The Principle of the Presumption of Continuity (Istiṣḥāb): A Comparative Study of Its Formation, Evolution, and Scope of Application in the Principles of Jurisprudence in Islamic Sects

In Islamic legal theory (uṣūl al-fiqh), various principles assist a jurist in deriving Islamic laws from their sources. One such principle is ‘‘the principle of the presumption of continuity,’’ (istiṣḥāb). This article discusses istiṣḥāb in the course of the historical development of Islamic legal theory among Sunni and Shīa schools of thought. After reviewing the early sources of Sunni and Shīa scholars on legal theory, this article investigates the constructive contribution of Shīa and Sunni works concerning the formation and evolution of istiṣḥāb; an attempt which may, in part, serve to resolve the Shīa – Sunni quarrel about the formation and evolution of Islamic legal theory as a whole. This study concludes by acknowledging the Sunni scholars’ role in the invention of istiṣḥāb, followed by the stagnation era, and on the contrary, the adoption and development of istiṣḥāb among Shīas.