Abstract
In this article, we produced a critical edition of Abu al-Futūḥ Najm al-Dīn (Kamāl al-Dīn) Ahmad b. Muḥammad b. al-Serī b. al-Salāh’s (d. 548/1153) work named al-Shakl al-Rābiʿ min Ashkāl al-Qiyās al-Ḥamlī and examined his arguments on the fourth figure of the syllogism in the context of the work from the viewpoint of logical validity. This work is the first text that evaluated the mods of the fourth figure in classic logic. Before this paper, this work had been published a few times as photography and typewritten through used its manuscript numbered 4830 in the Süleymaniye Manuscript Library, Ayasofya Collection. However, we explored a different copy of this manuscript in the same collection numbered 4845. The former manuscript contains some deficiencies such as erased its ink. For this reason, these published versions are lacking in some expressions. So, our main aim in this article is to prepare a factual critical edition of the work.