ABU’L-BARAKĀT AL-BAḠDĀDĪ, AWḤAD-AL-ZAMĀN HEBATALLĀH B. ʿALĪ B. MALKĀ BALADĪ, 5th-6th/11th-12th century physician and philosopher of Jewish origin, born in Balad, a town on the Tigris above Mosul. If Ẓahīr-al-dīn Bayhaqī’s information that he died in 547/1152 at the age of ninety solar years is approximately correct, he was born ca. 454/1062. According to another report, he died at the age of about eighty. In any case he can not have been born later than ca. 470/1077, since in 489/1096 he read the Ketāb al-talḵīṣ al-Neẓāmī with the author, Abu’l-Ḥasan Saʿīd b. Hebatallāh (d. 495/1101), his teacher of medicine in Baghdad. He may also have studied philosophy with the same teacher.

Few details are known about his career. He served the Saljuq sultan Ḡīāṯ-al-dīn Moḥammad Tapar (d. 511/1118) and wrote a treatise for him. The sultan accused him of treating him improperly and imprisoned him for some time. It may have been at the Saljuq court in western Iran that he met the Kakutid prince of Yazd, ʿAlāʾ-al-dawla Farāmarz b. ʿAlī b. Farāmarz, who became a champion of his philosophy and defended his criticism of Ebn Sīnā’s views against the slighting remarks of ʿOmar Ḵayyām. According to a gloss in Abu’l-Barakāt’s Ketāb al-moʿtabar, Abu’l-Barakāt’s statement that someone had seen his philosophical notes and asked him to publish them—which he refused to do at the time—refers to ʿAlāʾ-al-dawla.

After Sultan Moḥammad’s death, Abu’l-Barakāt probably served his son and successor Maḥmūd (511-25/1118-31). According to one report, he attended Maḥmūd’s wife, a daughter of Maḥmūd’s uncle, Sultan Sanǰar, in her last illness; but she died (524/1130). Fearing for his life from the sultan, Abu’l-Barakāt converted to Islam. Bayhaqī, however, relates that he was captured in the defeat of the caliph Mostaršed by Sultan Masʿūd b. Moḥammad in 529/1135; in order to save his life he became a Muslim and was rewarded by the sultan. Evidently Abu’l-Barakāt had gone to Baghdad to serve Mostaršed (512-29/1118-35) after leaving the service of Sultan Maḥmūd. He probably returned to Baghdad following Mostaršed’s defeat. Other reports place his conversion at the caliphal court. He served the caliph Moqtafī (530-55/1136-60) and apparently wrote his treatise on the intellect at his suggestion. It is his only work which distinctly reflects a Muslim outlook, containing quotations of the Koran and of sayings of ʿAlī. In 544/1149 he was called to Mosul to treat the Zangid ruler Sayf-al-dīn Ḡāzī, but was unable to save his life. Toward the end of his life he became blind and ill. When Sultan Masʿūd fell ill in 547/1152, Abu’l-Barakāt was brought from Baghdad to Hamadān. As he saw the sultan’s end approach, he feared for himself and, according to Bayhaqī, died on the same day as Masʿūd (29 Jomādā II 547/1 October 1152). His coffin was carried to Baghdad. The account of his contemporary, Bayhaqī, may have to be dismissed if it can be shown that the date (552/1157) given at the end of one manuscript of the treatise on the intellect is definitely that of its composition rather than a copy (see K. Vollers, Katalog der Handschriften der Universitätsbibliothek zu Leipzig II, Leipzig, 1906, p. 311). According to Ebn Abī Oṣaybeʿa, Abu’l-Barakāt in fact served the caliph Mostanǰed (555-66/1160-70); but his bare statement may be merely an inference from an anachronistic report he copied from Yāqūt. According to this report, Abu’l-Barakāt tried to defame his rival, the Christian physician Ebn al-Telmīḏ, through forged evidence, before the caliph Mostażīʾ (566-75/1170-80); but he failed and himself lost the caliph’s favor. Ebn al-Telmīḏ is known to have died before the reign of Mostażīʾ. The enmity between him and Abu’l-Barakāt is well attested; but Yāqūt’s report, if it has any historical basis, must refer to the reign of an earlier caliph.

