Anselm's ontological argument

• anselms argument is a priori

  • this type of argument is independent of sense experience
  • it is non-empirical
  • it relies on logic
• anselms argument is deductive

  • aims to give certain proof
  • if the premises are true, then the conclusion must be true
  • a set of premises is a set of propositions on which an argument is based or from which a conclusion might be drawn
• analytic statements

  • they are based on logic
  • they are true by definition- for example, a bachelor is an unmarried male
• subject and predicate

  • the subject refers to who/what the sentence is about
  • the predicate gives information about the subject
• necessary truths


  relate to statements that could not possibly be false- for example, a circle has no sides
• necessary things


  things that cannot possibly fail to exist- for example, the laws of mathematics, according to some mathematicians and scientists
• the ontological argument is based on Anselm's definition of god, and god existence can be deduced from that definition.

  the proposition 'god exists' is a priori and deductive. it contains the predicate 'exists' in relation to the subject 'god' so god must exist. it is a necessary truth.
• proslogium 2

  • god is 'that which nothing greater can be conceived'
  • quoting from psalm 14:1, Anselm showed even the fool understood the concept of god.
  • there is a difference between having a concept in the mind and knowing it exists in reality
  • if god exists only in the mind, a greater being could be conceived- one that lived in reality.
  • so god cannot exist only in the mind, he must exist in both mind and reality.
• challenge to Anselm: gaunilo: 'on behalf of the fool'

  • followed the same structure as anselms' substituting god for the lost island
  • the lost island is that than which nothing greater can be conceived
  • it is greater to exist in reality than only in the mind
  • if it exists only in the mind, then a greater island can be conceived
  • so the lost island exists in both the mind and reality
• proslogium 3 and the responsio

  • pointed to the distinction between necessity and contingency- it is greater to be a necessary being than a contingent one
  • if god is only contingent, then a greater being could be imagined
  • that being would be greater than god, which is ridiculous given the definition
  • therefore god is a necessary being
  • Anselm pointed to the difference between an island and god: islands and contingent, god is not.
• what is a necessary being?

  a being whose non-existence would be contradictory
• what is a contingent being?


  something that may or may not exist, being dependent on something else for its existence.
• what do Kant's two challenges to the ontological argument stem from?


  his conviction that statements about existence

  • are synthetic, not analytic
  • must be proved through sense experience
• synthetic statements


  statements that could be true or false. their truth or falsity is determined by sense experience.
• kants criticisms of the ontological argument: existence is not a predicate

  • a real predicate is something that gives information about a subject (e.g. 'the cat sat on the mat', 'sat on the mat' gives information about the cat)
  • going on to say the cat exists gives no further information about the cat
  • kant used the example of thalers. it is possible to describe the appearance and feel of thalers. but to say they exists says nothing more about them. there is no difference between a concept of 100 thalers and 100 whalers that actually exist.
• kants criticisms of the ontological argument: something cannot be defined into existence

  • Kant accepted that necessary existence belongs to the concept of god
  • but this does not mean that god actually exists
  • the fact that something could exist does not mean it actually does exist.
• strengths of anselms ontological argument

  • it is a deductive argument, so if it works, it gives absolute proof as opposed to other arguments' reliance on probability (inductive)
  • its independence of evidence from human observation protects it from possibly unreliable evidence
  • anselms definition is in fact claiming that god is limitless and for many, if there is a god, his definition makes good sense.
• weaknesses of anselms ontological argument

  • kants challenges suggest that it does not work in either of its forms
  • arguments about existence need to be empirically based
  • aquinas and others since have challenged anselms definition of god. humans cannot know the nature of god and any attempt to define god limits him. if this is the case the whole of the ontological argument collapses.
• 'anselms argument does prove the existence of god'

  • the nature of the argument as a priori, analytic and deductive means that if its premises are true, them it does indeed prove the existence of god. many scholars have claimed, and still do claim, that is it valid
  • some claim it is a proof- a faith-based acceptance
  • Barth claimed Anselm never intended it as a proof. he thought it consisted of anselms meditation on a religious experience
  • some theologians think it was simply a meditation on the nature of god that it was intended to assure his fellow monks that their faith was reasonable.
• the value of anselms argument for religious faith: the positive side

  • the argument works for those who are already theists
  • it shows that their religious belief is rational
  • the reasoned 'belief that' god exists reinforces and supports 'belief in' (commitment to) god.
• the value of anselms argument for religious faith: the negative side

  • if it fails as a proof, its value to religious faith is limited
  • fideists reject the use of rational arguments to prove the existence of god. they think that reliance on such arguments devalues faith.
  • Barth rejected attempts to prove gods existence through reason. he said god can only be known through revelation, not logic. he claimed Anselm never intended proslogium to be seen as an argument proving gods existence through logic and that he was simply trying to understand the god he believed in after a religious experience