ABU’L-QĀSEM AL-BALḴĪ AL-KAʿBĪ, ʿABDALLĀH B. AḤMAD B. MAḤMŪD (d. Šaʿbān, 319/February, 931), administrator and intellectual of Persian descent, Hanafite jurist and foremost representative of the Moʿtazela in Khorasan. His father had known ʿAbdallāh b. Ṭāher (d. 230/844) personally. Abu’l-Qāsem seems to have stood in a long kottāb tradition (see Taʾrīḵ Baḡdād XII, p. 340.10f.). In his youth he had been secretary to Moḥammad b. Zayd Dāʿī, the Zaidite ruler of Ṭabarestān (d. 287/900; cf. W. Madelung, Der Imām al-Qāsim ibn Ibrāhīm, Berlin, 1965, p. 159). Two decades later he was nominated vizier by Aḥmad b. Sahl b. Hešām Marvazī, the governor of Khorasan for the Samanid Naṣr b. Aḥmad II, who had installed himself at Balḵ (Yāqūt, Odabāʾ I, p. 147.6f.). When Aḥmad b. Sahl rebelled against his sovereign and was defeated in 307/919, Abu’l-Qāsem was put into prison. He was released shortly afterward on the initiative of ʿAlī b. ʿĪsā, who at that time was the deputy of Moqtader’s nominal vizier Ḥāmed b. al-ʿAbbās and exercised the real power in Baghdad (see Ebn al-Nadīm, Fehrest [Tehran], p. 219, n., lines 6f.).

Abu’l-Qāsem’s prestige in Baghdad dated from the time he studied there under the Muʿtazilite Ḵayyāṭ (d. ca. 300/913) and the grammarian Mobarrad (d. 285/898). In those days he had been admitted to the salon (maǰles) of the well-known Persian litterateur and Muʿtazilite Abū Aḥmad Yaḥyā b. ʿAlī Monaǰǰem Nadīm (d. 300/913), who considered him an authority in kalām (ibid., lines 8f.). After leaving capital he corresponded with Ḵayyāṭ and with the father of the grammarian Marzobānī (d. 384/994; cf. Taʾrīḵ Baḡdād IX, p. 384.16ff.). In his later years he stayed in Khorasan, where he was regarded as uncrowned king of theologians (emām ahl al-arż; see Mātorīdī, Ketāb al-tawḥīd, ed. Kholeif, Beirut, 1970, p. 49.17). In Balḵ his prestige was matched only by that of his contemporary and friend, Abū Zayd Balḵī (d. 322/934), whom, however, he had to defend against accusations outside his home country (cf. Yāqūt, Odabāʾ I, p. 147.6f.; Dāwūdī, Ṭabaqāt al-mofasserīn, ed. ʿA. M. ʿOmar, Cairo, 1392/1972, I, p. 42.14ff.). In Nasaf he was received with honor and given a teaching position (ʿoqeda laho maǰles; cf. the Taʾrīḵ Nasaf by Jaʿfar b. Moḥammad Mostaḡferī, 350-432/961-1041, quoted by Samʿānī, Ansāb [Leiden], fol. 485a.7f.). The local tradition claimed that even in Mecca his name aroused public interest (cf. the same source, quoted by Ebn Šāker Kotobī in his unpublished ʿOyūn al-tawārīḵ).

