An Inter-religious Study of the Position of the Two Main Schools of Thought on the Scope of Authority of the Sunnah

The Sunnah is the second source of Islamic law and the most important source that can be used, after the Glorious Qurʾān, to formulate an Islamic model of social sciences. This imperative task can only be carried out when the meaning and scope of the authority of the Sunnah is established. The present article seeks to review the opinions of scholars of both [the Shīʿa and Sunni] schools of thought in Islam about the scope of authority of the Sunnah, and to critique and evaluate them from the perspective of the Holy Qurʾān and the traditions of the infallibles (a), in order to arrive at the actual scope of this phenomenon.
From the conclusion of this study it can be seen that among the traditional and reformist views put forward about this issue, the rational and scriptural bases of the claim that the scope and authority of the Sunnah is limited are, for several certain and definitive reasons, unsound and invalid. In addition, the Holy Qurʾān and traditions of the infallibles (a) establish the unrestricted scope of authority of the Sunnah without any distinction between worldly and non-worldly matters, ordinary and extraordinary affairs etc. Therefore, the scope of authority of the Sunnah is absolute and this valuable resource can be used as a reliable source for the formulation of Islamic social sciences.