Foundation for Iranian Studies

The article deals with the personality of a Muslim scholar of the 1st part 14th cent. His name was `Ubayd Allah b. Mas`ud, his laqab was Sadr ash-Shari`a as-saghir (Sadr ash=Shari`a ath-thani). He authored a work (yet unpublished) known under the title Ta`dil al-`ulum, which until recently has not attracted sufficient attention. The article comprises `Ubayd Allah b. Mas`ud’s biography and a survey of the existent hand-written copies of Ta`dil al-`ulum. Dr Idrisov suggests a different date of its composition and offers some corrections to the existent MSS catalogues where the work is described. Along with this information the article provides a survey of the sources used for compiling the Ta`dil al-`Ulum as well as a summary of the work, which became a milestone in the development of the maturidi kalam in Khorasan and Mawarannahr.