While Abu’l-Qāsem’s theological works were indeed read in Iraq, his influence was more extensive in Khorasan. He wrote, for example, a Ketāb maḥāsen Āl Ṭāher which shows his special attachment to the Taherids (Kašf al-ẓonūn [Istanbul], p. 1608). In addition there is his Ketāb maḥāsen Ḵorāsān (or Fażāʾel Ḵorāsān) which was used by Ebn al-Nadīm for the biography of Ebn al-Rēwandī (Fehrest, p. 216.13); the Moʿtazela did not see a need for a biography of Ebn al-Rēwandī. In contrast to his teacher Ḵayyāṭ, Abu’l-Qāsem did not attack Ebn al-Rēwandī’s famous “heretical” books; he only refuted his criticism of Jāḥeẓ’s thesis that the Koran is free from additions and omissions (quotations in Qāżī ʿAbd-al-Jabbār, Taṯbīt dalāʾel al-nobūwa, Beirut, 1966, pp. 62.12ff., 548) and his doctrine of tawallod (he quotes the book in his Ketāb al-maqālāt). He also corrected some errors in Ebn al-Rēwandī’s Adab al-ǰadal (Ebn ʿAsāker, Tabyīn kaḏeb al-moftarī, Damascus, 1347/1929, p. 131.15ff.). The title of his Ketāb al-sonna wa’l-ǰamāʿa (see Fehrest, p. 219, n., line 15) shows that he did not see a contradiction between his Muʿtazilite ideas and the Hanafite terminology of his eastern surroundings. In two of his works he polemicized against Moḥammad b. ʿĪsā Borḡūṯ from Sīrāf (d. 240/854 or 241/855), who represented the predestinarian wing of the Hanafite tradition. With Abū Jaʿfar Moḥammad b. ʿAbd-al-Raḥmān b. ʿOmar Ebn Qobba from Ray (who, according to Ebn Abi’l-Ḥadīd, had been his pupil but then went over to the Emāmīya) he carried on a long exchange of views on the problem of emāma which resulted in two publications from his hand, both of them refutations of books written by Ebn Qobba (see Naǰāšī, Reǰāl, Bombay, 1397/1899, p. 191). Whether he met the famous physician Moḥammad b. Zakarīyāʾ Rāzī (d. 313/925) in Ray, Baghdad, or somewhere else on their respective journeys is not clear. They discussed the concept of time and engaged in an extensive written dispute on several topics in Rāzī’s Ketāb al-ʿelm al-elāhī (cf. Rāzī, Opera philosophica, ed. P. Kraus, Cairo, 1939, pp. 167f.). Abu’l-Qāsem certainly kept a greater distance from Rāzī’s ideas than did his contemporary Abū Zayd Balḵī, with whom Rāzī seems to have studied (see GAS III, p. 275). Of the Iraq motakallemūn he disagreed mainly with Jobbāʾī (d. 303/915), head of the competing Baṣra branch of the Moʿtazela—e.g., on his doctrine of divine will and of the most fitting (aṣlaḥ; cf. his Naqż ketāb Abī ʿAlī al-Jobbāʾī fi’l-erāda and his Nehāya fi’l-aṣlaḥ ʿalā Abī ʿAlī, quotations of which may be found in Qāżī ʿAbd-al-Jabbār, Moḡnī, Cairo, 1960-65, XIV, pp. 55.14, 61.9ff.).

His most important works have a systematic and summarizing character. He wrote a twelve volume Tafsīr (Kašf al-ẓonūn [Istanbul], p. 448) of which quotations survive in the Amālī of Šarīf Mortażā (Cairo, 1954, I, pp. 468.10ff., 514, bottom; II, p. 364.16ff.) and perhaps in Mātorīdī’s Ketāb al-tawḥīd. His Ketāb awāʾel al-adella fī oṣūl al-dīn is quoted by Maqdesī (Badʾ I, p. 135.5f.); its chapter on the Christians was refuted by the Christian philosopher Ebn Zoṛʿa (331-98/943-1008; P. Sbath, Vingt traités philosophiques et apologétiques d’auteurs arabes chrétiens, Cairo, 1929, pp. 52f.). His ʿOyūn al-masāʾel which comprised three volumes was used by Abū Rašīd Nīsābūrī (d. 460/1068) in his Masāʾel al-ḵelāf bayn al-baṣrīyīn wa’l-baḡdādīyīn (GAS I, pp. 626f.). The late stage of theological development inside the Moʿtazela is reflected in a number of further masāʾel and maǰāles works in which Kaʿbī seems to have discussed scattered questions of detail. Most important for later generations were his Maqālāt al-eslāmīyīn, which were extensively used by Ašʿarī in his Maqālāt, Qāżī ʿAbd-al-Jabbār in his Fażl al-eʿtezāl and Moḡnī, Baḡdādī and Šahrastānī, Našwān Ḥemyarī in his Ketāb al-ḥūr al-ʿīn, Ebn Abi’l-Ḥadīd in his Šarḥ nahī al-balāḡa, and Ḥoǰūrī in his Ketāb rawżat al-aḵbār (GAL S. I, p. 587). A manuscript of the work has been found in Yemen by Foʿād Sayyed and was partly edited by him (Fażl al-eʿtezāl wa ṭabaqāt al-moʿtazela, Tunis, 1974, pp. 63f.). The book seems to have undergone several recensions. Kaʿbī used material which he had received from Ḵayyāṭ, and he corresponded with him from Khorasan in order to clarify unresolved questions (ibid., p. 297.3ff.). Later he seems to have combined the book with his ʿOyūn al-masāʾel (Fehrest, p. 219, n., lines 13ff.). This might explain why he says in the introduction to the text preserved in the Yemenite manuscript that he began writing it after 290/903, while Ḥāǰǰī Ḵalīfa gives the date 279/892 (Kašf al-ẓonūn [Istanbul], p. 1782), and why the manuscript differs sometimes from the quotations found in Našwān Ḥemyarī and elsewhere.

