Aristotle took this further in his book Metaphysics, believing that the prime mover could not be part of the ordinary chain of physical and material causes, and so must lie outside the universe. He believed the prime mover must be non- spatial and eternal, its presence must activate the world and it must be good and perfect. He also believed all things are encouraged towards a good and ultimate goal.
Aquinas extended this view in his first way from motion. He believed that motion was the reduction of something from having the potential to move or change to actually moving or changing. For this to happen, it has to be put into motion by another, and the same for the one before. However, this series cannot be infinite, for then there would be no first mover and thus no motion. We can see motion in the universe, and thus there must be a first mover, which has been moved by no other, that explains the bringing about of motion and change, and this “everyone understands to be God.”
Aquinas’ second way, From Cause, concerns causes and effects. The world is a series of events, and every event has a cause. Nothing can be its own cause, as then it would have to be prior to itself. Infinite regression is impossible as then there would be no first cause and thus no series of events; no universe. This leads to the conclusion that there must be a first cause which itself is uncaused, which all subsequent causes and effects are dependent on, and this Christians imagine to be God.
The Kalam argument is an argument put forward by al- Kindi and al- Ghazali in which it is believed that for anything to come into existence, it must have a cause. The universe came into existence, and so must be argued to have a cause. The Kalam argument proposes that if the universe has a cause, it must be God, and therefore God must exist.
This argument was reworked by William Lane Craig. He put forward that the same principles, but additionally, rejects infinite regression as this means no cause, which would not then cause the existence of the universe, and so the universe must be finite and have first cause. Space and time originate from within the universe and so the cause must be beyond space and time, and thus scientific explanation. Therefore the cause is personal, not physical.
Aquinas’ third way, from necessity and contingency states that everything is dependent upon factors outside of itself, thus they are contingent and have the possibility to not-be rather than be. In theory, given infinite time, the possibility for all things to not exist would have been realised. This would mean there would be nothing. ‘Nothing can come from nothing’ (Parmenides) and so if that had happened there would be nothing now. This shows the need for there to be a necessary being, described by F.C. Copleston as a being that must, and “cannot not exist” which itself depends on no other, and continues the existence of the universe. This people believe to be God.
Leibniz argument avoids the problem of infinite regression by interpreting the endless series as a series of explanations rather than causes: the principle of sufficient reason states that there must be a sufficient reason for why things are. Infinite regression means that by going back in time forever we never reach a complete explanation that explains the whole. Even if the universe is eternal and has always been in existence, we would still need to establish a sufficient reason for its existence. Since the universe does not contain within itself a reason for existing, the reason must lie outside the entire sequence, this must be an eternal and necessary being- God. This makes the system coherent as we know the ultimate explanation for things; God requires no further explanation.
F.C. Copleston agrees with the rejection of infinite regression, for an infinite number of contingent beings can only continue their, it doesn’t explain what started the sequence, as contingent beings cannot bring themselves into existence. An infinite chain of train carriages can move nowhere without and engine, likewise a series of events couldn’t have begun without a necessary being to support the contingent beings. Copleston concludes that as the universe doesn’t contain within itself its own reason for existing, it must lie outside the universe in a self- explanatory being.
Richard Swinburne more recently argued that the chance of there being nothing is much greater than there being something. Yet there is something, suggesting a creator. The existence of the Universe can be explained by God. “If we can explain the many bits of the universe by one simple being we should do.” (Is There a God Oxford Press 1996).
To conclude, the cosmological argument requires that God be a complete explanation for the existence of the universe, containing within himself all the characteristics that are necessary for him to be so. The argument is essentially attempting to prove that God is a necessary being, and the simplest explanation for the existence of the universe.
