Both Earth and Sky: The Survey of Muhammad

Abstract

Al-Risalat al-Muhammadiyya fi 'ilm al-hisab, the only known comprehensive Arabic mathematics book of 'Ali al-Qushji, was dedicated and gifted to Sultan Mehmed II by the author himself. According to the available copies, the work was reproduced for two centuries. This means that it was read and taught by experts in the field. Existing research on a general mathematics book that was in circulation for two centuries is quite insufficient. Considering this deficiency together with the knowledge that the author was a polymath, research in each field in which he wrote becomes more important in order to see the whole. In view of this, the subject of this article has been chosen as the chapter on al-masaha of the al-Muhammadiyya. This is because the content of this chapter points to both the author's astronomical and linguistic orientations. However, in order to determine the position of the chapter on al-misaha, it is first necessary to see its place in the whole book. For this purpose, firstly, the general content of the book is given and then the position of the chapter on al-misaha compared to other chapters and its classification within itself are discussed. The detailed content of the chapter and the features of this content that differ from the al-misaha chapters of the mathematical books of its predecessors are given, and the main purpose of the article is realised by drawing attention to their possible relations with astronomy and language studies. As a result, it has been determined that Ali Qushji took a different position from his predecessors and contemporaries in terms of (i) the classification of general mathematical books, (ii) the place where he positioned al-misaha, (iii) the points of emphasis in the content of al-misaha, (iv) the definitions of the concepts of al-masaha, and (v) the fields related to al-misaha.