Ontological argument

Question 1

Explain Anselm’s ontological argument

Answer 1

P1: God is defined as the greatest possible being (‘that than which nothing greater can be conceived’).

P2: Even an atheist (‘the fool’) can conceive of God as the greatest possible being, as it is a coherent concept that exists in our understanding.

P3: It is greater to exist in understanding and in reality than existing in understanding alone.

C: Therefore the greatest possible being, God, must exist in understanding and reality.

Question 2

Explain Gaunilo’s perfect island objection

Answer 2

Gaunilo questions Anselm’s claim that we can prove the existence of God simply on the basis of a concept that exists in our understanding through this argument:

P1: There is a lost island which is the most excellent of all islands (Gaunilo describes it as having ‘all manner of riches and delicacies in great abundance’).
P2: No one has difficulty conceiving of this lost island as the most excellent island - it exists in our understanding.
P3: It is more excellent to exist in understanding and in reality than in understanding alone
C: Therefore, the lost island must exist.

This argument presents an issue for Anselm’s ontological argument as it shows the absurdity of his reasoning.

Question 3

Explain Descartes’ ontological argument

Answer 3

Descartes’ ontological argument is an a priori (independent of experience) and deductive (where the truth of the conclusion is guaranteed by the truth of the premises) argument which seeks to prove the existence of God.

P1: I have the idea of God as a supremely perfect being
P2: A supremely perfect being must have all perfections
P3: Existence is a predicate of perfection
C: Therefore, God exists

Question 4

Explain Malcolm’s ontological argument

Answer 4

P1: Either God exists or God does not exist
P2: If God does not exist today, then his existence is logically impossible (as nothing can cause God to exist)
C1: Therefore, if God does exist, his existence is necessary
P3: God’s existence is either impossible or necessary
P4: God’s existence is not impossible
C2: Therefore, God’s existence must be necessary

Question 5

Explain empiricist objections to a priori arguments for existence

Answer 5

The ontological argument aims to establish the existence of God a priori (independently of experience) . However, empiricist philosophers (who believe that knowledge stems from experience), such as Hume and Ayer, object to this.

Hume’s objection is as such:
P1: Nothing that can be distinctly perceived entails a contradiction.
P2: For any being we can conceive of as existent, we can also distinctly conceive of that being as non-existent
C: Therefore, there isn’t being whose non-existence implies a contradiction, meaning that the ontological argument fails to prove God’s existence a priori.

Ayer’s objection is as such:
P1: A priori propositions are only certain because they are tautologies.
P3: The existence of anything, including God, is not a tautology.
C: Therefore we cannot validly deduce the existence of God from a priori propositions, and the ontological argument fails.

Question 6

Explain Kant’s objection to the ontological argument based on existence not being a predicate

Answer 6

P1: A genuine predicate adds to our conception of a subject and helps us to determine it (e.g. he gives the example of Thaler coins - a predicate of this would be gold or shiny)

P2: ‘Existence’ does not add to our conception of a subject or help to determine it (saying that the Thaler coins exist does not add any information to our conception of them)

C: Therefore existence is not a genuine predicate

This presents an issue for Descartes’ ontological argument, which proceeds on the basis that existence is a predicate of God. If existence is not a predicate, as Kant argues, then Descartes’ ontological argument contains a false premise.