One of the most important aspects of classical kalām is that the topics related to physics and cosmology, namely daqīq al-kalām, have an important place in it. e reason why the mutakallimūn deal with these kind of issues is commonly regarded as an effort to defend Islamic belief against other religions and ideas. On the other hand, the relationship between kalām and physical sciences is not a single-sided one in which theology completely governed physical theories. In the long run, physical theories, such as atomism, started to affect the theological ideas of the mutakallimūn and in the end kalām gained its distinct character, based on physics and cosmology. In this article, I will try to present the place and role of physical topics, namely daqīq al-kalām in classical kalām. Firstly, I will show how classical mutakallimūn divided kalām into two parts, namely jalīl al-kalām, which is related to the theological problems, and daqīq al-kalām, which is related to the cosmological problems. Secondly, I will examine to what extent mutakallimūn dealt with physical science and what kind of topics were mostly discussed in the daqīq al-kalām. Finally, how physical theories, in turn, influenced the theological side of kalām, namely jalīl al-kalām, will be discussed.