Wednesday, 6 November 2013

The Cosmological Argument for God's Existence

a.) Explain Aquinas’ First 3 ways

St Thomas Aquinas, a 13th Century Italian philosopher, is to philosophy what Gerard Manley Hopkins is to poetry; well renowned for his scholastic works, a significant amount of modern theology is a development of Aquinas’ ideas. His Cosmological Argument is taken from the first three of ‘The Five Ways’ in his major (although unfinished) work, Summa Theologica. The philosopher William Lane Craig supported Aquinas’ Cosmological Argument, saying: ‘Transcending the entire universe there exists a cause which brought the universe into being…’ Aquinas’ argument is empirical (looking at the world), and uses the a posteriori method (using experience to come to a conclusion). It is also an example of natural theology, rather than revealed theology, as it uses logic and reason to study God.

Ancient philosophy (Cicero and Aristotle particularly) had a huge amount of influence of Aquinas’ ideas, and indeed many of Aquinas’ philosophies are synonymous with those of Aristotle. For example, the idea of ‘The Unmoved Mover’, and the idea of ‘motion’ (movement from potentiality to actuality), can be directly associated with Aristotle’s ‘Prime Mover’.

The First Way, The Argument of the Unmoved Mover (‘ex motu’), or The Argument of Motion, tries to explain that God is the cause of all motion in the universe. It states that ‘some things are in motion’ according to our senses and what we see in the natural world. Aquinas then goes on to explain that everything that is in motion has been moved by something else (‘whatever is in motion is put in motion by another’), and that nothing can move itself. According to our senses, this is all true – in our world, all motion has a mover. However, this idea creates a problem for Aquinas – if everything has a mover, then this system would go on infinitely, as nothing can move itself. Aquinas then states that ‘this cannot go on to infinity, as then there would be no first mover, and, consequently, no other mover.’ He is saying that without a first mover there would be no movement whatsoever and so the world would not exist. He then concludes that there must be something that caused itself, which he calls the ‘first mover’, whom he then claims is God. By using empirical knowledge, and by ruling out the possibility of infinite regress, Aquinas is able to come to the logical conclusion that there must have been a beginning for all movement – the First Mover.

The Second Way is known as The Argument of the First Cause (‘ex causa’), and is the shortest of the three ways – it is also rather similar to the first way. Aquinas explains that all efficient causes go in an order – the first being the cause of the intermediate cause, and the intermediate cause (or causes) being the cause of the ultimate cause (i.e. the final cause of an object). Again, in this argument Aquinas uses empirical evidence, and in fact he begins by saying: ‘In a world of sense…’

In his Second Way, Aquinas is trying to prove that God is the creator of our Universe. Aquinas starts by stating that everything that happens is caused by an efficient cause, and that nothing can cause itself (‘There is no case known… in which a thing is found to be the efficient cause of itself;’) Again, he then states that infinite regress (the idea that cause and effect goes on for infinity) is not possible because this would mean that there is no ‘first cause among efficient causes’ – if so, there would also be no ultimate or intermediate causes, which we know is not true (‘all of which is plainly false’). He then says that there must be a first cause, which he says caused itself, and is therefore God.

Finally, The Third Way, also known as The Argument from Contingency (‘ex contingentia’), is rather different from the first two ways, in that it does not put as much emphasis on the idea of cause and effect. Instead, it focuses more on contingent things (things subject to cause and effect) and necessary things (things that cannot not exist). Aquinas begins by stating that our universe is full of contingent  things, but that it is impossible for everything to be contingent, because then at one point nothing would have existed (‘then at one time there could have been nothing in existence.’) This is impossible because ‘creatio ex nihilo’ is impossible, unless (as Aquinas states clearly) there is a necessary being, which has always existed, which created or caused all of these other, contingent beings. He then says: ‘This all men speak of as God.’ What Aquinas is saying is that there must be a necessary being (or a supernatural being) that created something, because otherwise nothing at all would be here. Without the necessary being, we question where the first contingent thing came from? He argues that a supernatural God is consistent with empirical evidence of the laws of nature i.e. that nothing comes from nothing.

The Five Ways were not intended by Aquinas to prove God’s existence, but rather to teach us more about the nature of God.

b.) ‘Aquinas’ Cosmological Argument provides a strong argument for the existence of God.’ Discuss

Aquinas’ Cosmological Argument, consisting of three different parts (from his work Summa Theologica), is not a strong argument for the existence of God.

Many claim that one of the flaws of Aquinas’ argument is his use of inductive reasoning. Although this strongly appeals to us, it is not necessarily right, and is based primarily on probability, and also his own assumptions. Hume argues that Aquinas presents his statements as deductive or analytic statements (e.g. ‘Whatever is in motion is put in motion by another’ is in the form of a fact), when in fact they are synthetic statements (statements which must be proven, and are not true in themselves). This is a huge flaw because Aquinas doesn’t prove these synthetic statements, but instead just insists that they are true.

