The comparison of the theory of " the difference between existential truths" in peripatetic philosophy with the theory of " the unity of the truth of existence and The differences of its levels" in the transcendental wisdom

Mulla Sadra has claimed in some of his writings that there is no difference between the unity of the existence and the difference of it in the transcendentalist wisdom, with the theory of difference of existential truths in the peripatetic philosophy. The present article aims to investigate and explain this claim by analytical-critical method. the Mashayyans have counted three type distinctions: the distinction to all nature, the distinction in nature and the distinction between the effects of nature, that the difference between existential can not be placed in either of these three categories. Hence, in order to explain the difference between existential, we go to the fourth type of distinction, namely, gradation of distinction. Ibn Sina has revoked gradation of nature and has not explicitly discussed about gradation of existence. But his points to topics such as the Severity and weakness of existence and the Principle of causation, suggest that, in order to explain the difference between existential, one can attribute a gradation of existence to Ibn Sina. Therefore, it can be said that Mulla Sadra's claim that there is no discrepancy between the theory of the difference between existential of the Mashayyans and his theory, namely, the unity of the existence and The difference of it (gradation of existence), is a correct claim, but It can be said that this is the same between these two theories.