The Cosmological Argument is a posteriori argument (knowledge gained after experience) which attempts to prove that there is a rational basis for the belief in God. This argument is synthetic as it uses senses and is distinctive as it uses evidence of the universe to prove that God exists. The argument attempts to prove that God exists by evaluating the scale and nature of the cosmos. In order for this argument to succeed it has to be inductive and produce overwhelming evidence to show Gods existence. Arguments, like this one, can be interpreted in various ways so there will be different conclusions about God, in other words religious ambiguity. Furthermore most supporters of the Cosmological Argument argue that the universe could only have come into existence if it were caused by an uncaused cause. Thomas Aquinas, a Dominican friar, adapted the argument. He stated that everything must have a cause, nothing is its own cause, and a chain of causes cannot be infinite and that there must be a first cause. This first cause must be an infinite, necessary being.
Aquinas’ first way is the way of motion. Aquinas uses the existence of motion of demonstrate the existence of God. He said that “Nothing can be moved from a state of potentiality to actuality, except by something in a state of actuality”. Here Aquinas uses Aristotle’s argument of the Prime Mover. The Prime Mover causes the movement of other things, in other words, it does not start off the movement by giving it some kind of push, but it is the purpose, or end, or the teleology, of the movement. Change in an object is always caused by an external movement – nothing can change itself. These movements go back in a causal chain, but Aquinas said this chain cannot be infinite so there must be something which set off this chain of movements, an unmoved mover, Prime Mover (God). Things change to fulfil their potential. If things could change themselves they would be both