However, Aquinas’ argument is very compelling, simply because it is completely logical. It uses empirical knowledge and reason, along with the a posteriori method, therefore appealing to our senses and experience – this means that it is natural to us and agrees with what we know and see in our world.

But this is not always a positive – just because we experience something in our own world, this does not necessarily mean that it is true of the entire universe. Criticising Ways 1 and 2, David Hume and Bertram Russell both argued that we do not know that the universe itself is contingent (and therefore needs to be created), and that it could in fact be necessary, and therefore eternal. They claim that we do not know that the universe needs a cause, saying that Aquinas is only making the assumption that it does. This is known as ‘The Fallacy of Composition’, and Bertram Russell is famously quoted: ‘Obviously the human race hasn’t a mother.’ He said that just because all people have a mother, this doesn’t mean the universe also has one.

Another flaw of the Cosmological argument, which Hume pointed out, is that we do not know that the principle of causation is true (i.e. we do not know that every effect has a cause), although it is human nature to assume it. One can use the example of an alien on earth seeing somebody put their hand out for a bus, and the bus stopping. This alien would assume that the direct cause of the bus stopping was the hand, although this is clearly false. Hume once said: ‘We shall find upon examination, that every demonstration which has been produced for the necessity of a cause, is fallacious and sophistical.’ Hume argued that because we can imagine (in our minds) something coming into existence without a cause (‘It is easy for us to conceive of any object to be non-existent this moment, and existent the next, without conjoining to it the distinct idea of a cause…’), then it is perfectly possible.

However, many would argue that everything in the universe does have a cause, and although it is impossible to prove, it is a completely sensible conclusion to come to. From the experience (and this is what Aquinas’ argument was based on) of our natural world, we understand that every effect has a cause, and this is one of the most common maxims in philosophy - it is indeed very brave of Hume to reject it.

Nonetheless, it is an undeniable flaw of Aquinas’ argument, and Hume then expands on it by saying that a self-causing cause is illogical. He claims that Aquinas is being ridiculous by saying that everything needs a cause, but then claiming that God doesn’t need one – this would ‘exclude the thing itself’.

J.M Mackie argued that Aquinas’ Argument from Contingency doesn’t fully explain the need for a necessary being (i.e. God). Both Kant and Mackie said that just because we can imagine God as an ideal, this does not make him a particular. To say that existence is a predicate of God, because existence is a characteristic of perfection, is a synthetic statement, and without any proof, is unsatisfactory. Mackie expanded this argument by saying that, even if there is need for a necessary being, then there could just be a necessary ‘stock of matter whose essence did not involve existence from anything else.’ He strongly criticises Aquinas for making an ‘inductive leap’ (Hume) and concluding that any necessary being must be God.

However, it is true that many people at the time of Aquinas would have been Christian, and would have believed in God, and so for them this would have presented itself as a strong argument. Also, as science was particularly primitive in that period, any sort of empirical arguments would have been extremely convincing. Furthermore, this argument is strong in the context of the modern day too, simply because it can link with the Big Bang, the most common creation belief.

Nonetheless, it is a clear flaw that Aquinas does not attempt to prove that this necessary being must be God. It is also a weak argument because he does not look at any other possibility of creation, but because he is a Christian, he just assumes that God is real, making the argument weak for atheists. He also doesn’t necessarily explain why infinite regress is impossible, and this is another example of Aquinas’ inductive leaps.

Overall, I think Aquinas’ argument is weak, because he does not prove all of the things that he says, and it is hard to believe from the perspective of an atheist simply because it is constructed with a biased point of view. Aquinas’ overuse of synthetic statements and assumptions, along with the strength of ‘The Fallacy of Composition’, show the argument to be particularly flawed.


  1. Excellent stuff Tom. I'd say that your latter arguments - that the attempt to prove god's existence comes from a desire to believe that he exists - informs pretty much all pro-god arguments, but perhaps that's me.

    Quantum physics has pretty much disproved Aquinas' third way, and possibly the other two. At the quantum level, particles come into existence and disappear all the time, with no cause or trigger whatsoever. These are called quantum fluctuations. It is believed that they may explain many things, perhaps most importantly, the reason why the matter in the universe is concentrated in small clumps - stars, galaxies, planets etc. - instead of being completely uniformly distributed, as it was in its very early phases (in which case the entire universe would be a single "object", rather than a space that contains them).

  2. Sorry, I meant to say your latter point *applies* to all pro-god arguments.

  3. Yes, I agree - this is a particularly important point to make when talking about Aquinas because he wasn't even trying to prove God's existence, only to explain his existence to Christians - thus it is a weak argument. And yes, we have just been learning about Russell's responses to Copleston's Cosmological Argument, which include Quantum Fluctuations etc. etc.