the turn of the tenth century with the Ṭabaqāt aṣḥāb Ibn Ḥanbal of Abū Bakr Aḥmad ibn Muḥammad al-Khallāl (d. 311/923), the Mālikī madhhab in the tenth century with the Kitāb al-Ṭabaqāt fī man yarwī ʿan Mālik wa-atbāʿihim min ahl al-amṣār of Ibn Abī Dalim (d. 351/962), the Shāfiʿī madhhab with the Kitāb fī ṭabaqāt al-Shāfiʿiyyah of Abū al-Ṭayyib Ṭāhir ibn ʿAbd Allāh al-Ṭabarī (d. 450/1058), and the Ḥanafī madhhab much later, with the Ṭabaqāt al-Ḥanafiyyah of Ṣalāḥ al-Dīn ʿAbd Allāh ibn Muḥammad al-Muhandis (d. 769/1367) and al-Jawāhir al-muḍiyyah by Ibn Abī al-Wafāʾ al-Qurashī (d. 775/1373).35 While such works do embody a claim to authority, the formation of a legal madhhab may not necessarily be accompanied by the compilation of such a work by one of its prominent members. I argued that Makdisi overlooked notable ṭabaqāt works, particularly in the Ḥanafī madhhab, while also suggesting that a lost work by al-Ṭabarī, Kitāb Marātib al-ʿulamāʾ, was actually devoted to the classes of jurists and represented a conscious claim to religious authority on behalf of al-Ṭabarī’s own legal school, the Jarīrī madhhab.36 In addition, I have argued that it had become a necessity for legal schools to have a manual of uṣūl al-fiqh, that is, jurisprudence, legal hermeneutics, or legal theory, in order to be recognized as authoritative. By the end of the ninth century, the Ḥanafī, Mālikī, Shāfiʿī, Ẓāhirī, and Jarīrī madhhabs all had substantial manuals of uṣūl al-fiqh, most of which are not extant. The Ḥanbalī madhhab, as well as the Imami and Zaydi Shiʿi madhhabs, appears to be a latecomer in this regard.37
The Sunni legal system exerted pressure on outside groups to conform or at least to respond to their increasing control over public and scholarly religious discourse. Makdisi already noted that in reaction to the increasing hegemony of the jurists, theologians “infiltrated” the legal madhhabs.38 Muʿtazilah in general chose affiliation with the Ḥanafī madhhab, and Ashʿarī theologians opted for affiliation with the Shāfiʿī legal madhhab. I have argued that Twelver Shiʿah primarily chose affiliation with the Shāfiʿī legal madhhab.39 In the late ninth and early tenth centuries, the Twelver or Imami Shiʿah affiliated with the Ẓāhirī madhhab as well.40 The Zaydis affiliated primarily with the Ḥanafī madhhab early in their history, in Iraq and Iran, and centuries later in Yemen with the Shāfiʿīs. It is likely as well that Khārijī and Ismaʿili Shiʿi jurists affiliated with one or another of the Sunni legal madhhabs in some periods and regions, but this topic has not been investigated.
At the same time, the rise in the hegemony of the jurists of the Sunni legal madhhabs over Islamic legal discourse provoked another sort of reaction among the potentially excluded groups: the effort to establish other legal madhhabs on a par with those of the Sunnis. I have described this process in some detail for the Twelver Shiʿah, who established the Imami madhhab in Baghdad in the tenth and eleventh centuries, particularly through the efforts of al-Shaykh al-Mufīd (413/1022), al-Sharīf al-Murtaḍā (d. 436/1044), and al-Shaykh al-Ṭūsī (d. 460/1067).41 The Zaydis evidently did the same during the same period; a key figure in this regard was the Imam al-Nāṭiq bi-l-Ḥaqq (d. 422/1033).42 Less is known about the Khārijī tradition, but at least certain elements in their legal literature show a similar trend. Al-Qāḍī al-Nuʿmān’s overall project was to establish Ismaʿili law on a par with the legal schools of the Sunnis, and Ikhtilāf uṣūl al-madhāhib must be viewed as part of that effort. Even though his conception of religious authority and the structure of the legal school differed radically from those of the Sunni jurists, he certainly had the Sunni legal schools in mind while he was writing his works.
