For as math, which is reasoning something
For centuries, many scholarsstrove in developing arguments that would either support God’s existence orrefute it. Both Anselm and Aquinas were among those who desired to prove God’sexistence, just in different ways. These two scholars are known as scholastictheologian, meaning they did not only believe in theology as a science, but thequeen of sciences. In this thinking, the Bible and the church fathers areconsidered as the “data”, which once gets added to Aristotle’s logic theyresult in certainty, or science. For Anselm, he attempts to prove God using apriori reasoning such as math, which is reasoning something out for a factprior to any experience or data collection and therefore it concludes that God’sexistence is self-evident. On the contrary, Aquinas attempts to prove God usinga posteriori reasoning such as science, which is reasoning something out for afact through deduction of observing the world and collecting data and thereforeit concludes that God’s existence is not self-evident.
In addition, one couldthink of a priori reasoning being advantageous over a posteriori since ityields more “certain” knowledge than the probabilistic reasoning of science. Asa result, if we want to prove God without any uncertainty, we would choose tofollow Anselm’s a priori reasoning. Anselm strove to develop a single argumentthat proves God’s existence beyond the shadow of the doubt.
In the secondchapter of the Proslogion page 87, he advocates the “ontological argument” forthe existence of God. Anselm states, “We believe that you are that thing thanwhich nothing greater can be thought.” Therefore, according to Anselm, the foolwho says in his heart “There is no God” is contradicting himself by simply thinkingof such a God because Anselm believes that such an idea cannot reside exclusivelyin the understanding. Furthermore, Anselm makes a distinction betweenunderstanding something and understanding that it actually exists.
Therefore,the fool must concede that since he is aware of such a perfect being in hisunderstanding, such a perfect being exists in reality: “For if it exists onlyin the understanding, it is possible to think of it existing also in reality,and that is greater.” However, although Anselm argument works in the sense thatit proves God since he is infinite, it doesn’t necessarily prove the “Christian”God, which seems obviously so due to his cultural assumptions. According toAquinas, however, God’s existence is not self-evident, and must be provedempirically. Hence Thomas believed that Anselm’s “ontological argument” simplyassumed the conclusion to be proved without showing external evidence.
In SummaTheologica, page 197, Aquinas states, “But because what it is to be God is notevident to us the proposition is not self-evident to us.” He later refutesAnselm’s ontological argument saying, “Someone hearing the word God may verywell not understand it to mean that than which nothing greater can be thought”. Rene Descartes is a scholar that revivesAnselm’s ontological argument to prove the existence of God using a priorireasoning. However, despite similarities, Descartes’ version of the argumentdiffers from Anselm’s in important ways. Unlike Anselm, which argues that Godis a being a greater than which cannot be thought, Descartes’ argument incontrast is grounded in two main beliefs: the theory of innate ideas and thedoctrine of clear and distinct perception. God’s existence is inferred directlyfrom the fact that necessary existence is contained in the clear and distinctidea of a supremely perfect being.
In Discourse on Method page 18, Descartesproves necessary existence by developing the first principle of philosophy ashe states, “I think, therefore I am”. Later, In Discourse on Method page 19, hemakes a clear distinction between the soul and body saying, “From this I knewthat I was a substance the whole essence or nature of which is simply to thinkand which, in order to exist, has no need of any place nor depends on anymaterial thing. Thus, this “I”, that is to say, the soul through which I amwhat I am, is entirely distinct from the body and is even easier to know thanthe body.
..”. Furthermore, Descartes describes the ontological argument as aproof for the “essence” of God, arguing that necessary existence cannot beseparated from the essence of a supremely perfect being without contradiction.He states, “reflecting upon the fact that I doubted and that, as a consequence,my being was not utterly perfect (for I saw clearly that it is a greaterperfection to know that to doubt), I decided to search for the source from whichI had learned to think of something more perfect than I was, and I plainly knewthat this had to be from some nature that was in fact more perfect.”