Ontological argument

• Anselm's version of the ontological argument involves defining God as "that than which nothing greater can be conceived."
• The ontological argument is an attempt to prove the existence of God through reason alone, without relying on empirical evidence or religious texts.
• Arguments for the existence of God are logical
• A deductive argument: if the premises are correct then the conclusion must be true
• A priori is based on understanding and knowledge, not experience.
• “God exists” is an analytical statement and based on definition
• Anselm: A proof by contradiction

  1. god is something than which nothing can be greater thought of
  2. things exist either in the mind only or mind in reality
  3. it is greater to exist in mind reality than in mind only
• Therefore, Anselm means that is not something than which no thing greater can be thought of.


  But P1 says God is something than which no ting greater can be thought of

  These 2 statements form a logical contradiction, our assumption (God exists in mind only) is false

  By P2 the alternative is God exists in mind reality
• Anselm’s second argument

  1. God is something which nothing can be greater thought of
  2. Things either exists contingently or necessarily
  3. It is greater to exists contingently or necessarily
• “I think therefore I am.”


  Descartes says this, the quote means intelligent, belief and real.
• Background to Descartes‘ argument

  1. God has placed in every person the idea of him can’t doubt the existence of God
  2. Demonstrating the existence of God is by showing no doubt that he exists.
• Descarte’s believes that because humans have the idea of a perfect being, therefore God exists.
• Descartes

  • God= Supremely Perfect
  • Something supremely perfect must exist to be perfect
  • Therefore God exists
• Descartes 


  A perfect person only exists because of law because triangles triangles have 3 sides God exists because its analytical
• Malcolm

  • Supports Descartes and Anselm and he proposed another argumeny
  • If God could exist, he does exist, sine he cannot not exist.
  • God’s existence is either necessary or impossible, but that he cannot possess contingent existent.
• Plantiga

  • We are able to imagine any number of alternative worlds
  • So God must exist in one of them
• Plantiga

  1. There exists a world in which there is a being of maximal greatness
  2. A being of maximal excellence is omnipotent, omniscient and amnibenevolent in all worlds.
  3. This argument is only successful in showing that God is a possible worlds, not that he is actually possible in all worlds
• A synthetic argument- Usually refers to a proposition or statement the truth or falsity of which have to be verified. Synthetic propositions are not intrinsic to the subject of proposition. (e.g the car is green, this may or may not be true)
• Analytic arguement- A proposition or statement that is incoherent to doubt, (e.g triangles have three sides.)
• Cons for the ontological argument

  • No agreed definition of God
  • Existence is not a predicate
  • Logical thinking
• Challenges: Hume

  • We cannot treat existence as a predicate that something can have or not have.
  • Adding existence to something does not change its definition
  • “God exists” is a synthetic statement.
  • its not analytic as ‘God’ does not contain the idea of existence
• Challenge: Aquinas

  • God is beyond human understanding
  • Cosmological and Ontological arguments are a priori argument's
  • Supreme blessedness or happiness. We naturally desire happiness and what it means to us, this doesn’t mean God exists.
  • No human can have a correct understanding of God, he is beyond human understanding
• Challenge: Kant

  • Even if existence is a necessary property of God, does not mean he exist.
  • Existence is not a property of anything
  • Even if we accept God exists it’s out of necessity, we don’t know if he actually exists
  • Because existence isn’t a property it cannot be a predicate of something
  • Therefore, the Ontological argument fails
• Challenge: Russel

  • Argues with Kant that existence is not a predicate
  • the word ‘exist’ is used incorrectly
  • If existence was a predicate it could apply to anything
  • Existence is a false predicate a word appears to describe something but it actually doesn’t
• Weakness: Gualino

  • We all have an idea of a perfect holiday
  • The holiday should be ‘the greatest holiday ever’
  • this means the perfect holiday exists in the mind
  • It is greater and more perfect in the mind than In reality
  • The perfect holiday does not truly exist.
• Weaknes: Gualino


  Rejects Anselm’s belief, just because you can think about it does not mean it will come true. There is always the idea of there being something greater rather than perfect.