Isbat al-wajib (Proving god's existence) according to Shahristani

The isbât al-wajib issue has always maintained its importance throughout human history. The kalamists and Islamic philosophers have tried to prove the existence and unity of Allah with many different proofs. Shahristani also contributed to the world of Islamic thought with logical and philosophical explanations by suggesting different proofs on this subject. Shahristani has an important place in the history of Islamic thought. Besides the religious sciences, especially the Kalam, Tafsir, history of religions and sects, he is also famous for his studies and works in the field of Philosophy. He lived in important science centers of the Horsan region in the VI/XII century. He is the foremost representative of the muta'akhirin era, which began with Gazzali. In general, he revealed his ideas in relation to the Ash'ari Kalam school. Shahristani, although he had copyrighted works in different fields, he was also interested in the sciences of logic and philosophy as of his time and published works in these fields. In his works, he studied the issues that have been controversial in Islamic thought, and especially the basic principles of religion, and used rational and philosophical methods with an argumentative style. This thesis consists of an introduction and two parts. In the introduction section, information about the subject, purpose and importance of the research, the methods and scope of the research, the emergence of the issue of isbât al-wajib and the life of Shahristani, his scientific personality and works are given. In the first chapter, the views of the kalamists and philosophers on the issue of isbât al-wajib and the basic evidence they put forward on this issue are given. In the second and final section, which constitutes the center of our study, the approach of Shahristani to the isbât al-wajib issue and the evidences used in this framework are tried to be put forward. The scope of our research is limited by the presentation of his views on the subject, based on his works entitled Nihayat al-Aqdam fi 'ilm al-Kalâm and Kitâb Musaraat al-Falasifa, which are related to Shahristani and which deal with the isbât al-wajib issue in general. Although descriptive and analysis-synthesis are the main method of study, comparison method is also used when needed. As a result, the thesis was intended and studied to present Shahristani's views on the existence and unity of God as a whole. Key Words : Kalam, Shahristani, Theology, Isbat al-Wajib, Proofs.