Question of relation between an essence and an existence was one of major medieval philosophical problems. The first ones who started considerate this issue were Muslim thinkers, especially Avicenna and Averroes. The latter of them was one of the main figure in this debate. Étienne Gilson claims that on ground of Averroes’ thought Aristotle struggles with problem of existence. Averroes claimed that this two components differ only in logical manner. In reality an essence and an existence are identical and an existence is something which flows from essence of being. That is why Averroes did not agree with Avicenna that existence is only a accident of essence, because such claim is contradictory with Aristotle’s theory of being. According to ...