Kaʿbī was greatly interested in methodology and hermeneutics. He wrote at least two books on ǰadal and one on inference by analogy (estedlāl be’l-šāhed ʿala’l-ḡāʾeb). In his Naqż al-Sīrǰānī, a refutation of the Hanbalite Ḥarb b. Esmāʿīl b. Ḵalaf Kermānī Sīrǰānī (d. 288/901; cf. Ḏahabī, Ḥoffāẓ II, Hyderabad, 1388/1968, p. 613, no. 638; and Ebn Abī Yaʿlā, Ṭabaqāt al-Ḥanābela, Cairo, 1371/1952, I, p. 145, no. 189), he discussed the relevance of isolated Traditions (āḥād, i.e., the vast majority of aḥādīṯ according to the Moʿtazela) for human acting (Qāżī ʿAbd-al-Jabbār, Fażl al-eʿtezāl, p. 195.1ff.). In his Ketāb al-ḡorar wa’l-nawāder he defended the inevitability of eǰtehād (quotation in Mofīd, al-Foṣūl al-moḵtāra, 2nd ed., Naǰaf, n.d., I, p. 66). Most interesting for us is, however, his Ketāb qabūl al-aḵbār wa maʿrefat al-reǰāl, which presents a thorough and sometimes sarcastic criticism of many early authorities on Hadith; it is preserved in the ms. Cairo, moṣṭalaḥ 14m (GAS I, p. 623). Nevertheless, Kaʿbī is quoted as an authority on Hadith by a Khorasani moḥaddeṯ as renowned as Moḥammad b. Zakarīyāʾ Nasafī (d. 344/955; cf. Samʿānī, Ansāb [Leiden], p. 485a.9; and Ḏahabī, Ḥoffāẓ, p. 930, no. 833).

Any attempt to reconstruct Kaʿbī’s system would be premature at the present stage of research. This is not so much due to a lack of information, as is the case for the earlier Muʿtazilites, but rather to a lack of perspective. The texts we have do not present broad outlines and main ideas, but concentrate on refinement of proofs and other questions of detail. With Kaʿbī in Baghdad and Jobbāʾī in Baṣra, Muʿtazilite thought had reached the point of an overall systematization. We would be able to appreciate its full spectrum if we possessed complete, original works and knew more about the earlier phases. We can only assume that Kaʿbī’s ideas corresponded more or less to those of the Baghdad school and that they prepared the way for its astonishing influence during at least the next century and a half. Yet we are unable to determine the extent of his originality. We get most of our material from systematic works such as Mātorīdī’s Ketāb al-tawḥīd and Abū Rašīd Nīsābūrī’s Masāʾel al-ḵelāf (ed. M. Zīāda and R. Sayyed, Beirut, 1979; cf. M. Horten, Die Philosophie des Abu Raschid, Bonn, 1910; and A. Biram, Die atomistische Substanzlehre aus dem Buch der Streitfragen zwischen Basrensern und Baghdadensern, Berlin, 1902) and to a lesser extent in Qāżī ʿAbd-al-Jabbār’s Moḡnī and in Imamite treatises such as the Awāʾel al-maqālāt by Shaikh Mofīd (d. 413/1022; tr. D. Sourdel in REI 40, 1972, pp. 217ff.). Future research will have to start here. As matters stand, even the brief summary which follows may well be seriously out of focus.

