This paper investigates the constitutional moment of the Young Turk revolution of 1908 and analyzes Islamic discourse on constitutionalism. It demonstrates the rich legacy of the Ottoman experiment in equal citizenship for all, regardless of ethno-religious background. The setbacks and failures of this moment in the late Ottoman Empire should not lead us to underestimate the merits of this historical case, which could still provide relevant perspectives on the Muslim rule of law in the contemporary world. In this regard, this research examines the constitutionalist thought of three illustrative and critical figures in late Ottoman religious politics: Shaykh al-Islam Musa Kazım Efendi (1858-1920), Said Halim Pasha (1865-1921), and Bediüzzaman Said Nursi (1878-1960). This study allows them to speak for themselves regarding the relationship between constitutionalism and Islam, moving beyond the previous Orientalist and dichotomous historiography. I argue that the Ottoman intelligentsia developed a synthesis between Western concepts of constitutionalism and traditional Islamic governance through diverse approaches and arguments. The Second Constitutional period is a significant historical framework for state-religion relations in the Modern Middle East because it allowed secular law-making within the purview of Islamic law through the application of the "sharīʿa-oriented policy" (al-siyāsa al-sharʿiyya). This was the first period of Islamic constitutionalism in the Middle East before the emergence of Islamist ideologies in the second half of the 20th century. In this period, the Ottoman Islamic constitutional framework was based on the limitation of legislation by Islamic jurisprudence, whereas post-War Islamist ideologies considered "Islamic law" as the basis of legislation. Keywords: Ottoman Constitutionalism, Equal Citizenship, Rule of Law, Legal and Political Equality, Musa Kazim Efendi, Said Nursi, Said Halim Pasha