Historical Background of Obligatory Preliminary (Moghadamaye Vajib) in Islamic Jurisprudence

Explaining some Islamic theological opinions gives rise to the subject of Obligatory Preliminary (Moghadamaye Vajib) to enter into Usul Fiqh in 5th century. Jurists with resort to legal opinions in earlier centuries try to analyze legal propositions which is consisted of Obligations and their Preliminaries and Prerequisites. The result of this analysis was distinction between various kinds of preliminaries and matters like "prerequisite" and "Cause". Despite the fact that different ideas about Moghadamaye Vajib existed among jurists, both Sunni and Imami, development of this matter is owed to Imami scholars efforts. This development was to the extent that its application in Fiqh caused doubt and some considered it as a useless subject. This essay with a historical method, attemmts to regulate the development of this matter in Islamic Jurisprudence. Finally, some legal opinions in earlier, middle and recent period is chosen to illustrate the application of this matter in analyzing personal and social problems in Fiqh.