Ontological Bases of the Universe in Plato’s and Aristotle’s Cosmologies

We firstly find traces of systematical and comprehensive thought related to existence of the universe in Plato and Aristotle. Plato, by the doctrine of ideas which is the basis of his whole philosophy, accepted that the objective world was to be composed of shadows, and he propounded that the essential was in ideal world. On the contrary, Aristotle has shaped his thoughts related to being by conception made individual substances as base, and he defended that Platonic idealism was only a conceptual structure and the truth was not composed of absolute forms or ideas but it was to be consist of indivisible unity of them. In this paper it will briefly be dealt with the bases of both conceptions.