Examine the ontological argument as presented
by Descartes and responses to it
1.1 The ontological argument, which uses a priori
logic, states that God being defined as most
great or perfect must exist, since a God that
exists is greater than a God who does not. St.
Anselm of Canterbury proposed the first
version in the second chapter of his
Proslogion in which he stated 'God is that,
than which nothing greater can be conceived.
2 'SUPREMELY PERFECT BEING'
2.1 Rene Descartes proposed another version after Anselm, for the existence
of God based on perfection as a necessary attribute of God. He defined God
as a 'supremely perfect being' with omnipotence and omniscience and
claimed that a perfect being must exist in order to be perfect. Therefore
existence is a perfection that God cannot lack, and so his existence is
necessary and he must exist. He claimed as an imperfect being, he could
not have made up this definition. His argument is focused on a conceptual
basis as it starts with the idea of God and so even the atheist must accept is
as it would be illogical not to do so.
3 GOD POSSESS ALL PERFECTIONS -
EXISTENCE IS A PERFECTION - GOD
3.1 Descartes guarded against the attack Gaunilo developed against Anselm by
saying that 'God possess' all perfections', the argument applies only to an
absolutely perfect and only necessary being, it cannot therefore be applied to
something like a lost island. His second premise was that 'existence is a
perfection', not everyone thinks of God, but if they do then God cannot be
'thought' to exist and instead he must, linking him to the concept of perfection.
From this he deduced that God must exist, as a 'supremely perfect being' must
possess the perfection of existence. God alone is the being who entails God's
essence, there cannot be 2 or more such beings. Because we can know God's
essence, we can say he exists.
4 ANALOGY OF A TRIANGLE
4.1 To illustrate his view, Descartes argued that the essence of a triangle is a '3
sided plane figure' and all the internal angles add up to 180 degrees. A
triangle must maintain these predicates in order to be classified as a triangle.
To say that God does not exist, is like saying a triangle does not have 3 sides
or the internal angles do not add up to 180. In the same way, existence
cannot be separated from the concept of God and therefore is a predicate of
God. From this he concluded God is a necessary being and is
non-contingent and claimed his argument is proof that 'God cannot not exist'
5 RESPONSE: CATERUS
5.1 A priest called Caterus responded to Descartes argument. He
argued using the statement 'If God exists then he is the highest
being', emphasizing the word 'if'. He said it was not illogical to say
'God does not exist therefore there is no highest being'. All
Descartes is establishing is that if there is a triangle then it must
have 3 sides, it does not actually mean there are any triangles. If
there is a God, God must exist but the problem is 'if'. All this
concludes is a statement about triangles. It is equally coherent to
say 'triangles do not exist therefore 3-sided plane figures do not
exist'. Likewise, we might say unicorns have one horn but that
does not mean they exist.
6 RESPONSE: KANT
6.1 Until recently, most scholars rejected Descartes argument in
favour of Kant. Kant thought he made an illegitimate jump from
ideas to reality. He said we may not be able to rejected the idea of
a triangle with 3 sides but we can reject the triangle all together.
Descartes argued that God has existence in the same way a
triangle has 3 sides but if you do not have a triangle you neither
have its 3 sides or 3 angles. If you accept that there is a God it
would be illogical to accept his existence as necessary, but you
don't have to accept there is a God at all.
7 RESPONSE: AQUINAS
7.1 Thomas Aquinas stated that we cannot argue
from knowledge of essence of something, even
God to the conclusion that he exists. He believed
that to define something implies that we have an
understanding of it, but we as weak limited human
beings have no way of knowing if our definition of
him is correct because he is beyond our
understanding. 'A supremely perfect being' is not
a meaningful concept as it does not have a
maximum. With numbers, you can never come to
an end as you can add to them, in the same way
perfection can be added to.