Correspondence, Constructivism, and Representation: Variant Approaches to Astronomical Knowledge in Islamic Legal Texts

The story of astronomy's relationship to Islamic law has often been told in terms of a disjunction: astronomers developed sophisticated techniques capable of being employed for purposes of ritual, but which jurists disregarded in favor of "folk" methods. Though this characterization remains a fair one in broad strokes, delving into the fiqh literature at its margins provides an important view into variant approaches to evidence, revealing in turn the pliancy and malleability of even the most historically unshakeable evidentiary regimes. Though the Sunni madhhabs (juristic schools), the sophisticated apparatuses of canonical authority that governed Islamic legal thought and practice for centuries, clearly delineated dominant positions that constituted the school doctrine on a given issue, they also functioned as sites of reasoning, discourse, and intellectual heritage that provided for creative and opportunistic departures from the doctrine. The question of making use of astronomical calculations to determine the months of the hijri calendar is a particularly resilient example of the fiqh's tendency to set aside the findings of astronomers for ritual purposes. Nevertheless, this regime did not stamp out the existence and periodic assertion of positions that were friendlier to calculations, alternatives that were able to exploit pressure points in the edifice of the juristic school to allow for complicated and variant understandings of the evidence. These positions were framed not as direct contradictions of school doctrine, but as negotiations with it that made greater room for the role of astronomers within the law. Key to their mode of argumentation, then, is that the master regime structured the nature of the departure. Equally importantly, these variant opinions were interlinked, with later attempts at asserting calculations relying heavily on earlier efforts, recruiting their authority to push the argumentation further or in new directions. Taken together, this sequence of interventions constituted a minoritarian trend within the corpus of fiqh.

Focusing on the trajectory of this minoritarian trend in the Hanafi and Shafi'i schools, I consider three particular approaches toward astronomy in Islamic legal writing that made room for calculations—what I call correspondence, constructivism, and representation—to demonstrate that the long-standing and far-reaching tradition of discourse and debate that is fiqh does not offer a singular approach to astronomical evidence, but rather encompasses a range of attitudes.

Rather than read the interaction between astronomy and law as a species of the primordial contest between reason and revelation, a more nuanced view is appropriate for the fiqh literature. Shifting away from the assumption that religious texts ought to be understood as being in competition with, or inimical to, science allows us to envision a given nass (text) as simply one piece of evidence among others (e.g., data points obtained through perception, calculation, or cognition) to be grappled with and understood within a constellation of factors constituting a holistic regime of evidence. A revelatory text, though it may override other considerations, is not a closing of an argument, but rather should be thought of as folding into a larger context of understanding in which the demand to address rival evidences is perhaps the most central interpretive challenge. This is a task that has long been familiar to Muslim jurists who wrote at length about resolving conflicting textual indicants (ta'arud al-adilla),¹ making room for local custom ('urf, 'ada),² accounting for social welfare (maslaha),³ specifying the appropriate role for juristic discretion and considerations of equity (istihsan), and, as we will see, weighing the respective demands of empirical observation and textual hermeneutics. Indeed, envisioning the jurist's duty as preferring (tarjih) some evidentiary considerations over others, or ideally finding a way to reconcile them (jam', tawfiq), is a helpful model for understanding much of the jurisprudential literature.⁴

The Dual Nature of Astronomy in the Service of Islamic Ritual

In an influential article, the historian of Islamic science David King has pointed out three key areas in which astronomy was used "in the service of Islam."⁵ These were the regulation of the lunar calendar, the specification of the times for the five daily prayers, and the determination of...