Abstract

To indicate the opinions of these two philosophers on the demonstration of the necessity andpossibility, the author has studied the issue of the possibility of cognition from Sadr-al-Mutaallihins point of view, and comparing it with that of Paul Thillich, notes what they have in common and their distinctions.Emphasizing on the importance of the rational demonstrations and intuitions in Sadrean school, which are not inconsistent in this school, the author provides an account of Thillich's point of view with a critical approach. According to this point of view this demonstration, like the other philosophical demonstrations, confirms only that there is a question about God whose answer is God who appears in man's conscience through observing the world. Surprisingly enough, according to Thillich, proving God through the demonstration of necessity and possibility is same as denying Him.