The ontological argument for the existence of God was devised by St. Anselm of Canterbury, who lived 1033-1106. By philosophical argument, he attempted to prove that the denial of the proposition "God exists" is self-contradictory. It consists of five propositions:
- By the term 'God' is meant a being than which none greater can be conceived
- Whether we affirm or deny the existence of God, a being than which none greater can be conceived exists in the understanding
- It is possible to conceive of a being than which none greater can be conceived existing not only in the understanding but in reality as well; and this is greater
- If, therefore a being than which none greater can be conceived exists only in the understanding, it is not a being than which none greater can be conceived
- Therefore a being than which none greater can be conceived exists also in reality.
Unfortunately, for a number of reasons, it is not a sound argument. The simplest one for a person not educated in philosophy is to replace "the being (God) than which none greater can be conceived" by an island none more beautiful than which can be conceived. This island therefore exists, although in practice we know that it does not.