Clarifying the concept of criteria and related topics and examining the various ways of discovering criteria are highly important and critical to jurisprudence and legal theories, and there are many difficulties in this area which require a lot of research and in-depth study.
There are subtleties and precise points in the discussion concerning the methods of discovering criteria (kashf milāk) such as the consistency of the norm (ḥukm) and the subject (mawḍūʿ), clarification of the criterion, termination of the specifics, the taste of the Sharīʿa, as well as analogy (qiās), istiḥsān (preferential reasoning), the purposes of the Sharīʿa, the public interest, and the like, based on the legal and theoretical school of Ahl al-Sunnah which have been studied and researched by Shiite scholars but this much of scientific research is inadequate.
This article deals with only one of the ways to discover the criteria based on Mirzā Nāʾīnī 's point of view, and that is to discover the criteria by way of the fact that Hadith Rafʿ is intended to remove certain obligations out of gratitude. Although Allāma Nāʾīnī's discussion is detailed and thorough, some criticisms have been made on his viewpoints in this article after stating two rapprochements to argue his claim.