Jennifer Wilber works as an ESL instructor, substitute teacher, and freelance writer. She holds a B.A. in Creative Writing and English.
Thomas Aquinas and the Proof for God’s Existence
According to the 13th-century Catholic philosopher and theologian St. Thomas Aquinas, the existence of the natural world requires the existence of God. He uses his own five proofs for the existence of God, or “the five ways” to prove his theory that God exists, and that the natural world can only exist if God exists. But is there any proof that his proofs for the existence of God are true? Believing his claim that God exists based on the "proofs" that he made up himself makes no more sense than believing that what the Bible says is true simply because the Bible says that itself is true.
What are the Five Ways?
St. Thomas Aquinas outlined five ways to prove the existence of God. He claims that these “ways” prove that a God must exist for the universe and nature to have come into being.
Prima Via: The Argument of the Unmoved Mover
According to the first way, we can see that at least some things in the world are constantly changing. Whatever is changing must be changed, or moved, by something else. Whatever is changing it is itself changed, so it too is being changed by something else. This chain of changers or movers cannot be infinitely long, so there must be primary changer that causes change without itself changing. This, according to Aquinas, must be what we understand to be God. Since a potential doesn’t exist yet, it can’t cause itself to exist and so can only be brought into existence by an outside mover, whom already exists. According to Aquinas, "[t]he mover and the thing moved must exist simultaneously".
Secunda Via: The Argument of the First Cause
The second way states that, though we can see that things are caused, it is not possible for something to be the cause of itself because this would mean that it existed prior to its own existence, which is a contradiction. If something is caused, then the cause must also have a cause. This cannot be an infinitely long chain, so there must be a cause which is not itself caused by anything further; a first cause. This is what we understand to be God, according to Aquinas’s theory. The causes need not be sequential events. Aquinas argues that the first cause is first in a hierarchy, rather than sequentially. The first cause, or God, is a principal cause, rather than a derivative cause
Tertia Via: The Argument from Contingency
The third way says that we see things that are possible to be and possible not to be, or perishable things. However, it everything were contingent and, and so, capable of going out of existence, then, given infinite time, this possibility would be realized, and everything would cease to exist by now. But since things clearly do exist right now, there must be something that is imperishable. According to Aquinas, this necessary being is what we understand to be God.
Quarta Via: The Argument from Degree
According to the fourth way, things in our world vary in degrees of goodness, truth, nobility, etc. There are sick animals and healthy animals. There are well-drawn triangles and poorly drawn ones. Judging something as being "more" or "less" implies some standard against which it is being judged, so there must be something which is goodness itself, and this is what we understand to be God, according to Aquinas.
Quinta Via: Argument from Final Cause or Ends
Aqunias’s fifth way states that there are various non-intelligent objects in the world which behave in regular ways. This can’t be due to chance since, if it were due to chance they would not behave so predictable. Their behavior must be set, but it can’t be set by themselves since they are non-intelligent and do not know how to set their own behavior. This behavior must be set by something else, and that thing must be intelligent. Aquinas believes that this is what we understand to be God.
Do Aquinas’s Five Ways Really Prove the Existence of God?
Aquinas claims that God is an unchanging source of change, and that for change to exist, there must be an unchanging source of change. There is no real reason that change must come from something that remains unchanged itself. It is possible to change something, and then be changed yourself.
Aquinas also claims that God must have always existed and will always exist. If God has always existed, where did he come from and how did he get there? Why is it necessary for the original creator to have always existed? Is it not possible that something could have existed, created something, and then stopped existing? For example, you were created by your parents, but they will stop existing eventually, just as you will stop existing eventually.
Perhaps the original ultimate force in the universe, AKA God can grow and change over time, just as the universe itself grows and changes over time. And perhaps the Universe will end one day only to give rise to the next universe and start the cycle over. If God never changes, neither will the universe, as the universe and God are one in the same. If nothing ever changes, then there is no purpose for the universe to exist. Aquinas was wrong in assuming that God must necessarily be some external force outside of the universe. Perhaps what we understand to be “God” is instead the universe itself, in all it’s ever changing, ever evolving glory.
Even if Aquinas was correct and there is some outside creator, there is no proof that this God is ultimately intelligent or perfect. If he were, everything he created should then be perfect. And since nothing in existence is perfect, then God cannot be perfect either. Assuming that God must be perfect and supremely intelligent is no different than a small child looking up to his parents and thinking that they are perfect and essentially God-like.
