'AQL, intellect or intelligence, the Arabic equivalent to Greek noËw.

(1) In neoplatonic speculation, which in many respects resembles the late Greek doctrine of the
Logos and also in many respects corresponds to the Logos christology, 'aql is the first, sometimes
the second, entity which emanates from the divinity as the first cause, or proceeds from it by
means of intellectual creation, nafs and tabi'a etc. coming after 'aql in succession. As first created
entity the 'aql is also called 'the representative' or 'the messenger' of God in this world. The
neoplatonic idea of 'aql as first creation also appears in the hadith: 'The first thing created by God
was the 'aql etc.' (cf. I. Goldziher, Neuplatonische und gnostische elemente im Hadit, ZA, 1908, 317 ff.).
[Cf. also falsafa, ikhwan al-safa'; for the role of 'aql in Isma'ilism, isma'iliyya and duruz; for 'aql
in sufi theosophy, e.g. ibn 'arabi and 'abd al-razzaq al-qashani].
(Tj. de Boer*)

(t) According to the theologians (mutakallimun), 'aql is a source of knowledge and, as such, is the
antithesis of naql or tradition (see e.

g. I. Goldziher, Vorlesungen über den Islam, ch. iii); the words fitra and tabi'a (fisiw) are also used for
it. 'Aql is thus a natural way of knowing, independently of the authority of the revelation, what is
right and wrong. (Thus it corresponds to the lÚgow of the Stoics, who understood by this term a
'natural light' (lumen naturale), which was their criterion for distinguishing between good and
bad.) This 'aql, possessed by all human beings, is also called al-ra'y al-mushtarak (al-Farabi, R. fi
'l-'Aql (Bouyges); cf. the koina‹ ¨nnoiai of the Stoics and the koinÚw noËw of Alexander of
Aphrodisias, De anima (Bruns)). Allied to this meaning of 'aql is the view qualified by al-qFarabi
(op. cit.) and Ibn Sina (al-Hudud) as that of the masses (al-dhumhur), according to which 'aql must
lead to praiseworthy conduct, so that a man of bad character, however ingenious he might be,
is not an 'aqil (cf. the ÙryÚw lÚgow of the Stoics and the distinction made by Aristotle between
frÚnhsiw and panourg¤a, Nic. Ethics); 'aql here means 'wisdom'.

(3) The philosophers of Islam followed in their accounts of 'aql Aristotle and his Greek
commentators, more especially Alexander of Aphrodisias. According to them 'aql is that part of
the soul (for their psychology in general see nafs) by which it 'thinks' or 'knows' and as such is
the antithesis of perception. Mostly, however, 'aql is not regarded as a part of the soul at all,
which is then restricted to the lower mental functions, but as an incorporeal and incorruptible
substance differing in kind from the soul--an ambiguity which also pervades Aristotle's
psychology. 'Aql is broadly divided into the theoretical (al-nazari) and the practical intellect
(al-'amali); the former apprehends the quiddities or universals, while the latter deliberates about
the future actions and through the appetitive faculty moves the body to the attainment of the

