The article focuses on the role of comparative law in the field of Islamic law studies. By analyzing the historical development of Islamic law, the Author highlights a need for a definitional approach that more aptly takes into account Islamic law as a legal subject. The investigation of the concepts of sharī'a, fiqh, iǧtihād and qānun allows for Islamic law and the law of Islamic countries to be studied from a dynamic perspective. This investigation also has the ultimate aim of proposing a definition of "Islamic law".