ontological arguments

the ontological arguments, their strengths and the critiques that face them

  • Created by: Jess2814
  • Created on: 01-02-23 19:56

Anselm's ontological argument

P1- god is a being greater than which can be conceived

P2- I can coherently conceive this

P3- it is greater to exist in reality than to only exist in the mind

C- therefore,  god must exist

strengths - 

1. god necessarily exists

2. people who have a concept of god but don't belive in him, believe in a contradiction

(apriori analytic argument)

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Descartes' ontological argument

P1- i have an idea of god

P2- this idea is of a supremely perfect being

P3- it is greater to exist in reality than to only exist in the mind

P4- existence is a perfection

C- therefore, god exists

strengths -

1. god exists apriori synthetically, which overcomes Hume's fork

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Malcolm's ontological argument (response to Kant)

one of the following must be true:

1. god's existence is necessarily false

2. god's existence is contingently false

3. god's existence is contingently true

4. god's existence is necessarily true

Malcolm rules out options 2 and 3 - this would mean that god would go in and out of time, meaning he would have to rely on something to exist

Malcolm rules out option 1 - 'god exists' is not a contradiction

leaves Malcolm with option 4 - 'necessary existence' is the predicate that overcomes Kant as 'necessary' adds to the subject (god)

strengths - strongest argument 

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Gaunilo's critique

the perfect island

P1- we can imagine an island that is the greatest that can be conceived

P2- it is greater to exist in reality than merely in understanding

C1- therefore, the island must exist

P3- obviously C1 is untrue

C2- therefore, Anselm's argument is invalid

AO2 -

  • attacks logic (uses a reductio ad absurdum)
  • critiques Anselm and Descartes
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Anselm's response to Gaunilo

the ontological argument only works for god, so this is not a counter example:

'the greatest conceiveable being doesn't exist' = incoherent

     by contrast, god wouldn't be god if there was some being greater         than him, so being the greatest conceiveable being is an essential       property of god.

'the greatest conceiveable island doesn't exist' = coherent

     islands aren't essentially great or not. god has to exist, the           island does not.

success -

  • Gaunilo fails toundermine Anselm and Descartes
  • he misunderstood the ontological argument and misapplied his reductio ad absurdum, therefore providing a defence to A and D
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empiricist objections to apriori arguments for exi

P1- nothing that is directly conceivable implies a contradiction 

P2- whatever we conceive as existent, we can also conceive as non-existent

C- therefore, there is no being whose non-existence implies a contradiction


  • attacks structure (attacks the use of apriori knowledge)
  • critiques Anselm, Descartes and Malcolm
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Descartes' response to Hume

1. Descartes combines Hume's fork and rejects P2 of Hume's argument -       Descartes claims that 'god exists' is both an analytic truth (though     not an obvious one) and a synthetic truth

2. the ontological arguments only apply to god, so Hume's argument can     only apply to something or someone other than god - the existence of     god is necessary

success -

  • critique is unseccessful
  • the response makes Hume's fork false, which rejects P2 of Hume's argument, therefore successful in overcoming the critique
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Kant's critique

objection based on existence not being a predicate

P1- if 'god exists' is an analytic truth, then 'exists' is a part of god

P2- existence is not a predicate

C1- therefore, existence is not part of the concept of god

C2- therefore, 'god exists' isn't an analytic truth

C3- therefore, the ontological arguments cannot prove god's existence


  • attacks conclusion
  • critiques Anselm (P3 of his argument)and Descartes
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response to Malcolm's ontological argument

Malcolm can't rule out option 1:

  • he misunderstands what a contradiction is
  • if god doesn't exist, what makes god's existence impossible isn't the self-contradictory nature of the concept of god, but the self-contradiction in the idea of bringing into existence something that doesn't rely on anything to exist
  • Malcolm proved an 'if' statement - he proved that IF god were to exist, he'd exist necessarily, not that he necessarily exists


  • Malcolm fails to prove god's existence
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essay plan

final answer - the ontological arguments cannot prove god's                 existence, only the type of existence he has

P1- intro

P2- outline Anselm's argument and provide a strength

P3- Gaunilo's critique and how it fails

P4- outline Kant's argument and provide a strength

P5- outline Malcolm's argument and provide a strength

P6- response to Malcolm

P7- conclusion

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