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 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. Bananas are yellow Rhinos have horns Giraffes have long necks Snowflakes melt God is angry God exists

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

Some tame tigers do not growl Some tame tigers do not exist 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.

Cows are brown and exist 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… Men exist SantaClaus is a man 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 (spacio-temporal) world