Criticisms of the Ontological
Argument
Thomas Aquinas, Immanuel
Kant, David Hume, GE Moore
Bertrand Russell
Aquinas
• Human reason is fallible
• We cannot fully comprehend
God – God is beyond human
understanding
• A Priori knowledge is
inadequate for gaining
knowledge of God
• Proof of God’s existence must
come from inductive
arguments based on A
Posteriori knowledge
Predicates?
•
•
•
•
•
•
Bananas are yellow
Rhinos have horns
Giraffes have long necks
Snowflakes melt
God is angry
God exists
Kant claimed that a
predicate tells us
something about
the subject – it adds
to our idea of what
the subject is like.
To say “God exists”
tells us nothing
about God whereas
God is angry does.
Kant’s Objection
“existence is not a predicate” - it is not
the same as red, green, large, small, happy, sad
While it is impossible to separate subject from predicate
in analytic statements,
Unicorn
Horn
It is possible to deny the existence of both the subject &
the predicate.
The most we can infer is that if unicorns exist, they
necessarily have horns
Same is true of God: if there is a God, he necessarily
exists.
David Hume
• Hume is an empiricist
• ‘Knowledge’ must be provable
using scientific methods
• Evidence is needed to back up
claims
• No such thing as “necessary”
existence – everything that
exists is contingent.
• He also said existence is not a
predicate
G.E. Moore
• Some tame tigers do not growl
• Some tame tigers do not exist
• GE Moore reinforced what Kant
argued
• “Existence” does not work in the
same way as other predicates.
• “Existence” is a term used to refer
to things existing in the universe.
Bertrand Russell
• The term “existence” refers to something which
exists in the spacio-temporal world
• Cows are brown
• Cows are brown and exist
• The second statement tells us nothing more than
the 1st statement.
• “existence” is not part of the description of a
thing – it is an indication of its extension to reality.
• Whether dragons exist or not has no impact on
my idea of what a dragon is
Russell cont…
• The grammatical structure of a statement
does not indicate its validity.
• Men exist
• SantaClaus is a man
• Therefore Santa Claus exists
Syllogism
If we are to talk about something existing, we
need to find evidence for it in the real (spaciotemporal) world