Fakhr al-Dīn al-Rāzī's conception of proposition

Ibn Sīnā (d. 428/1037) dissented dramatically from his predecessors on issues such as types of modal propositions, contradiction, conversion and contraposition, categorical syllogism and modal syllogism with his understanding of absolute and modal propositions, which became evident in the centre of essentialist (ḥaqīqī) propositions and five universals. Ibn Sīnā's unique system of proposition and syllogism dominated the course of Islamic logic studies. Fakhr al-Dīn al-Rāzī (d. 606/1210), on the other hand, followed Ibn Sīnā and Avicennian logician Sahlān al-Sāwī (fl. 540/1145) in these matters, and he transformed the system which Ibn Sīnā laid the foundations into a more complete and perfect system with commentary, correction, reclassification and criticism from time to time. In this respect, it can be easily said that there are two milestones in Islamic logic, namely Ibn Sīnā and Rāzī. Consequently, the present study is structured around two main questions. The first of these questions is with which factors and how the system came into being, which was put into a final form to a large extent by Rāzī. The second question is about his exact position against Ibn Sīnā's logic in the context of propositions. This study, which aims to answer these two questions, consists of four parts. The first chapter of the study examines the nature and types of the categorical propositions, the second chapter deals with general absolute and modal categorical propositions, the third chapter examines contradiction, conversion and contraposition in categorical propositions, and the fourth and last chapter focuses on hypothetical propositions. In all parts of the study, the new forms that the problems took during the transition process from Ibn Sīnā to Rāzī, and from time to time their appearance after al-Rāzī, are examined, to obtain a holistic picture.