The Baghdad tradition taken over from Ḵayyāṭ is characterized by respect for the laws of nature and a cautious handling of the concept of God’s omnipotence. Kaʿbī believed in the existence of natural qualities (ṭabāʾeʿ) which determine the functioning of bodies and guarantee the preservation of the species (cf. Horten, pp. 100ff.). For example, life depends on the ṭabāʾeʿ of food (ibid., p. 149). Kaʿbī followed the Greek view of the elements. Thus he proved that air can be changed into water through the condensation of vapor (Biram, Substanzlehre, p. 45). Man can produce heat and dryness (Horten, Philosophie, pp. 92, 149). Correspondingly, God does not have the power to let a heavy object float in the air (ibid., p. 140), and pain is not possible in dead substance (ibid., p. 129). On most of these points he was attacked by the Baṣra school, i.e., the followers of Jobbāʾī, who stressed instead God’s power to hold the world together and to change its laws against habit (ʿāda). On this point Jobbāʾī took up ideas of Abu’l-Hoḏayl, while Kaʿbī came closer to Naẓẓām. But in contrast to Naẓẓām he was an atomist, although again with opinions which differ from those of the Basrans. He did not believe in the existence of a void; to defend this standpoint he engaged in a number of experiments with appropriate explanations (ibid., pp. 37f.; Biram, Substanzlehre, pp. 37ff.; also the corresponding passage in Abū Rašīd, Fi’l-tawḥīd [identical with Zīādāt šarḥ al-oṣūl?], ed. M. ʿA. Abū Rīda, Cairo, 1385/1965, p. 419.14ff.). No two substances can be separated without something between them (Biram, pp. 36f.). An isolated atom has neither dimension nor direction; it does not move, nor can it be seen. All these qualities occur only through combination with at least one other atom (ibid., pp. 15ff., 46, 49; Horten, Philosophie, pp. 37, 139). This does not mean that two or more atoms without dimension form a body with dimension; it is rather the accidental combination (taʾlīf) which makes the difference (cf. S. Pines, Beiträge zur islamischen Atomlehre, Berlin, 1936, pp. 6f.). Accidents, however, do not exist continuously; they last only for a moment (Horten, Philosophie, pp. 79ff., 134; Ašʿarī, Maqālāt al-eslāmīyīn, Istanbul, 1929, p. 358.2ff.). Therefore, colors and elementary qualities such as heat or dryness are not permanent. On the other hand, substances can not exist without them (Biram, Substanzlehre, text, p. 43, bottom, cf. tr., p. 56; and Baḡdādī, Oṣūl al-dīn, Istanbul, 1346/1948, p. 56.15f.). They last only through the accident of endurance (baqāʾ), and vanish if God does not create this accident (Biram, Substanzlehre, pp. 63, 70).

Kaʿbī’s anthropology was not as elaborate. He seems to have focused only on theologically relevant points, especially the discussion of capability (esteṭāʿa). As an accident, capability can not last for two moments. It exists before the act, but not during it (Ašʿarī, Maqālāt, p. 230.5ff.). Capability is related to an organ; e.g., capability to speak can not be used for seeing, etc. (Horten, Philosophie, pp. 154f.). Incapability (ʿaǰz), on the other hand, is universal; it is the contrary of the positive and of the negative action alike, e.g., of both belief and unbelief. It is not identical with an external hindrance (māneʿ), for an external hindrance is contrary to an action. Incapability, however, is contrary to the capability to act (ibid., pp. 155ff.). Death is an entity in itself (maʿnā), not just the absence of life (ibid., pp. 150f.).

Kaʿbī’s ideas about God diverge little from those of other Muʿtazilites, especially his teacher Ḵayyāṭ. In agreement with most of his earlier colleagues, with some opposition among his later contemporaries, he believed that God is everywhere, though only in the sense that He knows and preserves all (cf. Mātorīdī, Tawḥīd, Beirut, 1970, pp. 75.3ff.; Madelung, Qāsim ibn Ibrāhīm, p. 115). God’s will is not an independent attribute, as the Basrans believed in agreement with Abu’l-Hoḏayl, but either identical with producing what He wills or with His order to produce it (when what He wills is an action to be performed by man). This idea was taken over from Naẓẓām (Madelung, Qāsim ibn Ibrāhīm, pp. 165ff.). Kaʿbī added the psychological explanation that the human will functions in connection with man’s ignorance or imperfect knowledge of the realizability of his intention. God’s omniscience and omnipotence thus make His will superfluous (cf. Šahrastānī, Nehāyat al-eqlām, ed. A. Guillaume, Oxford, 1931, p. 240.2ff.). Similarly God’s seeing and hearing are nothing other than His knowing (cf. Baḡdādī, Farq bayn al-feraq, ed. M. Badr, p. 166.4ff.; ed. M. M. ʿAbd-al-Ḥamīd, Cairo, p. 181.6ff.). Kaʿbī evidently tried to reduce the number of attributes to a few basic ones. This is perhaps why he did not define the ṣefāt al-feʿl in the usual way, as those attributes whose opposites can equally well be attributed to God, but rather subsumed them under His omnipotence. Thus in the beginning God was not creating, compassionate, etc., but He had the power to make His essence so (cf. Mātorīdī, Tawḥīd, p. 53.3f.). Like Naẓẓām, Kaʿbī thought that God must do the best (aṣlaḥ; cf. Qāżī ʿAbd-al-Jabbār, Moḡnī XIV, p. 55.14ff.; and Brunschwig in Stud. Isl. 35, 1974, p. 11). Theoretically speaking, He can do wrong; but if this really happened all our established categories would be shattered. It would not be against reason, but all the proofs on which reason bases itself would have to be changed to their opposites (i.e., God would have to change the order of the universe; cf. Ašʿarī, Maqālāt, p. 557.12ff.).