Abu’l-Barakāt’s extant works include some pharmacological treatises (see A. Dietrich, Medicinalia Arabica, Göttingen, 1966, pp. 228-30); the treatise on the intellect, Maqāla fi’l-ʿaql (see M. T. Dānešpažūh, Fehrest-e mīkrūfilmhā-ye Ketābḵāna-ye Markazī-e Dānešgāh-e Tehrān, Tehran, 1348 Š./1969, p. 609), and a treatise on the cause of the visibility of the stars at night and their invisibility at daytime, Resāl a sabab ẓohūr al-kawākeb laylan wa ḵafāʾehā nahāran, written in answer to a question of Sultan Moḥammad Tapar. The latter treatise is in some manuscripts wrongly ascribed to Ebn Sīnā (tr. by E. Wiedemannn in Eders Jahrbuch für Photographie 1909, pp. 49-54). Largely unpublished is a lengthy commentary on Ecclesiastes in Arabic, containing discussions of philosophical problems. Abu’l-Barakāt dictated it at an advanced age to his student, the Jewish poet Esḥāq b. Ebrāhīm b. ʿAzrā of Cordova.

His chief work is the Ketāb al-moʿtabar, composed at a mature age on the basis of notes containing his philosophical reflections collected over a long period of time. Dealing with logic, natural sciences, and metaphysics, it is patterned after Ebn Sīnā’s Ketāb al-šefāʾ, which in some parts is copied almost literally. In other parts, however, Abu’l-Barakāt refuted the theses of Ebn Sīnā and espoused radically different views. Though his philosophical thought, as it emerges in the K. al-moʿtabar, lacks systematic consistency, it offers important new insights in various areas. While he often stands closer to the Platonic and Neoplatonic tradition vis-à-vis the Peripateticism of Ebn Sīnā, his disquisitions have a marked personal note. Characteristic is his reliance on a priori knowledge of self-evident facts as against the rational deductions of the Peripatetic doctrine. Thus he founded his psychology on the immediate consciousness man has of himself. This self-awareness had been adduced already by Ebn Sīnā as an incontrovertible proof of the existence of the soul. Ebn Sīnā, however, retained the Peripatetic theory of a multiplicity of faculties composing the soul, while Abu’l-Barakāt, again appealing to man’s certain consciousness of being one, rejected this multiplicity of faculties and maintained the unity of the soul in all its functions, conscious as well as unconscious. Accordingly he denied the distinction between the intellect and the soul, fundamental in Peripatetic doctrine, insisting that that which apprehends the intelligible and the sensible is one and the same. He also rejected as unreasonable the existence of a separate active intellect (ʿaql faʿʿāl) affirmed by the school of Ebn Sīnā as the proximate cause of human soul. In Abu’l-Barakāt’s view, human souls are caused by the souls of the stars. The soul is attached involuntarily to the body, which limits and directs the soul’s activity and perception. After death the soul returns to its source.

Abu’l-Barakāt’s concept of God differed profoundly from Ebn Sīnā’s. Against the negative theology of the latter, he affirmed the existence of essential attributes in God distinct from both his essence and his acts, which exist in their objects. This view obviously resembles the doctrine of the kalām theologians. The divine attributes of knowledge, wisdom, will, bounty, and power are the originative principles of the corresponding attributes in man and other existents, just as the existence of God is the originative principle of every existent. The attributes of other existents resemble those of God, in whom, however, they are perfect. God’s knowledge, too, is of the same nature as human knowledge. Abu’l-Barakāt rejected the fundamental Peripatetic thesis that in God subject, act, and object of intellection are identical; he held that God’s apprehension of his self is an act proceeding from his essence and thus can not be identical with it. He affirmed, against Ebn Sīnā, God’s knowledge of particulars in analogy to human knowledge. Yet God does not know all particulars, not because of any imperfection of his cognition, but because of the intrinsic impossibility of knowing an infinity. On this basis Abu’l-Barakāt restricts God’s foreknowledge and predetermination of events in the world, against the Sunnite Muslim doctrine of qażāʾ and qadar. This does not imply Muʿtazilite tendencies, since he affirmed that God may determine human acts which are subject to religious law. God’s knowledge of events depends on his directing his attention (eltefāt) to them. Thus he may respond to prayer and to newly arising circumstances. Similarly God’s will and action, though they can not encompass all events, may at any time and place interfere with their course. Abu’l-Barakāt rejected Ebn Sīnā’s proposition that only a single thing, the first intellect, can be caused directly by God.

