Debates about the validity of legal pluralism in legal theory

The earliest sources of Islamic law show a contested view toward juristic disagreement and its concomitant legal pluralism. To al-Shafi'i (d. 204/820), such pluralism is to be expected as part of the process of ijtihad, exerting one’s effort and reflection to reach a legal rule.

In the late eighth and ninth centuries, a group of Mu'tazilis did not allow for any prob­ability in law, presuming that legal evidence should always be apodictic. These proponents of legal certitude included the Zahiris, Shi'is and Mu'tazili theologians such as al-Asamm (d. 202/816) and al-Marisi (d. 218/833). In Sunni Islamic law, this group, which rejected legal pluralism outright, eventually died out. Almost simultaneously, traditionalists, who put forward an agenda centred on purifying Islamic law from non-Islamic influences by focusing on Prophetic reports, criticized juristic disagreements. In their estimation, such disagreements were largely the result of the extensive utilization of ‘personal reasoning’ (ra'y), a form of ‘practical reason’ used to deal with questions unaddressed by the Qur’an. The traditionalists, who were fallibilists (more on this in the following paragraphs), argued that if jurists abstained from using non-textual sources such as human reasoning, including analogical reasoning, there would be few juristic disagreements and therefore less space for legal pluralism.¹⁴

After al-Shafi'i’s time, jurists operating in the tenth to the thirteenth centuries, drew a distinction between rules whose proofs are apodictic, for which there is only one correct mujtahid and one truth, and rules that are based on non-apodictic evidence, wherein there was much disagreement among legal theorists.

Within the fallibilist position, there were different approaches to the scope of legal issues that are unknowable. For some, the scope of legal issues over which there is only probable

knowledge was expanded to include practically all actual areas of disagreement among the four Sunni schools. In other words, even though there is only one truth in the mind of God, this truth cannot be known with certainty to us humans, and therefore, this position closely resembles the multiplicity of truth doctrine in that it valorizes legal pluralism, equating it with actual juristic disagreements.

Other fallibilists narrowed the scope of such points of law that are unknowable to a min­imum due to their legal methodology, which assumed that many of the opinions of jurists were simply incorrect. According to them, truth was indeed knowable in the majority of cases of actual disagreement, opining that many juristic disagreements are not justified. This camp includes jurists such as the Zahiri Ibn Hazm (d.

In the course of the systematization of the debate over the ontology of legal truth in the tenth to the 13th centuries — a process partly driven by the dominance of Ash'ari theology — al-Shafi'i’s heritage was claimed by fallibilists and infalliblists, with both sides projecting their own contradictory positions onto their eponym. By contrast, most jurists counted Abu Hanifa, Abu Yusuf and al-Shaybani among the infalliblists.¹⁶