Comparing Aquinas And Descartes Arguments For The Existence Of God

Descartes argues that some ideas are more real than others. These ideas are those that represent substances and contain more objective reality. These ideas are first modes or accidents, finite substance, and infinite substance. Descartes

From the beginning of the third meditation, Descartes seeks to establish the existence of God

Aquinas argued the existence of God with five main points. Aquinas began by saying that nothing can be a cause of itself; rather every event was caused by some prior event. Therefore event A causes event B that leads to event C and so forth. He believed in this cause and effect relationship but believed that there must be a first cause as a starting point. When contemplating this starting point Aquinas rejected the possibility of an infinite series of events. This means that the universe has not existed forever and there must have been something from which every single event stems. There must be an uncaused first cause, which Aquinas concluded to be God. The first cause is called the unmoved mover. The unmoved mover is what set all other events and beings in motion.

     Aquinas’ third way argument states that there has to be something that must exist, which is most likely God. He starts his argument by saying not everything must exist, because things are born and die every single day. By stating this we can jump to the conclusion that if everything need not exist then there would have been a time where there was nothing. But, he goes on, if there was a time when there was nothing, then nothing would exist even today, because something cannot come from nothing. However, our observations tell us that something does exist, therefore there is something that must exist, and Aquinas says that something is God.

Therefore, it is more believable that the universe had a beginning and a personal creator. The third of Aquinas' ways is the argument of contingency. The world consists of contingent items- items that have a property are items referred to as 'being.' These items are generated and perish; they have a beginning and an end.

As with almost all of Descartes inquiries the roots of his second argument for the existence of God begin with his desire to build a foundation of knowledge that he can clearly and distinctly perceive. At the beginning of the third meditation Descartes once again recollects the things that he knows with certainty. The problem arises when he attempts to clearly and distinctly understand truths of arithmetic and geometry. Descartes has enough evidence to believe these things, but one major doubt is still present; the possibility of God being a deceiver. Descartes worry is that all the knowledge that he possesses through intuition could potentially be false if God merely chooses to deceive him. So in order to have a clear and distinct perception of arithmetic truths (and other such intuitive truths) Descartes delves into the question of God’s existence (and whether this God could be a deceiver or not).

Descartes’s attempt to prove the existence of God begins with the argument that he has the clear and distinct idea of God as the “most perfect being and that there must be at least as much reality in the efficient and total cause in the effect of that cause” (40). Therefore, this idea of God can’t be from himself, but its cause must be God. So God exists. In what follows I’ll explain these terms and why the premises seemed true to him.

The first part in which one can prove that there is a God is based on change. In the first part, Aquinas mentions that things change and that there has to be something which brings about that change, but at the same time is changeless. Aquinas states that “a thing in process of change cannot itself cause that same change; it cannot change itself” (Aquinas 45). For example, he gives an example about wood and fire. The wood is able to be hot but simply cannot make itself change without having an outside source that will cause it to become hot. The fire, that is naturally hot, will indeed make the wood hot and as a result, will change the wood.

To further validate his proof, he attempts to show God’s existence as an a posteriori claim. Descartes states that as humans we have the idea of God in our minds. We conceive God as a perfect being, that of perfect existence. As shown in the quote from page 37, this idea of God is beyond our reasoning to create, and must have come from God itself. Our idea of God certifies his existence. Descartes deviates from the method again, and his reasoning fails to provide an absolute proof.

     Anslem and Descartes’ theories both prove that there is a God and they both use some similar ideas in their premises’. For instance, they both rely on the faith that there is an idea of God; he is perfect and self evident. God could not have been conceived if there wasn’t a God. Though, Descartes says that the less perfect can not create something more perfect or better than itself, and that we are less perfect than God therefore we could not have created God. So, this proves the existence of God and an external world. On the other hand, Anslem says Existence is greater than conception and nothing greater can be conceived then God.

You can find Descartes’ proof of the existence of God in the Third Meditation. Although to understand this argument you have to look at his previous meditation where he begins to build his argument with the notion that in order for him to think, he must exist. From this observation, Descartes’ sees that the idea of his existence is very clear and distinct in his mind. Based upon this clarity and the fact that he has just determined his own

Aquinas first argument for God’s existence comes from the argument of change or motion. In this argument Aquinas observed that we live in a world in which things are always moving and movement is caused by movers. He states, “… therefore the thing which causes it to move be in motion, this too must be moved by something else, and so on. But we cannot proceed to infinity this way” (Aquinas 183). He makes this point that infinite regress is impossible because it implies that any series of events began with nothing at all.

Descartes makes an attempt to prove God’s existence throughout his third meditation. In his first premise he states that he has an idea of an infinitely perfect being. He uses the Principle of Sufficient reason to advance his argument; it states that everything must have a reason or cause. This put forth his second premise; that the idea of god must have a

This allows Descartes to begin to gain true knowledge, because his perfect being exists and would not allow him to be deceived all the time because perfection does not allow for that behavior.

Here Aquinas argues that everything that happens is the cause of something, but nothing can cause itself. If we trace back a cause all the way back to the beginning of the world, it could not have caused itself. Therefore, God must have been the first cause. Aquinas’ third proof is the Argument from Contingency. We see that everything here on earth is finite. People die, empires fall. All things must come to an end. That means things had to have a beginning where nothing was in existence yet. How did things come into existence? God. Aquinas’s 4th argument is the Argument of Degrees. Here we judge things to be a certain degree of good or bad. But what are we comparing that to? If they have a certain degree of good and bad, then what is the greatest degree of good? And that must be God. Aquinas’s final argument is his Argument from Design. Perhaps one of his strongest arguments Aquinas says that there must be an intelligent designer behind everything. Random objects don’t have any brains to act the way they do. But they are directed in the way they act by God.