Ontological Argument

• What type of argument is the ontological argument?


  A priori - an argument that is based on logical deduction and is priori to sense experience.
• What is a necessary truth?

  a proposition that could be false
• what is a necessary thing?

  something that could not have possibly failed to exist
• what is a contingent thing?

  something which does not exist necessarily and so could have failed to exist
• What is an analytic statement ?

  a statement which is true by definition
• what is a synthetic statement?


  a statement or proposition where true or false are determined by the sense of experience.
• what is a predicate?


  A quality/property of an object or subject.The predicate gives us information about the subject meaning it is ontological
• what does anselm believe?

  'i believe in order to understand'

  • i belief precedes understanding.His argument is written as a prayer ,Anselm is a committed theist whose argument is anchored in the theistic language game.
• what is the argument based on?


  The argument is based on the claim that God's existence can be deduced from his definition-once god is correctly defined there fam be no doubt that he exists
• What are the 3 claims of the ontological argument?

  • The proposition 'god exists' is a priori/deductive - it can be known to be true without reference to sense the experience just by thinking about Gods nature.
  • In the proposition 'god exists' the subject 'God' contains the predicate 'exists' so God must exist
  • Gods existence id a necessary truth not a contingent one
• What is the ontological argument?

  1. The fool says in his heart 'there is no God' -They have a concept of God because if they are talking about God they have a concept of.
  2. Anselm’s definition of God : 'God is a being that than which nothing greater can be conceived'
  3. Even a fool would accept this definition of God
• Ontological argument

  Argument for the existence of God
• God

  The greatest conceivable being that than which nothing greater can be conceived
• This is a definition even a fool understands in his mind even though he does not understand it to exist in reality
• Idea in the mind

  Having an idea in the mind
• Knowing an idea exists in reality

  Knowing that the idea exists in reality
• It is greater to exist in reality than to exist only in the mind
• If God only existed in the mind

  I could think of something greater, namely a God who exists also in reality
• What is Gaunilo's Criticis?

  He uses a parody of Anselms argument.

  He gave an ontological argument for the existence of a perfect island.He says to imagine an insiald which no greater island can be conceived but uses Anselms argument to illustrate the flaws

  1. It is possible to conceive the most perfect island
  2. It is greater in reality than to exist only in the mind
  3. Therefore the perfect island must exist in reality
• What is Gaunilos idea of 'reductio ad absurdom'

  He suggests that Anselms argument could be used to prove the existence of an endless number of perfect objects.

  The real fool is anybody who argued something into existence in this way

  We can show a posteriori that this perfect island does not exist,so Anselms priori argument does not work.
• What was Anselms response?

  Contingency vs Necessity
• Anselms respone was Contingency bs necessity meaning what?

  He writes ,'God cannot be conceived not to exist- God is that than which nothing greater can be conceived-That which can be conceived not to exist is not God’

  1. Islands are contingent
  2. God is necessary
  3. Anselm argues that you cannot compare God to an island.God is a special case
  4. You cant use the argument for anything but God
  5. This is because islands are contingent meaning they cannot exist necessarily
  6. Necessary existence is only a predicate of God and not of things
• Why does Decartes agree with Anselm?

  'I think therefore i am'

  • God is defined as the supremely perfect being.
  • He must therefore possess all the perfect predicates of omnipotence omniscience, omnibenevolance
  • He must also possess existence
• Ao2: Strengths of the ontological argument 


  -it has certainty as a deductive argument.If the premises are true, the conclusion must be true.

  • Whilst inductive arguments are only probabilistic deductive arguments give absolute certainty
  • Argument doesn’t really rely on empiricism (observation) which is criticised by Plato 'the body is a source of endless trouble for us'- we cannot trust our senses and our observations because they deceive us.Knowledge gained in this way is unreliable
  • Deductive arguments gibe absolute certainty
• A02: more strengths of the ontological argument


  • It is a deductive argument meaning that is it succeeds it is absolute proof of the existence of God
  • It is much more reliable a d certain than inductive arguments which can only give probability
  • Decartes