The Ontological Argument

Anselm( 1033-1109)- Anselm version of the Ontological Argument was originally written as a prayer to praise god. Anselm argument has two forms.

Form 1, Proslogion 2

-P.1 'God is that than which nothing greater can be conceived'.

-P.2  It is one thing to exist in the mind and another to exist in reality.

-P.3 It is greater to exist in reality than in the mind alone. Anselm uses the analogy of the painter and the painting to illustrate his point.

-P.4 If God does not exist then a greater being can be convieved,but this is impossible (reduction ad absurdum)

-P.5 The greater being, God, must therefore exist in reality and not in the mind alone.

Conclusion: God exists in reality.

Form 2, Proslogion 3

-P.1 'God is that than which nothing greater can be conceived.'

-P.2 Everything else can be thought not to exist (contingent)

-P.3 That which has to exist is a greater then that which does not have to exist.

-P.4 A being 'That than which nothing greater can be conceived' cannot cease to exist. ( It much exist)

Conclusion: Therefore God's existence is necessary (logically necessary). So the fool is a fool, because even though he has a concept of God in his understanding he has not taken the next step to realise that the impossibility o such a being is nonsense.

Renes Descartes is in two parts.

First: Descartes believed that our idea of God is innate i.e we are born knowing/ undrstanding God is a perfect necessary being.

Second:             

1. What belongd to the essential nature of something cannot be denied of it

     2. God is a supremely perfect being.

           3. Existence is perfection

             4. God, the supreme perfect being has the characteristic/perfection of 

                 existence.

                   Conclusion: Therfore god necessarily exists (exustence is an

                                       essential feature of God).

Descartes used the analogy of a triangle to explain this. The essential predicate of a triangle is that it has 3 sides and 3 angels that make 180 degrees. If we remove any one of these it ceases to be a triangle. Same for mountains, valleys are a necessary predicate of mountain ranges. So with God, God has the predicate of existence.

- Aquinas rejected the Ontological Argument. He believes that "because we do not know the essence of God the proposition 'God exists' is not self-evident to the human mind only God knows the meaning." If you reject this first premise then the whole argument falls. The human mind can make can make up a definition of the term 'God', and we can say that if that definition is correct, the God necessarily exists. BUT: Do we have the correct definition of the term 'God'? In Aquinas view, we cannot come to know God as He is beyond human understanding, and therefore a priori argument to prove the existence of God fail as we cannot define God. We can only know that God exists through the effects of God's work in world, such as the evidence of desgin in nature.