In conclusion to Descartes’s argument, if the most perfect thing has all predicates, then one of those properties must be existence. God is the most perfect and flawless being, hence, he must exist.
Similar to the ontological argument, the cosmological argument, also known as the first cause argument, is a classical argument for the existence of God. However, unlike the ontological argument, it derives the conclusion that God exists from a posterior premise (with evidence), as it is based on what can be seen in the world and the universe. It points the belief that there is a first cause behind the existence of the universe.
The cosmological argument is based on contingency (dependent on something else) and points out that things come into existence because something has caused them to happen, i.e. this essay would not exist without myself writing and producing it. The argument also states that things are caused to exist but they do not have to exist and that there is a chain of causes that goes back to the beginning of time, i.e. I would not be able to produce this essay without the movement of muscles in my fingers, moreover, the muscles would need impulses from the brain to tell the fingers what to do, hence there are a chain of causes before the actual essay is produced. Time began with the creation of the universe, which came into existence about 15 billion years ago. There must have been a first cause, which brought the universe into existence. This first cause must surely have necessary existence, which means nothing could have brought about this first cause or remove it. This necessary existence is the only one who could cause such a contingent universe. The Cosmological argument states that God has necessary existence, therefore God is the only one that is the first cause for the contingent universe.
St Thomas Aquinas developed the cosmological argument. He developed five ways to prove the existence of God. The first three ways forms the cosmological argument as a proof of the existence of God. These three ways are, motion or change, cause and contingency. The first way, motion, presents the point that in the world there are things that are in motion, and whatever is in motion must have been moved by something else. According to Aquinas, this chain of movement cannot go back to infinity. Therefore, there must have been a ‘prime mover’, which itself was unmoved, that initiated the movement. Aquinas clearly pointed that this ‘first mover’ is God.
“It is certain, that in the world some things are in motion. Now whatever is moved is moved by another” (Aquinas – Summer Theologica)
From this quote, Aquinas clearly points out that, an object only moved when an external force was applied to it. He continued that objects only changed because some external force had brought about the change. He spoke of things achieving their potential through an external influence. Aquinas used the example of fire making wood hot. When fire is applied to wood, it changes the wood to achieve its potential in becoming hot. Aquinas, in relation to the fire, stated that in order for a thing to change, actuality is required. If it did not, the thing would have to start the change itself, hence it would require both actuality and potential. However, Aquinas saw this as a contradiction, i.e. if wood could make itself hot then it would be hot already. Wood cannot be hot to begin with, otherwise it would not change and become hot. Therefore, Aquinas is emphasising the fact that wood is not hot already is its actuality.
Moreover, something must have made the fire change and come about, hence each change is the result of an earlier change. However, Aquinas reported that these early changes did not go on to infinity, so there must have been a prime mover He concluded this first mover to be no other but God.
“…it is necessary to arrive at a first mover, moved by no other; and this everyone understands to be God” (Aquinas)
Going on to Aquinas’s second way, which is very similar to the first way, however, here, he identified a number of causes and effects in the universe. Aquinas observed that something being the cause of itself is a logical impossibility, as this would mean that it would have has to exist before it existed. Aquinas, goes on to say that there have been first causer, and hence that primer cause is God.
“It is necessary to admit a first efficient cause, to which everyone gives the name of God” (Aquinas)
In the third way, Aquinas brings up the point of contingency of matter in the universe. He identifies that things come in to existence but then stop existing. He states that there must have surely been a time when nothing existed, however, for these to start existing, the universe must have always existed. Aquinas states:
“…if at one time nothing was in existence, it would have been impossible for anything to have begun to exist…therefore we cannot but admit the existence of some being having of itself its own necessity…”
Furthermore, there must have been a ‘necessary being’ to bring about this existence, this being God. He evaluated that if God did not exist, then nothing would exist.
In conclusion, Aquinas presents in his three ways of proving the existence of God that nothing could have existed without the existence of another. Moreover, something else must have caused the existence of this cause. Hence, a chain of causes is brought about. However, Aquinas emphasises that there must a beginning to the chain of causes. If the chain of causes is finite, then it means that this being does not have to rely on anything else to come into existence. There is only one such being…God.
