Logic ( ) played an important
role
in Islamic
philosophy.
Islamic law and
jurisprudence 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
ancient Greek 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.
Ibn Hazm (994-1064) wrote the
Scope of
Logic, in which he stressed on the importance of
sense perception as a source
of knowledge. 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.
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.
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).
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.
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. 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.
Avicennian logic
Dimitri Gutas and the
Stanford Encyclopedia of
Philosophy consider the period between the 11th and 14th
centuries to be the "
Golden Age" of
Arabic and Islamic philosophy, initiated by
Al-Ghazali's successful integration of logic into
the
Madrasah curriculum and the subsequent
rise of
Avicennism.
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,
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. The first
criticisms on Aristotelian logic were also written by Avicenna, who
developed an original theory on
temporal modal
syllogism. 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.
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.
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. In the 14th century,
Ibn Khaldun, in his
Muqaddimah (1377), wrote the following on
how Islamic logic had changed since the 12th century:
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.
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
See also
References
- Wael B. Hallaq (1993), Ibn Taymiyya Against the Greek
Logicians, p. 48. Oxford University Press, ISBN
0198240430.
- Muhammad
Iqbal, The
Reconstruction of Religious Thought in Islam, "The Spirit
of Muslim Culture" (cf. [1] and [2])
- Seyyed Hossein
Nasr and Oliver Leaman (1996), History of Islamic
Philosophy, pp. 107-109, Routledge, ISBN 0415056675.
- Ibn Hazm, Islamic Philosophy
Online.
- 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.[3]
- 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. Ibn al-Nafis As a Philosopher, Encyclopedia of
Islamic World).
- Seymour Feldman (1964), "Rescher on Arabic Logic", The
Journal of Philosophy 61 (22), p. 724-734
[726].
- Richard F. Washell (1973), "Logic, Language, and Albert the
Great", Journal of the History of Ideas
34 (3), p. 445-450 [445].
- Lenn Evan Goodman (1992), Avicenna, p. 188,
Routledge, ISBN
041501929X.
- History of logic: Arabic logic, Encyclopædia
Britannica.
- Lenn Evan Goodman (2003), Islamic Humanism, p. 155,
Oxford University Press, ISBN
0195135806.
- Dr. Lotfollah Nabavi, Sohrevardi's Theory of Decisive Necessity and kripke's QSS
System, Journal of Faculty of Literature and Human
Sciences.
- 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.
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