Line of argument:
It is illogical to argue that existence is a predicate as it doesn’t add
anything to the essence of a being.
Paragraph 1:
Anselm’s argument:
Psalm 14: “the fool hath said in his heart there is no God”
God is the greatest possible being that can be conceived, He is
great in all ways
It is better to exist in the mind and reality instead of in the mind
alone
This must mean that God has existence, as a being who exists
would be greater than God which is logically impossible due to the
definition of God
His proof by contradiction relies on this concept of existence being a
predicate
Gaunilo’s criticism
A theoretical island exists, this island is perfect in all conceivable
ways
It is greater to exist in the mind and reality than just the mind
Therefore, the island exists however we know it doesn’t
This shows the illogical nature of the argument; it shows that
existence as a predicate is an inherently flawed argument as
anything can be defined into existence
Descartes developments:
God is defined as a supremely perfect being
Because he is supremely perfect, he possesses all perfections
The perfect state includes the perfection of existence; therefore,
God exists
Existence is to God what a valley is to a mountain, it is impossible to
conceive of a mountain without its neighbouring valley
Therefore, it is illogical to conclude that God doesn’t exist
This argument cannot be applied to objects within time and space
as they cannot be eternal