No External Creator Needed
Of course, it isn't necessary for there to be an intelligent creator for the universe and the natural world to exist. It could have happened by chance. The argument that everything in nature is too complex to be chance doesn't hold up. For example, when life first appeared on Earth, there could have been any number of types of creatures that started to evolve, but only the ones that were viable lived on to continue to evolve. Perhaps there are lifeforms that can't survive in oxygen. Only life that can survive in oxygen would have continued to survive and evolve in the Earth’s present environment. Lifeforms simply adapt to their surroundings and only the ones that can survive do.
Life started out as single-celled organisms, but eventually grew to be more complex. The complexity of life arose very slowly as life adapted to become better suited to environmental conditions. Therefore, there doesn't necessarily have to be an intelligent mind creating everything in existence. The natural world does just fine without supernatural intervention.
Aquinas's five proofs don't hold up. There doesn't necessarily have to be an unchanging source of change, and unoriginated source of originated beings, a necessary source of unnecessary beings, an absolutely perfect source of all degrees of perfection, or an intelligent creator. The existence natural world does not require the existence of God, nor does it make the existence of God more probable. The universe and the natural world just are as they are, no outside help required.
© 2018 Jennifer Wilber
Ellabulldog on December 29, 2019:
Ihova Deus said you are not a philosopher so can't comment on Aquinas. Well Aquinas had no degree either.
Thomas Aquinas on here confuses our universe with Existence. Existence entails this universe, any other universes concurrent with ours, any universes prior to ours and any future universes.
We are limited in our knowledge and constrained by our space time. It likely is something we can never know.
Wishful thinking is not philosophy. Propaganda for the Church isn't philosophy.
Aquinas and his 5 ways is a big waste of time. 700 years ago some may thought it worthy of consideration.
Today people spend a lot of time trying to defend and explain what he meant but nobody can show that any of the 5 ways adds anything to human knowledge.
Thomas Aquinas on September 17, 2019:
@Roq Steady re: “The necessary component of reality (the fundamental basis of reality) can not be a ‘being’ that is separate from everything else, because there would be nothing outside of it to construct anything else from, and so you run into the incoherent notion of creation from nothing.”
God is not some separate being, He is total act, where all potentials come from Him.
For Aquinas, God cannot be self-sufficient if He is a material being because material beings are composed of matter. To be composed of matter is to be in potency (change) since whatever is in matter is in potency. Since to be material is to be in potency, and since there is no potency in God, it follows that there is no matter in God.
Aquinas distinguished between finite substances and the infinite substance. For Aquinas, man is not a mode or even an accident of a single Substance. On the contrary, a man is an individual finite substance. Moreover, in contrast with the rationalist notions of substance, Aquinas denied that a substance was something which was necessarily self-sufficient.
Instead, substance was understood to refer to a subject that maintains its identity throughout a change. Thus even finite beings could be substances because they changed while retaining an identity.
Roq Steady on August 18, 2019:
@Thomas Aquinas re: "the existence of only one contingent being necessarily arrives at a non-contingent being".
This is just wrong. The necessary component of reality (the fundamental basis of reality) can not be a "being" that is separate from everything else, because there would be nothing outside of it to construct anything else from, and so you run into the incoherent notion of creation from nothing, which Thomists just seem to gloss over with little thought, whilst accusing atheists of claiming such.
In fact, although it is little noticed outside philosophy, Spinoza destroys Aquinas's argument (In the first part of Ethics "On God") and proposes a much more sensible idea: He still uses the word "god", because that is where he started, but he strips off all the unnecessary bits that have nothing to do with... anything really (ie mind omnipowers etc. etc.) and proposes a fundamental necessary, sufficient substance that has two parts, the substance itself (natura naturata) and process (natura naturans). Hence his famous phrase "Deus sive natura", which means god or nature. That basic substance is then the basis for the construction of everything else, including us. It is a simple and elegant idea that is pretty much how modern science views things - i.e. there is probably some fundamental material such as say strings (trendy right now), along with some fundamental laws of physics that dictate their behaviour and build up into the laws of physics we see in our universe. So no necessity for theistic gods of the gaps after all.
As to first cause arguments, the quantum mechanical nature of space/time puts a bit of a kybosh on these - maybe the cosmos is an infinite expanse of empty space punctuated by quantum level events (physics now knows empty space isn't really empty) that can sometimes lead to universes - really noone knows yet (we don't have a good model of quantum gravity), but disembodied minds beyond space and time make little sense, why would such a complex thing exist at all? The only minds we have ever seen, require physical brains to run on.
