Thomas Aquinas’ Theories on The Existence of God

What do we know about God? Who is he? Or is it she? Why have millions revered and worshipped him for centuries? Does he exist? These are questions that some of people have asked themselves at one time or another as they try to understand his presence, his existence in the world. One of the people who asked this question and came up with possible answers is Thomas Aquinas. Thomas Aquinas was an Italian, Dominican priest and Spiritual theologian who was also a very well respected and highly influential philosopher from the medieval period. Aquinas tried to confirm the answer to God’s existence by coming up with a five proofs; proof from motion, proof from efficient causes, proof from possibility and necessity, proof from gradations of perfection and proof from the governance of things. I will show that Thomas Aquinas was right in his assumptions on the existence of God. I will do this by first explaining his theories on the existence of God and then supporting his claims through other philosophers who, through their own assertions, also strove to show the existence of God.

In proof from motion, Aquinas argues that we can tell that some things are in motion through our senses. This motion is caused by another motion; potential motion becomes actual motion. Therefore, something can not be at potential and actual motion at the same time hence something can’t move itself. “For example, something actually hot cannot at the same time be potentially hot, although it is at the same time potentially cold.” (Abel 43) What is in motion has been put in motion by something else and so on and so forth. “A stick, for example, only causes motion because a hand moves it.” This can’t go on to infinity; there has to be an initial mover put in motion by no one else; “a first cause of motion, one that is moved by nothing else” (Abel 43). This is understood to be God. In proof from efficient causes, Aquinas purports that nothing exists before itself. Nothing is the efficient cause of itself. It is impossible to go to infinity in efficient causes. “If a previous efficient cause does not exist, neither does the thing that results (the effect). Therefore, if the first thing in a series does not exist, nothing in the series exists. If the series of efficient causes extends ad infinitum into the past, for then there would be no things existing now.” (Gracyk) This is evidently false. It is now prudent to agree to the existence of an initial efficient cause; God. In proof from possibility and necessity, Thomas Aquinas states that there are things that are possible to be and not possible to be; decomposable things. “Therefor, if nothing existed, nothing could begin to exist, and so nothing would now exist, and this conclusion is obviously false.” Therefore there is a thing that exists on its own. This thing/being is God. Aquinas says that proof from gradations of perfection is as a result of graduation in things; some things are better than others. This implies that there is a reference of measurement against which a thing is evaluated. Therefore the 'maximum in any genus is the cause of all in that genus.” Therefore there is a thing that is the cause of all other being; this being is God. Proof from the governance of things says that we see things in the world working or moving in a particular way and most of these things lack intelligence but are still designed to function in a set way; they reach their goals not by chance, but by striving. “But things that luck knowledge, do not strive for goals unless a being with knowledge and intelligence directs them, as, for example, an archer aims an arrow.” (Abel 44) Therefore, if there is a design, there is a designer; the designer is God.

David Hume, a Scottish philosopher, supported Aquinas’s theories on the existence of God. He did this through three fictional characters; “Demea, the orthodox believer; Cleanthes, the theologian; and Philo, the skeptic.” (Vaughn 70) Hume begins his argument with Cleanthes saying that he world is one complex machine that consists of immeasurable other lesser machines. Just like man made or artificial machines are made by intelligent agents (humans), the natural world must follow the same pattern and also be the work of an intelligent being (God). Demea refutes this claim because it is a posteriori argument and states that only an a priori argument can unquestionably determine God’s existence. Philo picks up from here and adds that it is dubious to argue that because we see a house and can infer with absolute certainty that it has a designer or builder, we cannot apply the same logic to the universe since the “dissimilarities between the two phenomena are enormous.” This is because “the intelligence that we observe in mankind is just one of the many forces that produce changes in the world” and thus it would be erroneous to assume “that intelligence is the one thing that is responsible for the universe as a whole.” Demea then says that if something exists then it must have a cause or justification for existing. This is because it is inconceivable for anything to be its own cause of existence. Going back in infinite succession will end at an infinite number of causes or end at an existent being. “But since no series of events can extend back infinitely, there must be a being that has its reason for existence in itself.” (Abel 55) This assertion by Demea is almost similar to Thomas Aquinas’s proof from efficient causes. They both agree on an initial cause; what you see or know was preceded by something else and that was also preceded by something else and so on and so forth. Through Demea, Hume argues that God is the first cause. This means that the world works in a series of cause and effect. Therefore, an original or first cause exists that would have started the world’s motion. That first cause is God. This is similar to Aquinas whose argument from efficient cause states that nothing exists before itself.

