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 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 Baghdadi 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 Baghdadi 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 Dāwūd provided al-Qāḍī al-Nuʿmān many sophisticated arguments against the same principles of hermeneutics that al-Qāḍī al-Nuʿmān sought to prove invalid, including not only analogy but also taqlīd and istiḥsān. In al-Qāḍī al-Nuʿmān’s view, the Ẓāhirīs’ adoption of istidlāl “inference” as a hermeneutic principle is contradictory, for in his view it is just as subjective and subject to human error as analogy and the other methods are. One might go so far as to suggest that the Ikhtilāf is based primarily on al-Wuṣul ilā maʿrifat al-uṣūl not only in much of its content but also in its form.
In al-Qāḍī al-Nuʿmān’s presentation on the whole, three topics loom larger than the rest: consensus (ijmāʿ), analogy (qiyās), and legal interpretation (ijtihād). As explained above, he first wrote the work in response to a debate on the issue of ijtihād in particular, and to a treatise devoted exclusively to ijtihād that a Ḥanafī opponent had written to refute his views on the topic. One would therefore expect a focus on this issue in particular in the Ikhtilāf. In addition, however, the emphasis on ijtihād may result from the fact that it represents in a more obvious manner than some of the other hermeneutic methods he cites the subjective element involved in interpreting the law. One could say the same of qiyās. Even more than ijtihād, though, qiyās had long been the subject of intense polemics both within Sunni Islam and between Sunnis and Shiʿah. The Shiʿah had inherited numbers of reports attributed to the Imams, some of which al-Qāḍī al-Nuʿmān cites, that denounce the use of analogy in the determination of Islamic law. In some of these, the Imam Jaʿfar al-Ṣādiq is portrayed as debating Abū Ḥanīfah on the matter. While these debates appear to be anachronistic, it is likely that they date from several generations before al-Qāḍī al-Nuʿmān was writing and had grown out of intense debate on this topic in particular.
It is likely that al-Qāḍī al-Nuʿmān focuses on consensus to the extent that he does—it is the longest chapter of his work—because it is the principle most often used to exclude the Shiʿah from the pale of Islam. It was the symbol of Sunni unity, the theological doctrine that implies that the Sunni community, which is envisaged as deriving from the early Islamic community under the Prophet and the rightly guided caliphs, is the saved sect of Islam. In addition, this concept more than any other was used by proponents of the Sunni legal madhhabs as a means to exclude Shiʿi jurists from being considered in the establishment of orthodoxy and in debate over Islamic law and doctrine.48 Furthermore, the topic of consensus seems to have occupied a central concern in early works of uṣūl al-fiqh, for it appears to have been placed first in books such as al-Ṭabarī’s al-Bayān ʿan uṣūl al-aḥkām.49
Al-Qāḍī al-Nuʿmān devotes significant attention to analogy and other similar concepts because they are gap-filling tactics used to flesh out God’s legislation, and he has no need for such hermeneutic procedures because the living Imam could theoretically resolve all difficult issues immediately. The situation of the Ismaʿilis was thus quite different from that of the Sunnis, and also from that of the contemporary Twelver Shiʿah, whose Imam was in occultation and unavailable for direct consultation.
Overall, al-Qāḍī al-Nuʿmān strives to denounce Sunni hermeneutic techniques for their subjective element. When he states, at several points in the work, that they all amount to the same thing, despite their difference in labels, this is the point he is stressing. Fallible humans have no right to determine what God’s law is of their own accord, and all the probabilistic methods of interpretation that they are employing are tantamount to doing just that. Instead, jurists should determine the law by consulting the Qurʾan and the Practice of the Prophet, and they should be guided in their interpretation by the opinions of the Imams, whose authority is established by the Qurʾan itself. This is a guarantee of certainty, and deviations from this system lead to uncertainty, which is unacceptable in matters of God’s law.
Sustained polemic exchanges often have the unintended effect of making the two sides resemble each other,