Shedding Light on the Early History of Islamic Legal Theory
Lokhandwalla realized already in 1972 that Ikhtilāf uṣūl al-madhāhib was a crucial text because it sheds light on the early history of Islamic legal theory in general, and not just on that promoted by the Fatimid state. Ikhtilāf uṣūl al-madhāhib is arguably one of the most important sources for the early history of the genre of uṣūl al-fiqh (jurisprudence, legal theory, or legal hermeneutics). Its merit lies in the fact that, despite some corruption of the text, it is integral and complete and sets out to provide, in the course of a sustained refutation, a comprehensive survey of Sunni theories of jurisprudence as they existed in the mid-tenth century. Al-Qāḍī al-Nuʿmān, and the author whose treatise he set out to refute, had access to many other Sunni works of jurisprudence or legal hermeneutics (uṣūl al-fiqh). In the course of the text itself, al-Nuʿmān remarks several times that he is merely summarizing the Sunnis’ arguments so as not to bore the reader, such as, for example, when he presents the arguments for the authority of consensus.43 Altogether, he may be citing scores of Sunni works of uṣūl al-fiqh, either directly or through intermediate sources. This is particularly important because most of the seminal works in this genre from the ninth and tenth centuries have not been preserved. The material they contained is only known from later bibliographies and scattered fragments and quotations. Between the Risālah of al-Shāfiʿī and the Muʿtamad of Abū al-Ḥusayn al-Baṣrī (d. 436/1044), composed in the early eleventh century, few works from this genre have survived, the main exceptions being the Fuṣūl of Abū Bakr al-Jaṣṣāṣ al-Rāzī (d. 370/981) and the seventeenth volume of the Mughnī of al-Qāḍī ʿAbd al-Jabbār (d. 415/1025), both of which are missing sections, crucially the introductions, which may have provided important information on the authors’ aims and intentions in writing the work as well as the prior history of the genre. Along with these, one half of another important work from the late tenth century, al-Bāqillānī’s (d. 403/1013) al-Taqrīb wa-l-irshād, has survived; it, too, is missing the introduction.
Al-Qāḍī al-Nuʿmān informs us that he wrote Ikhtilāf uṣūl al-madhāhib in response to an opponent with whom he debated the validity of ijtihād, legal interpretation or the exhaustive independent investigation of a legal question. He claims that he soundly defeated his opponent, but that the opponent subsequently collected a treatise in one fascicle (kurrāsah) reporting the opinions of those who upheld the validity of legal interpretation and presenting their proofs of its validity. He writes that he quoted in his book all the arguments that the opponent had presented in his treatise, and added any other of their arguments which were available to him. Then, he decided to refute all the other hermeneutical principles to which the Sunnis resort in their jurisprudence, and not just legal interpretation (ijtihād): the arbitrary adoption of views on authority (taqlīd), consensus (ijmāʿ), speculative reasoning (naẓar), analogy (qiyās), preference (istiḥsān), and inference (istidlāl), as we see in the completed work.44
Moreover, al-Qāḍī al-Nuʿmān had a large number of Sunni uṣūl al-fiqh texts at his direct disposal and often quotes or paraphrases material from these works. The identification of these works is rendered difficult by the fact that al-Qāḍī al-Nuʿmān rarely refers to the books that he is citing or paraphrasing by title, and in most cases refers to the authors in question only obliquely. Al-Qāḍī al-Nuʿmān mentions very few works by title in the course of his refutation: Adab al-qāḍī and Ikhtilāf al-Shāfiʿī wa-Mālik by al-Shāfiʿī, al-Mujarrad by al-Ḥasan ibn Ziyād al-Luʾluʾī (d. 204/819–20), a student of Abū Ḥanīfah, and a refutation of ʿĪsā ibn Ibrāhīm al-Ḍarīr’s (fl. 3rd/9th c.) work on legal analogy (qiyās) by Muḥammad ibn Dāwūd (d. 297/910). Comparison of the text of his quotations shows that he also quoted al-Shāfiʿī’s works on legal theory al-Risālah, Jimāʿ al-ʿilm, and Ibṭāl al-istiḥsān. The small number of explicitly designated works does not negate the fact, however, that al-Qāḍī al-Nuʿmān is arguing against a sophisticated system of jurisprudence which had been presented in a highly developed tradition of Sunni works by his time and that he is quoting directly from scores of important works, most of which are no longer extant. In some cases, we can identify particular works, at least tentatively. Al-Qāḍī al-Nuʿmān