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-lirshād, 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. third/ninth 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 quotes the Baghdadi Muʿtazilī author Aḥmad ibn ʿAlī ibn al-Ikhshādh (d. 327/938) without mentioning a particular book title, but the fact that the quoted material focuses on consensus suggests that the quotation must derive from Kitāb al-Ijmāʿ (Book on Consensus), a title attributed to that author in bibliographical sources.45 He mentions that a certain Baghdādī holds the opinion that a consensus remains a consensus even when there is dissenting opinion on condition that the number of dissenters be small. While he does not give any name, this must be a reference to Muḥammad ibn Jarīr al-Ṭabarī, for he was a Baghdādī and is known to have voiced this unusual opinion. He must also have used the works of the prominent Shāfiʿī jurist Ibn Surayj. As studies advance, manuscripts are edited and published, and tools for cross-reference improve, it may be possible to identify additional works of uṣūl al-fiqh to which al-Qāḍī al-Nuʿmān had access, either directly or indirectly. As more early works are published, and as the fragments preserved in later works are studied more closely, the connections between Ikhtilāf uṣūl al-madhāhib and early uṣūl al-fiqh works will become clearer.
In an earlier publication, I argued that Ikhtilāf uṣūl al-madhāhib preserves extensive quotations from an early Ẓāhirī work of jurisprudence, al-Wuṣūl ilā maʿrifat al-uṣūl by Muḥammad ibn Dāwūd al-Iṣbahānī (d. 297/910).46 I now believe that a number of passages that I had earlier assigned to the chapter refuting analogy contained in that work actually derive from Ibn Dāwūd’s refutation of ʿĪsā ibn Ibrāhīm al-Ḍarīr, which apparently was devoted exclusively to analogy. Nevertheless, an examination of al-Qāḍī al-Nuʿmān’s quoted material suggests that he drew on al-Wūṣūl ilā maʿrifat al-uṣūl a great deal throughout Ikhtilāf uṣūl al-madhāhib; it is likely that he drew major arguments from that manual for several chapters of his work, perhaps more than I identified in the above-mentioned study. The main reason for his reliance on the work of Ibn Dāwūd was ideological: both the Ẓāhirīs and the Shiʿah in general, and al-Qāḍī al-Nuʿmān in particular, adopted a similar approach to legal interpretation. To borrow terms from Aron Zysow’s masterful study of Islamic legal theory, al-Qāḍī al-Nuʿmān, like most Shiʿi scholars, was a materialist, that is, a legal interpreter who demands certainty in formulations of the law. In contrast, his Sunni foes are formalists, who demand a correct procedure but not certainty, and who are comfortable dealing in realms of probability rather than certainty.47 For al-Qāḍī al-Nuʿmān, probability has no place in the formulation of Islamic law. Since there is a living Imam who may be consulted in difficult cases, in theory he does not have to confront uncertainties in the law. Ibn