The transition from the first conclusion of the universe having a cause and the cause being God has been received rather negatively, as even if we were to accept the argument hitherto, then it would not be explicitly obvious that it was indicating to the God of classical theism. We could posit another being there as its cause, as there is no evidence pointing to the God of classical theism. However it could be argued, that everything is a product of its context and Al-Ghazali wrote this to reinforce faith and belief to readers he assumed to be similar to him in some ways, and so would accept the God of classical theism as the cause, and by taking his argument out of context is rather unfair and unreasonable to Al-Ghazali. Furthermore, he makes an epistemological assumption in his second premise, which states that the universe began to exist, however how do we reliably know that the universe began to exist, as there was no one around to experience such a thing, also an good empiricist like David Hume would say, this takes us beyond experience, therefore being unreliable. But the universe having a beginning has support from modern science, as the Big Bang claims that the universe began to exist from a single starting point, although the Big Bang and the cosmological argument may not be exactly reconcilable with each other, the point of the universe having a beginning is a shared principle. It is noteworthy to point out that the concept of causation has been criticised by philosophers such as Hume as a concept that is imposed upon the world by the human and does not exist in reality. The first premise of everything having a cause is challenged by quantum physics which states that on a quantum levels things come into existence without a cause, however it should be mentioned that just because something happens on a minute level does not mean it will happen on a grand universal scope. Al-Ghazali probably was not expecting his arguments to be scrutinised a thousand years later and be took out of its context, however its weaknesses are evident and overshadow the strengths.
Saint Thomas Aquinas was a scholastic philosopher who sought greatly to prove the existence of God; in his Summa Theologica he presents many ways to prove the existence of God. He ventures to do so, first by arguing from the concepts of: causation and motion. These are features of the universe that we all experience, as Aquinas would claim, and he considers the possibility of motion and causation to have always existed, however he then goes on to employ a reductio ad absurdum, to expose the ridiculousness of such a notion. His argument from motion first considers that there are things which undertake or in a state of change, such as wood burning in a fire, he then says that nothing can move or change itself, like Plato said, everything is a secondary mover. He then proposes a notion that does not require a God or first mover and then reduces it to absurdity, as he goes on to say, conceive of a universe were everything was a secondary mover, which would result in an infinite regress of movers, and so if this were true then would be no primary mover, thus no subsequent movers, but this is false; therefore there must be an unmoved prime mover which is the foundation of all motion and change whom we call God. His argument from causation follows the same route of reasoning, as first he claims that every event has a cause, and goes to claim that nothing can be the cause of its self. Then he says conceptualise of an order of causes which goes back infinitely with no first cause, which he goes on to reduces to absurdity by claiming that if that were true then there would be no consequent causes, but he claims this is false; therefore there must be a first cause which is the groundwork for all causes, whom we call God.
These arguments have conspicuous weaknesses which greatly undermine and abate the argument. Firstly both of the arguments in some way rest upon a contradiction, in that Aquinas says that everything must have a cause as ex nihilo nihil fit, nothing comes from nothing, but then concludes that something must exist that can be the cause of itself, this is quite a glaring contradiction, but this is precisely what Aquinas utilises the reductio ad absurdum to do, to show that if there was not a self-causing first cause then it would lead to an infinite regress, which is not possible, and that God is a special being which can be reasonably posited and is the exception to the aforementioned rule. However if we are acquiescing to exceptions, why make the God of classical theism the exception, is it not more reasonable to make the universe the exception to this ‘rule’, and then we could conclude that the universe just is and has no cause but caused itself, and there would be no need to postulate the need for a God. As Hume said “It were better, therefore, never to look beyond the present material world.”, so seeking explanations that go beyond the peripheries of the physical world will only lead to infinite regresses, and that we which should either: accept no explanation or find an explanation within the universe itself.
