Among the three arguments to demonstrate the existence of God, I find Thomas Aquinas's cosmological argument well founded on empirical evidence and that the focus on simple facts proves to be acceptable in both the historical and scientific dimensions. Aquinas begins by stating the preliminary point that the existence of God is not evident, and therefore we must examine the effects of God, which we are able to observe, to prove the existence of God , even if we are unable to perfectly understand the nature of God. Aquinas provides five ways to demonstrate the existence of a transcendent being through empirical evidence. The Argument from Motion, the Argument from the Nature of Efficient Causes, the Argument from Possibility and Necessity, and the Ex Gradibus Argument each use simple, observable facts to demonstrate the existence of God as the prime mover, ultimate cause, being necessary and a final degree; the design argument employs the teleological approach and demonstrates the existence of God as a designer by exploring the more complicated nature of things. Thomas's discussion of the preliminary question is essential to understanding his five proofs. The dependence of his argument on empirical evidence contrasts with the a priori ontological argument. Rowe, in his critique of the ontological argument, argues that "from the logical analysis of a certain idea or concept we can never determine that there actually exists something corresponding to that idea or concept" (P.108). Aquinas also recognizes the lack of an a priori argument. While Anselm, in his Proslogion, maintains that "one cannot think that God does not exist" (p.71), Thomas points out that "one can mentally admit the opposite of the proposition God is: ....Therefore, that God exists is not evident." (P......middle of paper......efficient reason that "there is some sort of explanation, known or unknown, for everything" (P.148). The impulse to explaining a seemingly obvious fact, whether motion or existence, lies at the heart of Aquinas's cosmological argument. Rowe states, however, that "we do not know that the PSR is true" (P.168); ontological dependence on a transcendent cause" (P. 142) is somehow mystical, then Rowe's suggestion that there may be something in the world that does not require explanation is truly unscientific, because it is human nature to seek explanations for facts in the world, and such constant desire and effort, reflected in myths, religions, arts and sciences, have guided human society from its primitive form to the sophisticated world of today, and will continue to stimulate the creativity of humanity so that it flourishes according to the transcendent laws of nature.