Qushji's Cosmology, Saving the Phenomena instead of Making Theory about the Motion of Celestial Bodies

. Astronomers in later periods of Islamic astronomy were more influenced by Avicenna’s natural philosophy, So they used the basics of natural philosophy in astronomical theories. This prompted them to try to replace the Equant model proposed by Ptolemy with new models. Muslim astronomers and philosophers were interested in considering the spheres as material bodies and sought the cause of phenomena in philosophical discussions. But Ptolemy used his models only in explaining the universe in his book, Almagest. And his aim was not to find the cause of the motion of the planets and spheres. Astronomers' philosophical beliefs about the motion of the spheres can be seen in other topics, such as the material of the spheres, their simplicity, and the type of motion they all have. These views are due to their interest in finding the cause of the planets' motion. Ali Qushji lived in the last years of the astronomical period in Islamic civilization. He wanted to save the phenomena instead of finding the reasons for what happened. Because he was distrustful of astronomical theories. This article will address Ghoshchi's astronomical views of cosmology.