Constitutionalism and the Concept of Law in Mirza Naini’s Political Thought

The concept of “law” should be considered as the epicenter of constitutionalism in Iran. Therefore, basic conflicts emerged between Sharia and the modern law, and divided cler-gymen into two spectrums, Constitutionalists and Traditionalist (Sharia), which the promi-nent representative of constitutionalist spectrum was Mirza Mohammad Hossein Naini. Based on his ideas and Ijtihad’s (exegesis of divine law), for resolving the conflicts about setting Constitutional Government, we found that, Naini considered Constitutional Gov-ernment as the best political system in the age of Imam’s absence (occultation), based on nation’s will through the parliament, and by dividing the Sharia law in two groups of "Man-soos" (based on Quran and Hadith) and "Gheyre Mansoos" (not based on Quran and Ha-dith), put the concept of law in the realm of Gheyre Mansoos laws which could be passed and enforced by nation’s representatives in parliament. In this article with the analytical me-thod and by citation of historical written texts, this issue is clarified.