammad Iqbal, "The Reconstruction of Religious Thought in Islam", "The Spirit of Muslim Culture" (cf. [http://www.allamaiqbal.com/works/prose/english/reconstruction] and [http://www.witness-pioneer.org/vil/Books/MI_RRTI/chapter_05.htm] )] He wrote that the "first sources of all human knowledge are the soundly used senses and the intuitions of reason, combined with a correct understanding of a language." He also criticized some of the more traditionalist theologians who were opposed to the use of logic and argued that the first generations of Muslims did not rely on logic. His response was that the early Muslims had witnessed the revelation directly, whereas the Muslims of his time have been exposed to contrasting beliefs, hence the use of logic is necessary in order to preserve the true teachings of Islam. [Seyyed Hossein Nasr and Oliver Leaman (1996), "History of Islamic Philosophy", pp. 107-109, Routledge, ISBN 0415056675.]

Ibn Hazm's "Fisal" ("Detailed Critical Examination") also stressed the importance of sense perception as he realized that human reason can be flawed, and thus criticized some of the more rationalist theologians who placed too much emphasis on reason. While he recognized the importance of reason, since the Qur'an itself invites reflection, he argued that this reflection refers mainly to sense data, since the principles of reason are themselves derived entirely from sense experience. He concludes that reason is not a faculty for independent research or discovery, but that that sense perception should be used in its place, an idea which forms the basis of empiricism. [ [http://www.muslimphilosophy.com/hazm/ibnhazm.htm Ibn Hazm] , "Islamic Philosophy Online".]

Al-Ghazali (Algazel) (1058–1111) had an important influence on the use of logic in theology, as he was the first to apply the Avicennian system of temporal modal logic to Islamic theology. Despite the logical sophistication of al-Ghazali, the rise of the Ash'ari school from the 12th century slowly suffocated original work on logic in western Islamic regions such as the Maghreb and al-Andalus, but logic continued to be studied in eastern Islamic regions such as the Levant, Egypt and Persia.

Ibn al-Nafis (1213-1288) wrote two major works dealing with logic in Islamic theology. "Theologus Autodidactus" was a fictional story dealing with many Islamic topics. Through its story, Ibn al-Nafis attempted to establish that the human mind is capable of deducing the natural, philosophical and religious truths of Islam through logical thinking. In "A Short Account of the Methodology of Hadith", he demonstrated the use of logic in the classification of the hadiths into four categories: decidedly true ("maclūm al-sidq"), probably true ("yuz annu bihi'l-sidq"), probably false ("yuz annu bihi'l-kadhb") and decidedly false ("maclūm al-kadhb"). [Nahyan A. G. Fancy (2006), "Pulmonary Transit and Bodily Resurrection: The Interaction of Medicine, Philosophy and Religion in the Works of Ibn al-Nafīs (d. 1288)", p. 67-73, "Electronic Theses and Dissertations", University of Notre Dame. [http://etd.nd.edu/ETD-db/theses/available/etd-11292006-152615] ]

Aristotelian logic

Most early Muslim logicians during the 8th and 9th centuries produced commentaries on Aristotelian logic. The first original Arabic writings on logic were produced by al-Kindi (Alkindus) (805–873), who produced a summary on earlier logic up to his time.

Ibn Rushd (Averroes) (1126–1198) was the last major logician from al-Andalus, who wrote the most elaborate commentaries on Aristotelian logic. He was also the last major Aristotelian logician from the Islamic world. Though his commentaries on Aristotelian logic and metaphysics had little influence in the Islamic world, his commentaries had a strong influence on medieval Europe after the Latin translations of the 12th century.

The last major logician to write a commentary on Aristotelian logic was Ibn al-Nafis (1213-1288), though he himself was not an Aristotelian logician. He wrote the "Al-Wurayqat" ("The Little Papers"), a commentary on Aristotle's "Organon" and "Rhetoric".Dr. Abu Shadi Al-Roubi (1982), "Ibn Al-Nafis as a philosopher", "Symposium on Ibn al-Nafis", Second International Conference on Islamic Medicine: Islamic Medical Organization, Kuwait (cf. [http://www.islamset.com/isc/nafis/drroubi.html Ibn al-Nafis As a Philosopher] , "Encyclopedia of Islamic World").]

Alfarabian logic

Though al-Farabi (Alfarabi) (873–950) was mainly an Aristotelian logician, he introduced a number of non-Aristotelian elements of logic. He discussed the topics of future contingents, the number and relation of the categories, the relation between logic and grammar, and non-Aristotelian forms of inference. He is credited for categorizing logic into two separate groups, the first being "idea" and the second being "proof".

