Thomas Aquinas famously formulated his version of the cosmological or “first cause” argument. According to this argument, the things which we see around us now are the products of a series of previous causes. But that series cannot go back in time forever. Thus there must be some first cause which was not itself caused by anything else. And that first uncaused cause is God. A lot of the argument is based on Aristotelian views, of that there is a greater being that started the infinite regression of the earth, an ‘unmoved mover’.
Aquinas wrote about the ‘5 ways’ or Quinque Viae to help establish his argument based on observation and evidence that there is proof of a ‘summum bonum’. The first three ways are concerning the cosmological argument. The first way concludes that there must be an unmoved mover, infinite regression of the universe must been started by something and Aquinas believes that this unchanged changer is God. There must be a prime mover to change things between potentiality to actuality.
Aquinas himself quotes that “The chain of movers cannot go on to infinity because then there would be no first mover and consequently no other mover”. The second way explains that there must be an uncaused causer as nothing can cause itself to exist if it does not already, something must have caused the chain of infinite regression. The third way concludes that everything in the universe is contingent on something for existence, for example, babies are contingent on their parents, and without them they would die.
If everything is contingent, there must be a necessary being that created the universe into existence. The prime mover, God, is an exception as he is not contingent on anything; God exists outside time and space. However, although Thomas Aquinas felt that he had good evidence to prove his theory about God existing, many people critisised the Quinque Viae. David Hume, a famous empiricist philosopher criticised the argument multiple times.
He thought that as there is no empirical evidence we cannot tell what the cause of the universe is, we cannot know that God is a necessary being as we would have to see the cause and effect to agree. Due to the lack of knowledge we do not know that the universe did not always exist, or like Einstein suggested that it is the nth universe in a series – the Oscillating Universe Theory. We also do not know that if the universe does have an uncaused causer, why is it necessarily the Christian God? It may be a group of Gods or another religions God, for example, Buddha.
In 1948, Fredrick Copleston a Jesuit priest (in support of the cosmological argument) and Bertrand Russell a Philosopher and logician (against the cosmological argument) went head to head in a radio show cosmological debate. Copleston believed in the contingency of everything in the universe and that it requires a necessary being (God), but Russell argued that the universe simply exists, there needs to be no reason for it and it is illogical that Christians should demand explanations for everything.
William Lane Craig, an American analytic philosopher also formulated another cosmological argument, Islamic in origin, dating back to 850 BCE. His premises were that everything that begins to exist has a cause for its existence, this cause is God. Although Thomas Aquinas provides good theories behind his argument, the counter arguments from Hume and Russell are also logical. This makes it hard to use the cosmological argument to prove the existence of God as the criticisms also make sense.