Everything has two aspects; existential and essential or existence and essence. Now the important question is: is it the existential or essential aspect of a thing that makes it real and objective? Which one is primary causing something to be objective and which one is secondary simply qualifying or modifying it? Though there are different opinions concerning Suhrawardi’s thoery, Suhrawardi’s words show that he believes in the primacy of essence in all existents including Allah. According to him, existence is an unreal and a purely mentally-considered aspect of existents. Following an analytical method, this article aims at finding a commonality among illuminationist philosophy, peripatetic philosophy and transcendental philosophy. According to this article, illuminitionist philosophical principles are too weak to pave the way for establishing a strong philosophical system