Al-Farabi also introduced the theories of conditional syllogism and analogical inference, which were not part of the Aristotelian tradition. [Seymour Feldman (1964), "Rescher on Arabic Logic", "The Journal of Philosophy" 61 (22), p. 724-734 [726] .] Another addition al-Farabi made to the Aristotelian tradition was his introduction of the concept of poetic syllogism in a commentary on Aristotle's "Poetics". [citation|title=The Islamic roots of the poetic syllogism|journal=College Literature|date=February 1996|last=Ludescher|first=Tanyss|url=http://findarticles.com/p/articles/mi_qa3709/is_199602/ai_n8749610 |accessdate=2008-02-29]

Avicennian logic

Ibn Sina (Avicenna) (980–1037) developed his own system of logic known as "Avicennian logic" as an alternative to Aristotelian logic. After the Latin translations of the 12th century, Avicennian logic also influenced early medieval European logicians such as Albertus Magnus, [Richard F. Washell (1973), "Logic, Language, and Albert the Great", "Journal of the History of Ideas" 34 (3), p. 445-450 [445] .] though Aristotelian logic later became more popular in Europe due to the strong influence of Averroism.

Avicenna developed an early theory on hypothetical syllogism, which formed the basis of his early risk factor analysis. He also developed an early theory on propositional calculus, which was an area of logic not covered in the Aristotelian tradition. [Lenn Evan Goodman (1992), "Avicenna", p. 188, Routledge, ISBN 041501929X.] The first criticisms on Aristotelian logic were also written by Avicenna, who developed an original theory on temporal modal syllogism. [http://www.britannica.com/ebc/article-65928 History of logic: Arabic logic] , "Encyclopædia Britannica".] He also contributed inventively to the development of inductive logic, being the first to describe the methods of agreement, difference and concomitant variation which are critical to inductive logic and the scientific method.Lenn Evan Goodman (2003), "Islamic Humanism", p. 155, Oxford University Press, ISBN 0195135806.]

Fakhr al-Din al-Razi (b. 1149) criticised Aristotle's "first figure" and formulated an early system of inductive logic, foreshadowing the system of inductive logic developed by John Stuart Mill (1806-1873). Systematic refutations of Greek logic were written by the Illuminationist school, founded by Shahab al-Din Suhrawardi (1155-1191), who developed the idea of "decisive necessity", which refers to the reduction of all modalities (necessity, possibility, contingency and impossibility) to the single mode of necessity. [Dr. Lotfollah Nabavi, [http://public.ut.ac.ir/html/fac/lit/articles.html Sohrevardi's Theory of Decisive Necessity and kripke's QSS System] , "Journal of Faculty of Literature and Human Sciences".] Ibn al-Nafis (1213-1288) wrote a book on Avicennian logic, which was a commentary of Avicenna's "Al-Isharat" ("The Signs") and "Al-Hidayah" ("The Guidance"). Another systematic refutation of Greek logic was written by Ibn Taymiyyah (1263-1328), who wrote the "ar-Radd 'ala al-Mantiqiyyin" ("Refutation of Greek Logicians"), in which he gave a proof for induction being the only true form of argument, which had an important influence on the development of the scientific method of observation and experimentation. The "Sharh al-takmil fi'l-mantiq" written by Muhammad ibn Fayd Allah ibn Muhammad Amin al-Sharwani in the 15th century was the last major Arabic work on logic. [Nicholas Rescher and Arnold vander Nat, "The Arabic Theory of Temporal Modal Syllogistic", in George Fadlo Hourani (1975), "Essays on Islamic Philosophy and Science", p. 189-221, State University of New York Press, ISBN 0873952243.]

Fuzzy logic

In 1965, Lotfi Asker Zadeh founded fuzzy set theory as an extension of the classical notion of set and he founded the field of Fuzzy Mathematics.

Later in 1973, Zadeh founded the field of Fuzzy logic. This was the first major contribution to logic from the Islamic world after more than five centuries.

Major figures in Islamic logic

*Al-Kindi ("Alkindus") (805–873)
*Al-Farabi ("Alfarabi") (873–950)
*Ibn Sina ("Avicenna") (980–1037)
*Ibn Hazm (994-1064)
*Al-Ghazali ("Algazel") (1058–1111)
*Ibn Rushd ("Averroes") (1126–1198)
*Fakhr al-Din al-Razi (1149-1210)
*Shahab al-Din Suhrawardi ("Sohrevardi") (1155-1191)
*Ibn al-Nafis (1213-1288)
*Ibn Taymiyyah (1263-1328)
*Muhammad ibn Fayd Allah ibn Muhammad Amin al-Sharwani (15th century)
*Lotfi Asker Zadeh (b. 1921)

ee also

*Early Islamic philosophy
*History of logic
*Logic
*Mill's Methods

References

Resources

* [http://www.rep.routledge.com/article/H017 Logic in Islamic philosophy] , Routledge Encyclopedia of Philosophy. Routledge, 1998. (Alternatively, see [http://www.muslimphilosophy.com/ip/rep/H017 Logic in Islamic philosophy] )
* [http://www.formalontology.it/islamic-philosophy.htm Ancient Islamic (Arabic and Persian) Logic and Ontology] , at Raul Corazzon's "Ontology. A resource guide for philosophers".