Determines the modern subject ontology, which manifests itself through cartesian design, through a negative distinction. Accordingly, in the soul-body dichotomy, the body is seen as a mere diffusion and has a secondary status, while the soul is identified with the mind. In this respect, the modern subject distinguishes itself from the mind, which it accepts as unchanging, unrestrained and universal in nature. The desire to establish a subject that is complete, complete and can dominate all existing ones becomes evident in such an understanding. With the Cartesian design, the whole of the ontic world is reduced to the designs of the subject; the world of knowledge overrides the world of the existing. In this respect, the first distinction made on the ontological plane for the Cartesian subject, which does not have the possibility of existence without the act of boundary and successive exclusion that reveals the dualities, emerges through reason and irrationality. Because while the existence of the soul is considered as mind; "I" exists only through the act of thinking. The main argument of our study is that “modernity identifies irrationality with being non-human and deems as an ontological problem by reducing human beings to mind”.