An Inquiry into the «Demonstration of Necessity and Possibility» in Western Philosophy with Emphasis on Thomas Aquinas's Exposition

The question of the existence of Allah has long been a source of interest to philosophers who have made tremendous efforts in this regard and came up with many demonstrations. Farabi has presented the demonstration of "necessity and possibility", which is considered among the strongest evidence on the existence of God.
After Farabi, other especially Muslim philosophers, philosophers, presented differing views about it. Ibn Sina`s demonstration is one of the earlier and most well-known expositions of the evidence on the existence of God. Using an analytical-theoretical approach, this paper analyzes Ibn Sina`s demonstration of necessity and possibility and examines the works of western scholars who consider the mentioned demonstration as a cosmological evidence. Aquinas`s exposition is among the most famous expositions of this demonstration in the West. This study reviews this demonstration from the viewpoint of Aquinas, and comments on it.