The development of the theoretical intellect in man is the most widely and richly discussed
subject of the doctrine. In a brief and rather obscure passage (De anima, iii, 5) Aristotle had said
that the potential intellect in man is actualized by an eternally actual intellect (an application of
the general Aristotelian principle that for the realization of a potentiality the agency of
something already actual is necessary); the latter acts upon it as light acts upon our faculty of
sight or art on its material. The disparity between the two analogies obscures Aristotle's view of
the relationship between the passive and active intellects, but it was Alexander's interpretation
which provided the basis for the Arabs' discussions. According to Alexander (op. cit.) our
intellect is initially a pure potentiality which is actualized by the active intellect which is God;
when our actualized intellect is not operating, it is intellectus in habitu, which in actual operation
becomes intellectus in actu. Most of the succeeding commentators, especially Themistius and
(pseudo-)Philoponus (Stephanus), reject Alexander's equation of the active intellect with God
and declare it to be a part of the human soul. According to Muslim philosophers, the active
intellect ('aql fa''al) is the lowest of the separate intelligences, which gives individual forms to
material objects and universal forms to the human intellect--hence its name: wahib al-suwar (dator
formarum of the later scholastics). According to al-Farabi (op. cit.) the first stage of actualization
consists of the abstraction of forms from matter by the 'light' of the active intelligence: the
second stage is reached when the thus actualized intellect ('aql bi 'l-fi'l = intellectus in effectu)
reflects upon itself and attains to a knowledge of the categories and becomes 'aql mustafad
(intellectus acquisitus or adeptus). According to Ibn Sina (al-Shifa', De anima) the potential intellect
('aql bi 'l-quwwa, or 'aql hayulani = intellectus potentialis or materialis) reaches the first stage of its
actualization when it acquires the axiomatic truths (this is called 'aql bi 'l-malaka = intellectus in
habitu), the second stage (called 'aql bi 'l-fi'l = intellectus in actu) when it acquires the secondary
intelligibles from the primary intelligibles or axioms, the final stage ('aql mustafad = intellectus
acquisitus) when it actually contemplates these intelligibles and becomes similar to the
activeqintellect. Ibn Sina, inspired by Neo-platonism, affirms that the universal cannot be
acquired by abstraction from the particulars, but by direct intuition from the active intelligence.
The final stage of human bliss comes when the human intellect becomes one with the active
intellect, which happens, according to al-Farabi and Ibn Sina, only after death, although Ibn
Rushd allows such a union during earthly life.

One of the chief difficulties of this whole Greco-Arabic doctrine is the individuality of intellect
which they affirm to be incorporeal and therefore, according to their general principle of
individuation by matter, universal. Although its individuality is recognized, seeing that the
subject of thought is the individual 'I', the basic principle of their theory of knowledge, viz. that
of the identity of subject and object (a principle laid down by Aristotle in order to ensure the
objectivity of knowledge, but rejected by Ibn Sina), prevented the formulation of the individual
ego. This difficulty culminated in Ibn Rushd (De anima), who declared the intellect to be one for
all humanity, while recognizing that his theory did not do justice to the individuality of the act
of thought.

(4) The Muslim philosphers recognized a hierarchy of separate intelligences ('uqul mufariqa), each
lower one emanating from the higher. These incorporeal beings, usually ten in number and
endowed with life, intuitive thought and bliss in varying degrees, create and govern their
respective spheres which themselves are regarded as being possessed of souls. Like the
Greco-Christian thinkers (e.g. (pseudo-)Philoponus, De anima (Hayduck), 5t7), the Muslims
identified the separate intelligences with certain angels, the lowest of these, the active intellect,
called Gabriel, being the ruling 'aql of the sublunar sphere.

(F. Rahman)


A. Günsz, Die Abhandl. des Alex. v. Aphrod. über den Intellect, Leipzig thesis 1886

Farabi, Fi 'l-'Aql, ed. Bouyges

idem, Fi Ithbat al-Mufariqat, Hyderabad

idem, al-Siyasa al-Madaniyya, Hyderabad

Dict. of technical terms, ii, 10t6 ff.

Maimonides, Le guide des egares, ed. transl. Munk, i, 301 ff.

ii, 51 ff., 66 ff., T. J. de Boer, Zu Kindi und seiner Schule, Arch. f. Gesch. d. Phil., 1899, 17t ff.

idem, Gesch. d. Phil. im Islam, especially 94 ff., 105 ff.

M. Steinschneider, Al Farabi, St. Petersburg 1869, 90 ff.

Kitab Ma'ani al-Nafs, ed. and comm. I. Goldziher, Gkttingen 1907, 41 ff.

idem, La onzieme intelligence, RAfr, 1906, t4t f.

E. Gilson, Les sources greco-arabes de l'augustinisme avicennisant, Archives d'Histoire Doctrinale et
Litteraire du Moyen Age, 19t9-30

B. Nardi, S. Tommaso d'Aquino, Trattato sull' Unita dell'Intelletto contro gli Averroisti, Florence 1938

F. Rahman, Avicenna's Psychology, Oxford 195t, 33-56, 116-1t0

G. Vadja, Juda ben Nissim ibn Malka, Paris 1954, 74-9.

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Source: from the Encyclopedia of Islam --© 1999 Koninklijke Brill NV, Leiden, The Netherlands