Authors such as Ann E. Mayer define Islamic constitutionalism as "constitutionalism that is in some form based on Islamic principles, as opposed to constitutionalism that has developed in countries that happen to be Muslim but that has not been informed by distinctively Islamic principles".[34] However, the concrete meaning of the notion remains contested among Muslim as well as Western scholars. Influential thinkers like Mohammad Hashim Kamali[35] and Khaled Abou El Fadl,[36] but also younger ones like Asifa Quraishi[37] and Nadirsyah Hosen[38] combine classic Islamic law with modern constitutionalism. The constitutional changes initiated by the Arab spring movement have already brought into reality many new hybrid models of Islamic constitutionalism.[39]