Since the time of the Mishnah, few themes have been more central to Jewish thought than Oral Torah. The rabbis expound on unwritten traditions at every turn and they extol orally transmitted teachings as hallmarks of authentic revelation and its interpreters. But one looks in vain for extended metareflections on Oral Torah in the rabbinic corpus. At most, short passages imagine a capacious revelation at Sinai or highlight Oral Torah as a distinctive feature of true Israel, in opposition to other scriptural religions.
If this was apparently adequate for the rabbis of late antiquity, Jews in the medieval Islamicate world required longer and more systematic considerations of Jewish law. Starting in the tenth century with the later geonim, Jews in the Islamic world began to ask “big” questions about rabbinic literature, its authority and its authenticity. Where did it come from? How did it work? And why should it matter? Both Qaraites (who rejected rabbinic authority) and Rabbanites (who championed it) pondered such problems. But the nature, scope, and function of Oral Torah did not stem only, or even primarily, from the Qaraite-Rabbanite debate; instead, constructions of the sages were central to Jewish self-understanding and even, one might say, to imaginings of “Judaism” itself.
Rabbanite depictions of Oral Torah were inevitably produced in dialogue with neighboring Muslim thinking about Islamic law. This is in part because understanding oneself often takes shape by understanding the Other. But more fundamentally, After Revelation shows that Jews found ready-made models that could be applied to rabbinic literature in nearby Islamic legal theory; these helped shape their past to meet needs of their present. That is, by thinking through their own law using the “legal theory of the gentiles,” as one gaon put it,[1] Jews placed Jewish law on sound theoretical footing in ways that would have been compelling in the medieval Mediterranean.
The understanding that Jews engaged with a full sweep of Islamic sciences was arguably one of the earliest insights of modern Jewish historiography; indeed, medieval Jews were sometimes explicit about turning to non-Jewish sources. But scholarship has traditionally highlighted Jewish engagement with the larger world in fields other than law, such as poetry, theology, and linguistics. Building on the work of others, After Revelation recognizes that medieval Jews and Muslims structured their traditions in similar ways. They inherited comparable late antique traditions (written scripture combined with oral teachings) and they layered onto them overlapping or even identical theological and hermeneutical problems. These similarities call out for comparative study. This volume accordingly follows a single, central doctrine—Oral Torah—from some of its earliest theorization in the Islamic East through its many reformulations in the Islamic West.
Drawing attention to differences in the self-depiction of medieval Rabbanites facilitates more careful cross-cultural comparisons between geographically and historically specific Jews and Muslims. Eastern Rabbanism, most shaped by Saadia ben Joseph Gaon, is marked by two primary assertions: that the revelation of Jewish law was essentially comprehensive and, therefore, that the rabbis served first and foremost as transmitters of tradition. Western Rabbanism, epitomized by Maimonides, drew the contours of revelation more narrowly, thereby making room for generative legal interpretation, at least in the hoary Jewish past.
I call attention to two overlapping factors that gave these different ideologies their shape, one theological and the other political. Jews in Iraq tended to embrace Islamic jurisprudential models that emphasized divine authority and as a result limited the ability of expert jurists to extend religious law through interpretation. While different theories of Islamic law were available to the late geonim, these individuals pieced together a pastiche of ideas that generally found divine sanction for extrascriptural practices. In part, but only in part, such claims supported institutional ones—the Baghdadi geonim were fond of announcing themselves as the true inheritors of divine tradition. (I therefore title one of the relevant chapters “From Sinai to Baghdad.”) Iberian Jewry, by contrast, flourished in an Islamic world marked by fewer varieties of Islamic law. But generally speaking, local authorities endorsed juristic extensions of the law. Rabbanites in al-Andalus also needed an approach to Jewish law that admitted their own contributions, even long after geonic authority had “ended.” They therefore depicted the rabbis as creative interpreters who were granted divine authority to extrapolate and extend received teachings.
My account centers geographic factors as the principal element in shaping Rabbanite legal theory, rather than suggesting that ideas “developed” as they moved from Baghdad to Cordoba. I also downplay polemics in explaining Rabbanite thought. Many earlier scholars have argued that Qaraite denials that God authored the rabbinic tradition led Rabbanites to assert that very claim, or more generally, that Qaraism shaped Rabbanism in highly specific ways. But Rabbanism took on many different guises from the tenth to the twelfth centuries, and therefore the Rabbanite need to polemicize, such as it was, did not automatically produce a single rhetorical tactic. The generative nature of polemics should not be gainsaid, but I see polemics as chiefly spotting weak points that needed to be defended, rather than guiding the forms that defenses of the rabbis assumed.
Jewish law must take its place alongside more familiar domains of discourses that Jews molded in dialogue with Muslim ones. Dynamics of interaction between Jews and Muslims (and others) varied across different fields. Openness in medicine or astronomy might have felt unproblematic to many medievals, and philosophical and theological notions could circulate with relative ease or even be cut-and-pasted almost seamlessly. But law is far more intramural. It usually derives authority from appeals to a specific past or textual corpus. Nonetheless, After Revelation demonstrates that legal-philosophical issues were formed in the same interconfessional kiln as many others—Jews and Muslims penned their legal theories in dialogue with their own literature, with earlier Muslim legal theorists, and with each other.
In the centuries-long inquiry into the rabbinic project, the Islamic world was a central and clarifying waystation. Arabic-speaking Jews were crucial transmitters of Rabbinic Judaism. And they employed ideas in broader circulation to make sense of the rabbis, a pattern that would be endlessly repeated.
[1] National Library of Israel, Ms. Heb. 4°577.4.83, in David Sklare, Samuel ben Ḥofni Gaon and His Cultural World: Texts and Studies (Leiden: Brill, 1996), 56 (Hebrew pagination).
Marc Herman is an assistant professor in the Department of Humanities at York University. His research focuses on Jewish and Islamic intellectual history in the medieval Mediterranean. His monograph, After Revelation: The Rabbinic Past in the Medieval Islamic World, appeared with the University of Pennsylvania Press in August 2025. Marc coedited Accounting for the Commandments in Medieval Judaism: Studies in Law, Philosophy, Pietism, and Kabbalah (Brill, 2021) and Worlds of Jewish Law: Premodern Legal Cultures in the Making (under review). Prior to joining York’s faculty, he held postdoctoral fellowships at Columbia University, Harvard University, the University of Pennsylvania, and Yale Law School. Marc’s current project reconstructs the writing, rewriting, and transmission history of Maimonides’s Sefer ha-Miṣvot.