The Application of Istishāb (Presumption of Continuity) in Time-bound Matters

Different views have been expressed with regards to application of Istishāb (lit. presumption of continuity) in temporal or time-bound matters. According to all scholars of Usul (legal theory), and also rationally and philosophically speaking when a meticulous study is conducted, Istishāb is not applicable to time bound matters. Thus, a given doubted subject-matter cannot be presumed as having remained because it does not have previous state to be supposed. Likewise, Istishāb kulli or general presumption of continuity also does not apply because the general existence of something which was taken as a part of a previous individual object has ceased to exist and the same general entity as a part of a succeeding object was doubted in the first place because it is not known for sure whether or not it occurred. Additionally, the basic components of incomplete presumption of continuity do not exist nor is there unison between a definite and certified premise and a doubted one. According to a conventional musamaha (overlooking), despite differences of opinion, most of the scholars of Usul are of the view that the presumption of continuity can be applicable to time-bound matters. That is because, in the eye of custom ('urf), the certainty has been affected by the ensuing doubt, although there are differences in common view. Some have, in an absolute way others in a particular case, considered customary ('urfi) unity as a criterion. In any case, there is nothing to bar the application of Istishāb because certainty exists as a previous mode and the ensuing doubt is also there. Moreover, the purport of "do not break your certainty with a doubt" is true with gradual matters.