a research on the concept and reliability of fixed way of religionists (irtikāz al-mutisharri‘a) as explained by shī‘a jurists’

sīra is of a sublime status in shī‘a jurisprudence and has been used as the most important reason in endorsed rulings of islam. the shī‘a jurists have used it as one of their evidences for inference of rulings to the extent that they have regarded it as superior to consensus (ijmā‘) and viewed the authority of sīra as a cause for endorsement or non-hindrance by the infallibles (a.s.). in the course of the history of inference, a new term has been developed, which in line with sīra was employed as a proof for inference of rulings and the jurists called it fixed way of religionists or irtikāz al-mutisharri‘a. it is the proof and establishment of a concept in the religionists’ mind that cannot be easily given up and sometimes it results in external conduct and behavior and yet at other times it remains to be subjective. that the jurists have relied on irtikāz in some rulings indicates that in their view irtikāz is authoritative. conceptual irtikāz is separate from sīra and it behooves to be dealt with under another heading than sīra, even though, like sīra, it is regarded as rational (lubbī) circumstantial evidence and in many instances it is the original resource for the evidences. in this research, after giving a definition of sīra and irtikāz al-mutisharri‘a and proving the conditions for their authority, it is tried to compare these two terms and to clarify their similarities and differences, and then to point out the instances that are regarded as origins for irtikāz.