Aquinas makes an ontological assumption on the concept of causation, which were later greatly criticised by Hume. As he claims that as we have no experience of causation, it is likely to be something our minds imposes upon the external world, for example, the white snooker ball does not cause the red ball to be pocketed but in actuality the white ball moves towards the red ball until they touch and then the red ball moves away into a pocket. Hume would claim that it is our minds which require us to say that the white ball causes the red ball to be pocketed. If he were to be right then this would undermine the argument immensely. However some philosophers like Elizabeth Anscombe would argue that even if it is not the balls that cause each other to be pocketed but rather magnets, it is still impossible for us to genuinely believe that there was no cause, and Hume was being unreasonably sceptical. Furthermore cause usually has some purpose behind it; however we cannot seem to find a universal purpose that everyone accepts, as the purposes that religion gives are clearly not universal as only adherents of that religion have them. If the universe did have a purpose, would we not be able to deduct what it was, like how we can tell the purpose of a hammer by observation. Also an existentialist philosopher or an absurdist philosopher like Albert Camus would claim that the universe has no purpose and we create and impose upon the world our purposes; in reality the world is meaningless and absurd, if this is true then it would greatly undermine the argument.
The most profound weakness is the ‘Fallacy of composition’, which is the misconception of thinking that there is a property or predicate to each part of a given group, it must be logically follow that the whole group has the same properties or predicates. As Hume would say if we have explained each cause in a series, it is unreasonable to ask what the cause of the series as a whole is. Bertrand Russell highlights this point greatly with his example of human beings and mothers. It is true that every human being has a mother, but it is a fallacy to apply to this to the whole race of human beings, and claim that the human beings as whole have a mother; it is unreasonable to move from individual causes to causes of totality. If this is right, then Aquinas’ argument is undermined as he is wrong to claim that a first cause started the chain and the cosmological argument fails.
Aquinas presents a further version of the cosmological argument; the argument from contingency. He claims that all contingent beings like humans, have a shelf life or a definite period of time for their existence, and they will cease to exist at some time. These all depend upon something else to exist. But if everything were to be contingent, then there would be a time when everything would pass out of existence, but Aquinas utilising his reductio ad absurdum, claims that if the previous statement were true, then there we would be nothing but there is, meaning that that is false. This first part of his argument concludes that everything cannot be contingent and there needs to be necessary being. He then goes on to say that necessary things either have their cause of necessity in itself or outside of it, dependent on something else. If it were true that every necessary thing has their cause outside themselves, then there would be no ultimate cause of necessity; therefore there must be a necessary being which causes and sustains all contingent and necessary things, which we call God. This God not only creates the universe but also sustains it, as contingent beings require a necessary being to maintain and preserve them. This is called the efficient cause, the cause that keeps the given subject going.
Aquinas here does not seem to consider the possibility of an infinite series of contingent things which overlap each other, as J.L Mackie pointed out and so if this were to be the case then there is no need to postulate the existence of a necessary being. The most abject criticism is how Aquinas is assuming that necessary beings exist, and that he does not in fact understand how necessity applies only to truths that if they were to be denied then it would result in a contradiction, and as Hume and Kant highlighted There can only be necessary propositions such as bachelors are unmarried men, because if we were to deny it and say that for example bachelors are married men, then we would be committing a contradiction. But claims about being can always be denied; like for example Socrates once existed and God exists can both be denied without resulting in a contradiction. If this is true then Aquinas’ assumption is wrong and therefore God cannot be the necessary being and his argument is undermined greatly.
Modern science poses a formidable challenge to cosmological arguments, as the Big Bang theory, formulates a reasonable course of action, whereby all matter was concentrated at a single point and then it exploded and is still expanding. This greatly opposes the idea of God being the creator and the efficient cause, removing the need for God. Some would argue that as the Big Bang did not ‘exactly’ cause the universe but was the first thing inside the universe, so it cannot be an adequate explanation. However the concept of causation is contingent to the concept of time and if one were to ask what caused or what was before the Big Bang, then that would be nonsensical as the Big Bang is the beginning of time and how could anything precede time, to have before and after, you require time. Therefore modern science poses a big challenge for cosmological arguments, as it undermines the claim that God is the cause of the universe.
In conclusion, the cosmological argument does have its strengths, as evidently it has stood the test of time, from Aristotle living around two thousand three hundred years ago, to being revived by Aquinas and Al-Ghazali around a thousand years ago up until the present day and age, requires one to acknowledge that it is an interesting and respectable argument. Also it seems to be quite universal, as philosophers of different religions have used it; Aristotle being a Pagan, Aquinas a Christian and Al-Ghazali a Muslim manifests this. However as it is rather evident many of them rest on unreliable foundations and expose themselves to many criticisms, overall the weaknesses outweigh and overshadow the meagre strengths. Even so, if it were to succeed in proving the existence of a first cause, it never goes to show us why such a being would be worthy of worship. Ultimately it does not prove the existence of God.