Trying to prove that God exists is a difficult argument and many people have tried many different ways. The Ontological argument is one argument; at the centre of the argument is the concept of existence. The Ontological argument has been argued from a group of philosophers for the existence of God. “Ontological” means talking about being and so that being is the existence of God. The ontological argument differs from other arguments in favour of God because of the fact that it is an a priori deductive argument.
There are two main arguments for the ontological argument which seeks to prove the existence of God a priori. The first argument is from Anselm; he was the Archbishop of Canterbury and therefore started his argument from a theistic point of view. Anselm believed that no belief in God was absurd and he used a reducio ad absurdum argument, which tries to show that God not existing could not be believed because in not believing you are adopting a nonsensical argument. His starting point was his definition of God, ‘God is the thought than which nothing greater can be conceived’.
Firstly Anselm attacks the idea that there is no God, even the thought that there is no God requires the concept of God. The greatest possible being has to exist in reality as well as in the mind to be the greatest possible being therefore we can conceive of the greatest possible being because it also has to exist in reality. A criticism that was raised about the greatest possible being is that we as humans all have different ideas of what it could be but Anselm responded by saying that when we reach the idea of such a high level being such as God then the idea of what it is becomes very similar.
Therefore God exists according to Anselm. Also God is considered to be a necessary being, which will always exist, does not rely on other beings and cannot not exist, therefore God must exist if he is to be called a necessary being. The second philosopher to argue the existence of God using the ontological argument was Rene Descartes; he set out his argument firstly by defining God as ‘a supremely perfect being’. From this he tried to prove the existence of God, because God is defined as a supremely perfect being he possess all perfections.
According to Descartes the perfect state includes existence as well as the classical attributes of God, he believed that existence was perfection in itself and therefore God must exist. Therefore this is why we as humans cannot have a necessary existence because we do not have complete perfection. Descartes used mathematics and an example of a mountain with a valley to explain that God must exist, the mountain being separate from the valley and according to him it is the same with God, you cannot separate existence from God.
This argument however cannot apply to objects affected by space and time, contingent things and can only apply to necessary beings which are perfect. He continues by saying that only God can have absolute perfection and there can only be one absolute. Descartes goes on to point out that Mackie or Russell are trying to establish necessary existence of contingent objects such as unicorns but necessary existence only applies to absolutely perfect beings.
A criticism of the argument was put forward by Thomas Aquinas, who had already questioned the important aspect of the ontological argument, the idea that we cannot assign existence a priori to our definition of the idea of a perfect being. Aquinas claimed Anselm was guilty of making a ‘transitional error’, moving from his definition of God to the claim that he exists. Anselm also made the assumption that his definition was shared by all believers of God. The meaning of the term God means he exists in peoples understanding but not in reality.
According to Aquinas the existence of God must be shown a posteriori which is what he tried to attempt to show in his cosmological argument. Also David Hume disagrees with the ontological argument. Hume was an empiricist so disapproves the use of a priori to prove existence and believes it should only be used for a definition. A description of a thing can contain every detail possible but we have to go beyond a description to be able to determine its existence, just because we can describe it does not mean it therefore pops into existence.
He believed the only way in which you could prove something a priori was if the opposite implies a contradiction, such as x=not x. Therefore if it implies a contraction then it is inconceivable and then everything can be conceived not to exist. Therefore Hume’s believed that nothing can be proven to exist a priori, including God. He came to the conclusion that existence could only ever be contingent. Kant also disagrees with Descartes ontological argument. He used the example of a triangle, if you have a triangle it must have three angles but if you do not have a triangle it will not have three angles.
It all depends on whether you agree there is a God or not, if there is a God then his existence is necessary but we do not have to accept the idea there is a God. Descartes according to Kant just gives God existence, however existence isn’t a property. God could have all the classic attributes but still he might not exist. For example a chair, it has many properties which are established a posteriori but whether it exists or not have to be discovered a priori. Using Descartes idea but changing it slightly, “existence is not predicate”.
By adding reality to something does not mean it makes it better, Kant’s example, “a hundred real thalers does not contain the least coin more than a hundred possible thalers”. We must establish whether something exists or not before we can describe it, not the other way around and therefore if there is a perfect being then he must exist. Kant distinguishes between a priori and a posteriori, a priori are necessary, they have to be so whereas a posteriori can be challenged, such as how many people you think you saw.
If something exists and the existence of that tells us about its property then by saying it does not exist you deny it of that property and almost say that it lacks it, however how can you say that something that does not exist lack something? This is a strong argument against the ontological argument which cannot be explained easily. A criticism of Anselm’s ontological argument directly was from Gaunilo, he had the same idea as Kant, that something cannot be defined into existence.
Just because we define what we believe God to be does not mean that he actually exists. In Gaunilo’s book ‘On behalf of the Fool’, he describes the Lost Island as the greatest possible island and that no greater island can be conceived. It is logical to say that it is greater to exist in reality than as just an idea. If this island therefore did not exist there could be a even greater island which did exist and so therefore the Lost Island must exist somewhere.
The perfect island exists but it may not be what you think of as the perfect island because by imaging it does not mean it exists. Therefore Anselm saying that God the perfect being had to exist cannot work. However, there is a problem with Gaunilo’s criticism, Anselm said he was not arguing about contingent things such as the island which have no intrinsic maximum, he was arguing for the ‘greatest thing that can be conceived’ which has a intrinsic maximum and so can be perfect.
Therefore the ontological argument can be used to talk about such things as God which is necessary but cannot be used when talking about contingent things such as an island. The island is limited whereas the notion of God is not. To conclude, to prove the existence of God a priori we need to have knowledge of what God is, before sense experience can be gathered. This is where the ontological argument falls down. How can we understand a being when we cannot see, hear or touch them first if we want to prove the existence using a priori.
A priori uses facts which are either true or false to determine things but without ever experiencing God ourselves through a posteriori first we have no facts in which to use a priori. The only way in which we can argue that God exists is if we treat him as if he were an object. God existence is reality in the believer’s world but for someone who is atheistic then he does not. I agree with Norman Malcolm who argued that necessary existence cannot be affected by anything external to itself. It cannot be created or destroyed, therefore God either exists or his existence is impossible.
Therefore I believe that he cannot exist because something would have had to bring him into existence at the beginning which therefore means he cannot be a necessary being because he would have always had to exist but there must have been a point when he didn’t. Also if he is a necessary being with all the classical attributes why is the evil and suffering and if he was omnipotent then why does he want to hide himself from us? If he has power in which to be able to show himself then why has he not and then we would be able to prove his existence using a posteriori instead of a priori.