Immanuel Kant argued for the existence of God through his morality argument based on practical reason. Through his definition of the categorical imperative, Kant asserts that our actions should be “universalizable”. This means that the maxim on which our action is based must be one that we could consistently will that all persons follow. You can not do anything that you wouldn’t be willing to let everyone else do as well. For example: If you expect others to always tell the truth then you are also to always tell the truth as well. Kant argues that we are compelled to seek the highest good (summum bonum) which constitutes happiness and moral virtue; happiness is as a result of virtue. He also states that if one is morally inclined to complete an action then you are able, within reason, to carry it out. “He accepted that it is not within the power of humans to bring the summum bonum about, because we cannot ensure that virtue always leads to happiness, so there must be a higher power who has the power to create an afterlife where virtue can be rewarded by happiness.” 

Rene Descartes, a French philosopher, proved the existence of God by using his method of doubt. This is where he is skeptic of everything he is not absolutely certain about. He can not discard everything because it will be endless to do so. The senses deceive therefor he will not completely trust those that have deceived even once. He will look deep within and try to analyze himself so as to get a more definite insight of himself. He is certain he is a thinking being and “that his mind contains an idea of an infinite being and reasons that he himself-who is merely a finite being-could not have invented such an idea.” Descartes concludes that this “idea of the infinite being must have been placed in his mind by the infinite being itself”. He questions himself on how he could know what he knows or understand that he doubts or desires or “wholly perfect, unless there were in” him “some idea of a more perfect being which enabled” him to identify his own faults in contrast. Thus, this leads him to conclude that God exists; God being the infinite being.

Another philosopher who showed that God exists is William Paley. He did this by expounding on his watch maker analogy of finding a stone and a watch on his path and asking himself where they both came from. He answers himself by saying that he stone has most probably lain there forever. For the watch on the other hand he has a different answer. Its “several parts are framed and put together for a purpose, e.g., that they are so formed and adjusted as to produce motion, and that motion so regulated as to point out the hour of the day; that, if the different parts had been differently shaped from what they are, if a different size from what they are, or placed after any other manner, or in any other order than that in which they are placed, either no motion at all would have been carried on in the machine, or none which would have answered the use that is now served by it.” After observing and examining the mechanization of the watch and getting some insight on its capacity, it is possible to infer that it most definitely had a maker who designed it to serve a specific function. All the small intricate parts coming together to serve a purpose, tell time. To him this is a clear indication that the universe too, with all its different cogs that come together in a large scale to sustain life, has a grand intelligent designer, God.

What are the chances that the world just came together and got everything right, from how nature works to how physical matter interacts; gravity, energy, force? The chances are very small. The earth works mostly in systems that we can see. Water gets heated, evaporates, cools and becomes rain. A guava tree grows; animals eat the fruit and defecate the seeds across the forest floor thus sprouting new trees. An apple falls down and not up, gravity. There are several animals that use camouflage as a defense mechanism and others as a way to hunt. I can also state that the earth is just the right distance from the sun to sustain life. All these micro mechanisms come together to form one big system. This is evidence of a complicated system that rules out chance as its precursor. An intelligent being had a hand in this; there is purpose in every little detail. Another example is the earth spinning on its axis so that we may have day and night. All this consequently shows that the intelligent being behind all this is no doubt God.