Discuss whether the ontological argument would convince an atheist

Another prominent criticism of the ontological argument which suggests that it would not convince an atheist is from Thomas Aquinas (1225-74) who is argued to be the greatest of the medieval philosophers and theologians.  Aquinas showed that the ontological argument would not convince an atheist by arguing that is not impossible to have the mental concept of the non existence of God, because people quite clearly manage it, including the fool who says in his heart ‘There is no God’. If we can imagine a state of godlessness, then it cannot be a contradiction in terms, despite Anselm’s claim in the ontological argument. Aquinas also went on to question one of the premises of the ontological argument’s syllogism that God is ‘that than which nothing greater can be conceived’ (aliquid quo nihil cogitari posit). Aquinas believed that although we can approach an understanding and awareness of God, God will always remain unknowable to the finite human mind. Furthermore Aquinas went on to reveal more weaknesses in the ontological argument which proves that it is unlikely to convince an atheist by arguing that the concept of a God as ‘that than which nothing greater can be conceived’ even if universally shared, doesn’t indicate that such a being existed in reality.

A final criticism of the ontological argument which many believe finally demolished such arguments as a tool to convince atheists is from Kant. Kant argued that ‘existence is not a predicate’ as it does not tell us anything about the object that would help to identify it in away. Kant stated that whatever concept we have of God, whether it is as Anselm’s ‘that than which nothing greater can be conceived’ or Descartes ‘sum of all perfections, this concept cannot simply be actualized by adding ‘existence’ to its predicates. Kant used the analogy of a triangle to explain this criticism. He declared that we can predicate of a triangle that has three sides, and that its angles add up to 180 degrees, but we would have to investigate to find out whether the triangle in our minds has been actualized. One response to Kant’s criticisms which shows that the ontological argument may have a chance of convincing an atheist is that God’s existence is different to the existence of anything else. Other things exist contingently whereas God exists necessarily. This argument, however, is unlikely to impress an atheist, as it makes the ontological argument circular in that the atheist has to originally accept that God exists necessarily in order to come to the conclusion that God exists necessarily.

Overall despite the ontological arguments uniqueness as an a priori argument for the existence of God, it is to a large extent still highly unlikely to convince an atheist. This is mainly because as Gaunilo stated if we replace God with an island we can see how the argument falls, and also because of points by Aquinas and Kant that it is possible to have a mental image of a Godless world and that existence is not a predicate.