While both St. Anselm and St. Thomas Aquinas believe they have found the methods which prove God’s existence, each of them come at the problem from unique starting points and apply different methodologies. In this paper I will compare and contrast both of the Saint’s methods and will conclude with how though St. Aquinas’ argument is more convincing than St. Anselm’s, neither are quite strong enough to stand up to close scrutiny.
St. Anselm’s approach to the existence of God can be defined simply with his self-evident ontological argument, God is “that, than which no greater can be conceived” (260). The Saint is making the case for God a priori in that is he deduces from the essence of God God’s actual existence. St. Anselm is arguing how it is possible to argue simply from a properly conceived definition alone. He does not need outside experience, unlike St. Aquinas who we will look at later, other than an ability to think properly: to not be a fool in the weak sense as of someone who cannot understand what words even mean.
As we deconstruct his argument we can assume many great things can be conceived, from fame to fabulous islands laden with treasure (as one of Anselm’s critics, Gaunilo will use as analogy). The question we then ask ourselves is what is greater than all? An island with treasure sounds great, but is there anything that could possibly be greater? For St. Anselm, determining how one thing might be greater than another can be attributed to St. Augustine’s Great Chain of Being. This helpful guide places a hierarchy on all things existing in the universe, from pebbles, to cats, to humans, and finally to God, and the higher up the chain they are the more good (greater) they are than the thing below them. With this hierarchy in mind, St. Anselm shows how it is better for things to exist in reality than just in the imagination, which also counters Gaunillo’s argument of a fantastic, and totally unreal island.
Notice also that St. Anselm is careful to not use the word “greatest” here, rather he just uses “greater”, and this avoids an arrogant assumption that we could possibly know what is greatest of all to be conceived. This then leads us into conception itself because if you think about ever increasing things in how they are greater, eventually you will arrive at the very thing which no greater can be conceived: God. And if you were able to conceive of something greater then that would actually be God. And so St. Anselm is saying that just by thinking about a carefully defined argument we can’t but help arrive at the conclusion that God exists.
St. Aquinas’ approach, on the other hand, can be defined as a posteriori, where he argues from the effects of God as we see them in our everyday world and from there builds his argument up towards God’s existence – a bottom up argument as opposed to St. Anselm’s top down approach. His is a cosmological argument that depends on experience and the senses, unlike St. Anselm’s argument which proves his point by definition alone, and while St. Aquinas offers five proofs in support of his argument, the Argument from Change is the one I will focus on here.
St. Aquinas is arguing that all change is caused by something else, be it a broken window or a barn fire, and some thing must have been the cause whose effects we can now see / sense. If we think logically about these actual experiences (unlike St Anselm who wants us to think carefully about an ontological argument) then we know someone must have thrown a rock or lit a match for either of these objects to have something happen to them, and so those things too have a cause (a vandal, or a pyromaniac for example). St. Aquinas extends this basic common sense thinking to argue that the universe itself, with all the things in it (including windows and barms, vandals and pyromaniacs) must also have a cause for them being in existence which he identifies as a “first mover”, and this “first mover” must therefore ultimately be God.
As we explored in St. Anselm, there is a point in which no greater can be conceived, meaning there is an ultimate point in which we can stop and say we’ve found God. St. Aquinas too is careful to not get stuck in an infinite regress of endless causes and says there must be a single, ultimate “first” (272) cause because we can sense the universe exists and therefore some thing must have been the cause that created it. Were there an infinite series of causes there would be no first cause meaning the universe wouldn’t even exist.
Of course how we get from the physical world of experience to the spiritual one involves a little help from God Himself. St. Aquinas writes, “The divine rights of grace do not abolish the human rights of natural reason,” (266), and from this we learn through the gifts of reason that God has given us that God’s existence can be revealed to us, even if exactly how God works or what He is made of would be beyond our reason alone to discover or comprehend.
St. Aquinas is also arguing against St. Anselm in that St. Anselm is assuming we can actually know God’s essence well enough for that to be self evident to us (as if it were, say a clear and distinct definition, as Descartes might put it), but St. Aquinas is saying we can’t possible have a self evident understanding of God’s essence to lead us to proving God exists. He is, in fact, calling the entire foundation of St. Anselm’s premise suspect and faulty. God can reveal Himself to us, but we can’t get their on our own.
Of the two arguments, I believe St. Aquinas is making a stronger case. St. Anselm is saying we have it within ourselves to (innately) know God, that we do not need anything other than the gifts of reason God has given us to know him, however this is all predicated on the notion that words themselves actually mean exactly what we believe them to, that language has the ability to stand in representation perfectly of that which is being described, and also that we are even capable of actually understanding God’s essence. St. Aquinas is, I believe, far more practical and scientific because we can rely on our senses which seem to serve us quite well enough in the everyday world. The main weakness in St. Aquinas’ argument however is with the senses themselves. How can we be sure we are actually sensing the world well enough to draw definite conclusions about what is causing what and how? Are our senses deceiving actually us? This is an aspect he never addresses.
And so I conclude that neither Saint has a bulletproof argument making the case for the existence of God. The main cause for hope, however is that both Saint’s believe we do have the ability within us, either through an ontological thought experiment or through practical experience, to use our gifts to know God. We will have to wait nearly 400 years for Descartes to thoroughly examine the flaws in both Saint’s premises to arrive at a more concrete argument for the existence of God, but he too will carry on the tradition of showing how we have it in ourselves to discover the greater truths of being and the existence of God.