The Cosmological Argument

Aquinas' Summa Theologica

Thomas Aquinas, in his book Summa Theologica, makes arguments for the existence of God in the third article. Aquinas is trying to prove that God exists without anything being required of him to exist. He is also trying to prove that God is the starting point of all things that exist in reality. He therefore asserts that without God there would be nothing.

Aquinas begins by saying he has five reasons why God must exist automatically without any denial. The first reason Aquinas gives has to do with the idea of “motion.” We know from observing our world that things move because something has moved them. When a little boy kicks a small rock, the rock will move, but if no one kicks or moves the rock it will not move. Everything in our world is moved from something else. These occurrences are based on the cause and effect relationship of the world. The natural world reacts every time to this process. If one thing is moved then it definitely had a mover. If that mover itself had a mover, and the process continued, no matter how long it went it would end with a starting point and a first mover. Just like dominoes. The last domino can attribute its falling to the domino before it and that one to the domino before it and all the way back until it reaches the very first domino. The regression of movers is not infinite; it is finite and always has a starting point. So Aquinas asserts that since our natural world has been given this characteristic of cause and effect, we must conclude that our world came to be from a first mover: an ultimate starting point. This idea also ties in with his second reason for the existence of God, which is about the order of efficient causes. The first efficient cause could not have been caused itself, or it would not be the first starter. God is therefore the first mover, and the first efficient cause that started everything that is in existence. Since it is not logically consistent to believe in an infinite regression of causes, there must have been a first efficient cause, and that cause is the only necessary entity, which is God.

The third point that Aquinas makes is that “the effect is taken away if the cause is taken away.” (Aquinas, pg. 42) According to Aquinas, if you take away God then nothing would exist. We know that this is not the case and things do in fact exist. Since we are dealing with finite things Aquinas says that they have the possibility of not existing, and whatever could not exist anymore at one point must not have existed. Therefore, if something finite does exist, then there must have been something existing out of necessity before it that doesn’t owe it’s existence to anyone, but exists alone. This being would have to be intrinsically necessary because just like the efficient causes, there cannot be an infinite regression of necessary beings.

The fourth point that Aquinas makes has to do with the gradation of things. When we refer to something being more beautiful or more perfect, we are comparing it to some idea that must be the most beautiful or perfect. The same as when we say there is more of something here and less of something there. For his argument, Aquinas uses the example of fire to show that it is the greatest source of heat. He says that the fire is what causes other things to be hot, and to get hotter. Therefore, according to this line of reasoning, there must be someone who has the attributes of what is most good and most excellent in which we are able to compare ourselves to. This idea of the “ultimate” has been an argument for the existence of the supernatural all the way back to the time of Socrates. He says in Phaedo, “If we had this knowledge, we knew before birth and immediately after not only the Equal, but rather the Greater and the Smaller and all such things… So we must have acquired knowledge of them before we are born.” (Phaedo, pg. 66) Socrates was arguing that when we call one stick unequal to another stick in size we are comparing an understanding of something that is equal. We cannot refer to something being equal, however, unless we have some idea of what true equality is. Because of the gradation of things in our world it follows that there must be an ultimate.

The fifth and last argument Aquinas makes for the existence of God has to do with the governance of things. We know from observing nature that inanimate objects do not work towards anything. Their purpose does not come from goals that they have placed. Their use is based off something that has knowledge taking that object and using it for their purpose. Aquinas used the example of an archer who takes his bow and arrow and makes it shoot at something. The arrow cannot shoot on its own because it lacks the intelligence. Someone who has knowledge must come along and use the arrow. Therefore, Aquinas argues that an entity with intelligence must be in control of all the laws of nature, and of all the order of nature.

Final Thoughts

The five evidences that Aquinas gives makes the claim for an uncaused, first moving, efficient, necessary, ultimate, and governing God. His argument is a strong non-deductive argument that although does not prove outright that God exists, it makes incredibly brilliant observations that point to a greater-than-can-be-thought God. His arguments consist very well with logic because without God there would be no rational explanation for the existence of the world. To assume that there must have been an infinite number of causes is illogical because we live in a finite universe. Also, to assume that this universe did come into existence at one point and before that point nothing existed is absurd. Just as Aquinas argued, from nothing, nothing comes. The arguments of Aquinas show the existence of God in a very effective and logical manner. However, since Aquinas is merely dealing with general revelation and issues of creation, it does not lead anyone to the knowledge or specifics of God. This argument is strictly arguing for Natural Theology. Socrates, who understood the idea of a gradation of perfections, did not come to the same conclusion as Aquinas. He argued for the existence of the soul and therefore the rest of the supernatural realm, but that’s as close as he got to the truth. I believe that this argument is a good stepping-stone that can lead atheists and agnostics to a true knowledge of Christ, but there is an element of danger there. Not only does the door open to the possibility of God, but also it opens the possibility of any God. In my opinion, that is a major weakness in the argument. This is considered a false alternative. Aquinas is only arguing for God’s existence, and neglecting other possibilities. For example, instead of God creating everything, there could be a “cosmic scientist” that is conducting experiments on us, or a group of aliens from deep in outer space who created us. Basically, he left out other possibilities that weren’t mentioned, but made the argument to be either God exists, or he does not. Nevertheless, I still appreciate the points Aquinas makes. His argument shows that God really has given us an understanding of who he is through the creation like Romans 1:20 says, ““For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse.” I believe that Aquinas’ argument goes extremely well with this verse because it shows us that God has made the evidence of himself clearly seen to all of us in his creation.