Rethinking the nature of authorization of previous state (istishab) with a look at the theories of Professor Jafari Langroudi

istishab is one of the useful documents in deriving jurisprudential rulings and legal arguments. istishab is briefly defined as legal presumption of continuity of the status quo in doubtful case. The conditions, elements, and types of istishab have been studied with the great efforts and scrutiny of Islamic scholars. The conditions, elements, and types of istishab have been studied with the close look of Islamic scholars. These researches have caused the use of istishab to expand tremendously in the field of jurisprudence, rules of it and law. But the "essence and nature" of istishab remains an important and fundamental question. In this research, while examining the literary and terminological meaning of istishab and trying to apply this meaning, to the evolution of practical principles - in general - and istishab. Although the word istishab is not mentioned in the tradition, but its content is included. Perhaps the first conceptual argument for acceptance is for Hisham ibn al-Hakam, who lived before Imam al-Shafi'i. In historical examining of the rules of jurisprudence, we come across terms such as "istishab of the present", "istishab of the state of reason" in the jurisprudence of the predecessors, which is clearly different from the current "istishab" in the rules of jurisprudence. First, the brief difference between the presumption and the practical principle is explained and the the opinions of Islamic jurisprudents are mentioned in order to determine the statistic and the practical principle of istishab. Some later jurists have proposed a theory called the "discounted and establishing principle" such as Mirza Naeini to be a new solution to the dual answer of "being a persumption" and being a "practical principle" of istishab. Regardless of this solution, accurate analysis of the problem solution requires the study of indicators and criteria for solving the problem, For example, the validity of istishab or the analysis of its elements has a clear effect on solving the problem of "being a presumption" and being a "practical principle" of istishab. In the end, while exploring the principles of istishab in the opinions of prof.Jafari Langroudi, as a summary, it is expressed three intellectual, jurisprudential and integrated source of istishab.