Theoretical and practical inconsistency in the use of rejected hadiths in Islamic law

In Islamic history, following the demise of the Prophet Muhammad (peace be upon him), particularly during the caliphate of ʿAlī ibn Abī Ṭālib, internal discord and divisions within the Muslim community led to the emergence of fabricated hadiths. These conflicts gave rise to disputes in political, theological, and jurisprudential matters. Consequently, efforts to develop methodologies for obtaining reliable and authentic reports gained importance, and certain principles were established concerning the use of hadiths in these areas. This study aims to identify those principles and examine whether Islamic jurists adhered to them. In cases where they did not, the study explores the underlying reasons for such flexibility or deviation. The research is composed of an introduction and two main chapters. The introduction outlines the subject, purpose, and sources of the study. The first chapter discusses the foundational concepts related to the research, such as Sunnah and Hadith, mutawātir and āḥād, maqbūl (accepted) and mardūd (rejected) reports, yaqīn (certainty) and ẓann (conjecture), as well as fiqh and aḥkām (legal rulings). The second chapter examines the necessity of using only acceptable hadiths in Islamic law, the obligation to clarify the weakness of a hadith, the prohibition of acting upon or transmitting fabricated reports without warning, and the scholarly views on the use of weak and fabricated hadiths within the context of fiqh. As a result of the study, it has been determined that although scholars have stated that weak hadiths should not be acted upon in matters of creed, legal rulings, or ethics, in practice, they have nevertheless utilized weak hadiths in all these areas.