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 HornIt 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 hornsSame 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

• 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.

G.E. Moore

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

If we are to talk about something existing, we need to find evidence for it in the real (spacio-temporal) world

Syllogism