Original Theoretical Contribution to the Problem of Stare Decisis in Islamic Law: Precedent, Authority and Ijtihad in Nigerian Sharia Courts

The common law doctrine of stare decisis (binding precedent) operates within the secular Nigerian court hierarchy, including when those courts hear appeals from Sharia decisions, but its application within the Sharia court system itself is theoretically contested because Islamic jurisprudence does not formally recognise binding judicial precedent as a source of law, privileging instead the opinions of qualified scholars and the consensus of the Ummah. This study makes an original theoretical contribution to the problem of precedent in Islamic law by examining the theoretical basis and institutional practice of precedent in Nigerian Sharia courts. A theoretical and empirical methodology is applied. The theoretical phase examines the classical Islamic doctrines of Qaul al-Qadi (judicial opinion), Ijma' (scholarly consensus), and the distinction between binding authority and persuasive precedent within Islamic jurisprudence, engaging with scholarship from Hallaq, Masud, and Calder. The empirical phase analyses seventy Sharia court decisions from Kano, Zamfara, and Sokoto from 2000 to 2023, coding the frequency and type of prior decision citation, the distinction between same-court and appellate-level citation, and the explicit or implicit operation of precedential reasoning. The original theoretical contribution is a Theory of Qada'i Salah (judicial correctness) as an Islamic functional equivalent of stare decisis, identifying how institutional authority and persuasive quality together determine the precedential weight of Sharia judicial decisions within a functioning court hierarchy. Keywords: stare decisis, Islamic law, precedent, Nigerian Sharia courts, jurisprudence.