The aim of this thesis is to comprehensively survey and evaluate scholarship, from Ibn Khaldun (1332-1406) to the present, on the fate of Islamic science between the eleventh and sixteenth-centuries, and to outline a more adequate scholarly approach. The thesis also assesses the logic and empirical accuracy of the accepted decline theory, and other alternative views, regarding the fate of Islamic science, and investigates the procedural and social physiological factors that give rise to inadequacies in the scholarship under question. It also attempts to construct an intellectual model for the fate of Islamic science, one that examines the cultural environment, and the interactions among different cultural dynamics at work. Drawing upon Ibn Khaldun's theory and recent substantial evidence from the history of Islamic science, this thesis also entails justifying the claim that, contrary to common assumptions, different fates awaited Islamic science, in different areas, and at different times. For the period of Ibn Khaldun to the present, this thesis presents the first comprehensive review of both classical and contemporary scholarship, exclusively or partially, devoted to the fate of Islamic science for the period under study. Based on this review, the thesis demonstrates that, although the idea that Islamic science declined after the eleventh century has gained a wide currency, and may have been established as the preferred scholarly paradigm, there is no agreement amongst scholars regarding what actually happened. In fact, the lexicon of scholarship that describes the fate of Islamic science includes such terms as: "decline," "decadence," "stagnation," "fragmentation," "standstill," and that Islamic science "froze," to name just a few. More importantly, the study shows that six centuries ago, the Muslim historian Ibn Khaldun provided a more sophisticated and complex theory regarding what happened to Islamic science, which was not utilised except in the work of two scholars. The thesis tests the adequacy of the different claims by applying them to four case studies from the history of Islamic science, and demonstrate that evidence for specified areas shows that different fates awaited Islamic science in different areas and times. In view of the fact that Ibn Khaldun's theory is six centuries old, and that evidence of original scientific activity beyond the eleventh century emerged in the 1950s, what would one expect the state of scholarship to be? One would expect that with the availability of such evidence the usage of "decline" and other single-faceted terms would begin to disappear from the lexicon of scholarship; scholars would show awareness, and criticism, of each other's work; and development of more and more sophisticated concepts would emerge that would explain the fate of Islamic science. The thesis demonstrates that this did not happen. It argues that the key problem is that, after Ibn Khaldun, there was a centuries-long gap, in which even excellent historians used simple, dismissive terms and concepts defined by a limited, but highly persistent, bundle of interpretative views with a dominant theme of decline. These persistent themes within the scholarship by which Islamic science is constructed and represented were deeply embedded in many scholarly works. In addition, many scholars failed to build on the work of others; they ignored major pieces of evidence; and, in most cases, they were not trying to discern what happened to Islamic science but were referring to the subject as part of another project. Thus, in this corpus of scholarship, one that contains the work of some of the 'best' scholars, the myth of the decline remains not only intact but also powerful. Convinced of its merit, scholars passed it on and vouched for it, failing to distinguish facts from decisions based on consensus, emotion, or tradition. There are very few noteworthy cases where Islamic science is being represented in ways that do not imply negativity. There are also some few narratives that present more complex descriptions; however, even Ibn Khaldun's complex theory, which is arguably the most adequate in the scholarship, is non-comprehensive. Some modern scholars, like Saliba and Sabra, present a challenge to the common argument that Islamic science suffered a uniform decline. However, in the absence of any significant challenges to the common claims of the fate of Islamic science, particularly that of decline, it is evident that, at the very least, the scholarship seems to offer support to the work of discourses that construct the fate of Islamic science in single-faceted, simplistic and reductive terms.

Fakhr al-Din al-Razi is a significant philosopher who is famous for his critics on Avicenna. He also made effective dialogues between two rival doctrines (namely Kalam and Peripateticism) in the Islamic world in Middle Ages. He defended Kalam Atomism in last decades of his life. This thesis is working on his two treatises as manuscripts and translating it into English. One of the treatises is about proving atom and another one is rejecting Hylomorphism. These two treatises are attached together as a manuscript book titled as Proving Atomism. / Au Moyen Âge, dans le monde islamique, il y avait deux groupes d'érudits qui avaient deux indications différentes sur l'existence. Le premier groupe était des philosophes, ḥukamā, qui ont approuvé falsafah ou ḥikmah. Cette doctrine avait des bases aristotéliciennes. Un autre groupe était des théologiens, mutikalimūn qui était pour la plupart atomistes. Les théologiens constituaient le kalām qui se traduisait parfois par théologie islamique.Fakhr-e-Razi ou Fakhr al-Din al-Razi était un philosophe et théologien important au 12ème siècle qui a fait des dialogues et des débats entre ces deux doctrines. Il a écrit des critiques sur les livres d'Avicenne et a défendu la doctrine de l'atomisme de Kalam. Bien qu'il ait défendu l'atomisme de Kalam dans beaucoup de livres, il a écrit un traité indépendant sur ce sujet. Cette thèse est l'édition et la traduction d'un livre manuscrit qui comprend deux traités indépendants, dont l'un, prouve atomisme et un autre réfute Hylémorphisme.Cette thèse inclut des commentaires sur l'atomisme et l'hylémorphisme (l'introduction du livre). L'atomisme comme vue générale et l'atomisme de Kalam en particulier sont étudiés. L'histoire de l'atomisme est brièvement passée en revue en tant que racines de l'atomisme de Kalam. Puis la vue de Razi sur l'atomisme est étudiée selon ce livre présent et ses autres livres. Le contraste entre la vision de Razi et la doctrine d'Avicenne comme son rival sont également analysés.