Thomas Aquinas on June 21, 2019:
“And perhaps the Universe will end one day only to give rise to the next universe and start the cycle over.”
Again pushing the question back, but not solving it. If the universe came into existence (as most of science agree, space time had a beginning), it needed a cause. If a contingent thing (universe) is the cause of another contingent thing (next universe), this cannot go on forever. In the multiverse theory, there are any number of universes that regress back. This argument is similar to a chandelier with lots of links in it’s chain. The chain can be infinitely long, but if it doesn’t have a hook to attach it to the ceiling, the chandelier cannot hang.
So too with contingent beings (not just the universe). In Aquinas’ proofs, there is not a premise saying the universe is contingent. Aquinas thought the universe could be eternal, but the existence of only one contingent being necessarily arrives at a non-contingent being. For example, you could say a cup of coffee “came into existence” by water being poured through coffee beans, pressurized through heat, so on. But let’s go further, how does the water that made the coffee come into existence at any moment? How does the hydrogen and oxygen making up the water hold itself into existence? How do the sub-atomic particles that hold hydrogen and oxygen together hold itself into existence? What is keeping all the changes in existence?
The potential for coffee to exist at any moment is being actualized by the existence of water, which follows its existence from the potential of the atoms actualizing, where these atoms are in existence because of the potential of the sub-atomic particles being actualized. These are essentially ordered series of causes that must receive there existence from something with inherent cause, pure act, no potentials. This is God.
Thomas Aquinas on June 19, 2019:
“It is possible to change something, and then be changed yourself.“
That pushes the question back, it doesn’t solve it. What is changing you when you change something? Well something else. What’s changing that? Something else! If something goes from potential to actual (log potentially hot to actually hot = fire) it requires something else to change it (match, friction, and oxygen). We define God as the ultimate cause, total act, unchanging without any potentiality. He is the end of the regress of efficient causes. To ask who caused God is nonsense because who created the Being that was never created?
“Is it not possible that something could have existed, created something, and then stopped existing?”
An interesting question, but Aquinas’ proof for God shows how He interacts with the world in real time. It is He who sets the electrons in motion at their precise configurations and holds everything in existence. If He were to stop thinking of you, you would cease to exist.
“The universe and the natural world just are as they are, no outside help required.”
It is for you to prove this statement. Given that science is not the only source of knowledge and that it cannot prove God’s existence, demonstrate how God is not necessary. Where did evolution and adaptation come from?
Miebakagh Fiberesima from Port Harcourt, Rivers State, NIGERIA. on June 19, 2019:
This contribution is well noted.
Miebakagh Fiberesima from Port Harcourt, Rivers State, NIGERIA. on September 02, 2018:
Hi Jennifer,good to know that, and congratulations! But Aquinnas in all his learning, thinking, theory, teaching, and preaching was considered a doctoral. What do you say?
Jennifer Wilber (author) from Cleveland, Ohio on September 02, 2018:
I originally wrote this paper for an assignment for a philosophy class. This is a conclusion that any undergrad could come to. It doesn’t take a Ph.D. in philosophy or theology to realize that God doesn’t necessarily exist just because a Catholic priest came up with a theory to “prove” his own pre-existing belief system.
Miebakagh Fiberesima from Port Harcourt, Rivers State, NIGERIA. on September 01, 2018:
@jehova: even a doctoral would make the same philosophical mistakes worst than Jennifer. It is argumentum ad vulgar. The only reasoning that should hold water is argumentum ad volerum. Thank you.
Iehova Deus on September 01, 2018:
So a freelance writer with a B.A. in Creative Writing pretends to have disproved Thomas Aquinas's "Five Proofs for the Existence of God"? And without citing a single philosopher or other source? The reader should seek out a work on the subject by an author with a Ph.D. in Philosophy or Theology.
Miebakagh Fiberesima from Port Harcourt, Rivers State, NIGERIA. on August 09, 2018:
Hello Jennifer, thank you for philosophical. You are in the same class with Aquinas. In reality, God does exists. If the creative materials of the world does not tell one that there is God (not there is a God), nothing can do. The fact that God did not change, will not mean that the creative universe will not change.
My parents did not create me. They begot me. And, this applies to every person,includingyour goodself, right? If my parents change, and I see they change in some ways (that's to they likeing), and it means nothing to me. God is not a human being or like the material cosmos that he should change. He is creator.
Let's take the potter as an example. The fact that he can break a mould pot and used the same materials to make another pot does not and will not prove that the Potter has change. He may only change his mind and direct it to do something else other then another. But he remained the same Potter, right?
Thank you, and have a nice time.