Differences in usul in the context of Furuq al-usul of İvaz Efendi

One of the sub-disciplines of the science of usul (methodology of fiqh) that developed over time is the type of furuq books, which deals with the subtle differences between similar cases. This study examines the differences in usul in the context of furuq al-usul of Ivaz Efendi (d. 994/1586). It aims to introduce the science of furuq al-usul in the lifht of this work. Data was collected by literature review method and their analysis and synthesis were made. The study has revealed that the differences in usul was examined in usul works in the early periods and that the independent studies started to appear from the tenth century AH. It has been found out that the independent furuq literature in the field of furu fiqh (positive law) began to emerge as early as the fourth century AH. The reason for this might have been that while the furu cases appeal to the public, usul appeal to the intellectuals, the lawyers. It has been observed that Ivaz Efendi touched upon completely opposite issues in his work. This can be explained by the fact that the work was written for educational purposes. In addition, the study has been found out that the work furuq al-usul which is attributed to Ibn Kemal Pasha (d. 940/1534), belongs to Ivaz Efendi.