Claiming the evidence of a priori certitude, Abu’l-Barakāt affirmed the existence of tridimensional, infinite space against the Arestotelian denial of space. He refuted the Peripatetic demonstration of the impossibility of the vacuum, relying partially on arguments used by John Philoponus. Quite original was his theory of time, which, he maintained, is recognized by a priori cognition to be intrinsically connected with being itself. He thus defined time as the measure of being, rejecting the Arestotelian definition of it as the measure, or number, of movement. Denying Ebn Sīnā’s distinction between time (zamān), aevum (dahr), and eternity (sarmad), he affirmed that God is not beyond time. He implies that the world has existed eternally, without stating this view explicitly. Abu’l-Barakāt’s theory of motion appears to be the first to imply the law of modern physics, that a constant force produces an accelerating motion rather than a constant one (maintained by the Arestotelian theory).

Though Abu’l-Barakāt did not leave a school, his views found supporters and opponents before and after his death. His contemporary ʿOmar b. Sahlān Sāvī devoted a treatise to refuting his criticism of Ebn Sīnā’s theory of God’s knowledge of particulars. Ẓahīr-al-dīn Bayhaqī, probably before 549/1154, wrote a refutation of the K. al-moʿtabar. Naṣīr-al-dīn Ṭūsī (d. 672/1274) in a special treatise criticized his thesis of the infinitude of space. On the other hand, Faḵr-al-al-dīn Rāzī (d. 606/1209) in his philosophical writings espoused many of Abu’l-Barakāt’s views. The Hanbalite opponent of philosophy, Ebn Taymīya (d. 728/1328), referred approvingly to some of his theses and criticisms of Peripatetic doctrine and ascribed his views, not quite plausibly, to the influence of his traditionalist Sunnite environment in Baghdad. Later eastern Muslim philosophers, among them Ḥosayn b. Moʿīn-al-dīn Maybodī (d. ca. 912/1506) and Mollā Ṣadrā Šīrāzī (d. 1050/1640), continued to discuss Abu’l-Barakāt’s views.


Bayhaqī, Tatemm a ṣewān al-ḥekma, ed. M. Šafīʿ, Lahore, 1935, pp. 110f., 150-53.

Yāqūt, Odabāʾ VII, p. 244. Ebn al-Qefṭī, Taʾrīḵ al-ḥokamāʾ, ed. J. Lippert, Leipzig, 1903, pp. 343-46.

Ebn Abī Oṣaybeʿa, ʿOyūn al-anbāʾ, Cairo, 1299/1882, I, pp. 255, 259f., 278-80.

Ebn al-ʿEbrī, Taʾrīḵ moḵtaṣar al-dowal, ed. A. Ṣāleḥānī, Beirut, 1958, pp. 207, 209f.

S. Nadvi, study at the end of the ed. of Abu’l-Barakāt, Ketāb al-moʿtabar, Hyderabad, 1358/1939, III, pp. 230-52.

S. Pines, “Ētudes sur Awḥad al-Zamân Abu’l-Barakât al-Baghdâdî,” Révue des études juives 103, 1938, pp. 4-64; 104, 1938, pp. 1-33.

Idem, Nouvelles études sur Awḥad al-Zamân Abu’l-Barakât al-Baghdâdî, Paris, 1955.

Idem, “La Conception de la Conscience de soi chez Avicenne et Abu’l-Barakât al-Baghdâdî,” Archives d’histoire doctrinale et littéraire du moyen âge 29, 1954, pp. 21-98.

Idem, “Studies in Abu’l-Barakāt al-Baghdādī’s Poetics and Metaphysics,” Scripta Hierosolymitana 6, ed. S. H. Bergman, Jerusalem, 1960, pp. 120-98.

The last four titles have been reprinted in The Collected Works of Shlomo Pines. Vol. I: Studies in Abu l-Barakāt al-Baghdādī. Physics and Metaphysics, Jerusalem, 1979.

(W. Madelung)

Originally Published: December 15, 1983

Last Updated: July 21, 2011

This article is available in print.
Vol. I, Fasc. 3, pp. 266-268

Cite this entry:

W. Madelung, “ABU’L-BARAKĀT BAḠDĀDĪ,” Encyclopædia Iranica, I/3, pp. 266-268; an updated version is available online at http://www.iranicaonline.org/articles/abul-barakat-al-bagdadi-awhad-al-zaman-hebatallah-b (accessed on 31 January 2014).