In the domain of epistemology Kaʿbī’s conceptual refinement seems to have exerted considerable influence. The standard definitions of both knowledge (ʿelm) and thinking (naẓar) seem to stem from him (J. van Ess, Erkenntnislehre des ʿAḍudaddīn al-Īcī, Wiesbaden, 1965, pp. 72, 244). He advocated a less intellectual outlook than his Basran colleagues; in contrast with them he allowed the unquestioning acceptance of a statement by an accepted authority (taqlīd), provided that this statement is true. The common people are not obliged to reflect on a given dogmatic issue, especially as some of them are unable to do so; a general knowledge is sufficient (the doctrine of the so-called aṣḥāb al-ǰomal; cf. ibid., pp. 73, 46 ; Horten, Philosophie, pp. 178, 193). Knowledge of God is meritorious, but even more so the contemplation which leads to it; although God can not be the object of this contemplation since He is still unknown (ibid., p. 182). Since human nature does not change, contemplation continues in the hereafter. The problem that there can be no reward for a meritorious act performed in paradise was solved by the assumption that contemplation then originates merely through recollection of former contemplation and therefore does not cause any effort (van Ess, Erkenntnislehre, p. 123).

In his political views Kaʿbī supported the right of the Qorayš to leadership of the community. He would acknowledge, however, a non-Qorayši sovereign in case of imminent civil war (Baḡdādī, Oṣūl al-dīn, p. 275.10f.). He had strong Zaydī sympathies (Madelung, Qāsim ibn Ibrāhīm, pp. 77f.), and in correspondence with Zaydī doctrine he stressed that the early Šīʿa did not reject Abū Bakr and ʿOmar (cf. Qāżī ʿAbd-al-Jabbār, Taṯbīt dalāʾel al-nobūwa, p. 62, bottom, and p. 548, bottom.


See also EI 2 I, pp. 1102-03, with additional references.

He is mentioned several times in Brockelmann, GAL, with some confusion; cf. S. I, p. 343, and 2nd ed., II, p. 665 (ad 206); versus 2nd ed., I, p. 447, and S. I, p. 619.

He is quoted twice in Kaḥḥāla, I, p. 286; VI, p. 31.

Sezgin, GAS I, pp. 622f.

Zereklī, Aʿlām2 IV, p. 189.

A. S. Tritton, Muslim Theology, London, 1947, pp. 157f.

W. M. Watt, Free Will and Predestination, London, 1948, pp. 80f.

A. N. Nader, Le système philosophique des Muʿtazila, index.

M. Moḥaqqeq, Fīlsūf-e Ray Moḥammad b. Zakarīyā-ye Rāzī, Tehran, 1349 Š./1970, pp. 31f.

W. M. Watt, The Formative Period of Islamic Thought, Edinburgh, 1973, index.

F. Sayyed, intro. to his ed. of part of Kaʿbī’s Maqālāt al-eslāmīyīn, Tunis, 1974, pp. 43f.

(J. van Ess)

Originally Published: December 15, 1983

Last Updated: July 21, 2011

This article is available in print.
Vol. I, Fasc. 4, pp. 359-362

Cite this entry:

J. van Ess, “ABU’L-QĀSEM KAʿBĪ,” Encyclopædia Iranica, I/4, pp. 359-362; an updated version is available online at http://www.iranicaonline.org/articles/abul-qasem-al-balki-al-kabi-abdallah (accessed on 31 January 2014).