Aquinas’ cosmological argument is an Aposteriori argument composed of three strands, motion and change, cause and effect and contingency.
The first of these ideas, motion and change, intends to prove the existence of a God by arguing that everything we experience within the cosmos to be in motion has evidently been set in motion by another thing. This is simply the explanation of something achieving its potentiality with the assistance of an actuality prior to it; for example, if you are to look at fire and the potentiality for wood to become hot, you will see that the actuality (fire) is necessary to fulfil the potentiality for the wood to become hot. Aquinas then relates this theory to the cosmos and explains that we cannot just assume that the cosmos just is, and that is all, because if a potentiality, for example wood becoming hot, could occur without an actuality (fire) then it would be achieved by itself and therefore the wood would be consistently in this state and as we know that wood is not constantly hot we can see that when applied to the cosmos there must exist an actuality external to it that fulfils and maintains the potentiality of the cosmos to exist.
Aquinas’ second theory is based on cause and effect. This builds on that of motion and change and proceeds that every effect we experience within the cosmos has an obvious cause prior to it. Aquinas used this undisputed fact to suggest that therefore if the effect is the existence of the cosmos, the only plausible cause would be God.
Aquinas argued that a series of infinite regress is impossible and cannot be assumed as a valid explanation for the existence of the cosmos. Aquinas states that if we assume that the series can regress infinitely then we are accepting that things can be ex nihilo and as we know that this is not possible we must find sufficient reason for an initial cause of all other causes, external to our cosmos. A being that is de re necessary and omnipotent, this is what people...