Definition: The Ontological Argument, which
uses a priori logic, states that God, being
defined as most great or perfect must exist,
since a God who exists is greater than a God
who does not.
It is widely accepted that St. Anselm of Canterbury
proposed the first ontological argument in which he
declared 'GOD IS THAT, THAN WHICH NOTHING
GREATER CAN BE CONCIEVED'
ANSELM & GAUNILO
According to Anselm, to simply
conceive of a God who is the
'Greatest Conceivable Being', is to
inherently acknowledge its own
existence. His first premise states
'The Greatest Conceivable Being
exists only in the mind and not reality'
This quote means that one is simply using their imagination to think
of something that does not exist in real life. Here he demonstrates
that even a fool would acknowledge the existence of the Greatest
Conceivable Being in his mind, as he must to take part in the whole
argument, therefore God does exist.
Gaunilo uses a philosophical device known as reducto ad
absurdum. He sets up a parallel argument for the critique of the
ontological argument; removing the word 'being' from Anselm's
premise of 'The Greatest Conceivable Being' and substitutes it for
the greatest conceivable island.
He asserts that if this island was the greatest
conceivable island then it would take on qualities similar
to those of God such as omnipotence and omniscience.
The perfect island is the island which no greater can be
conceived and any island that does not exist cannot be
the island than which no greater can be conceived, for it
could be conceived to exist which would be greater.
Anyone who thinks
that the perfect
island does not exist
is confused; the
concept entails that
there is such a thing.
The fact that there is
no perfect island,
then shows that the
ontological
argument for God's
existence is flawed.
KANT
Existence is not a predicate (a property that a thing can
either possess or lack). When someone asserts God exists,
they are not saying there is a God and possess' the property
of existence. If it was the case, they would be saying there is
a God and he lacks the property of existence- affirming and
denying his existence in the same breadth
He suggests instead to say
something exists is to say the concept
of it is exemplified in the world,
existence is not a thing possessing
property, it is a concept relating to the
world. It is now possible to compare a
God that exists and a God that does
not as existence is not a property of objects
A God that exists and a God that does not are
qualitatively identical. A God that exists is
omnipotent, benevolant, omniscient, both are the
same. Anselm's claim that an existent God is
greater than a non-existent God is false- neither is
greater than the other- OA fails
HUME
Hume's Dialogues Concerning Natural Religion contains
argument against proof of a priori of God's existence. Presented
by character Cleanthes. Claims only way to prove a priori is if the
opposite implies a contradiction. If something implies a
contradiction it is inconceivable, everything can be conceived to
exist so nothing can be proved a priori
To find out whether a statement can be proved a priori, we imagine
that it is false. Hume took the statement 'an equilateral triangle has
three sides of equal length' and asserted it cannot be imagined
false as a triangle MUST have these properties to be a triangle. If
we imagine it false, then it cannot be proved a priori, empirical
observation would be needed therefore it is a posteriori argument
To find out whether God is
necessary, we must try to imagine
he doesn't exist, as we are able to
do so, his non-existence is
possible. No abstract reasoning
could establish his existence
because only necessary truths can
be proved a priori. The
conceivability of God's
non-existence shows that his
existence isn't possible
DESCARTES
AQUINAS
We can't argue from knowledge of essence of
something, including God. It exists only as a mental
being. He rejected reducto ad absurdum arguments.
We as weak limited humans cannot have such a
clear understanding of God to allow us to believe
'God does not exist' is a contradiction