Ontological argument

Anselm’s ontological argument?

1. God is that which nothing greater can be conceived

2. God exists in our minds

3. that which exists in reality is greater than that which exists in the mind

C. God exists

Philosophers later made the distinction between something having an intentional existence and a formal existence. The atheist and theist both have a notion of God’s intentional existence but the former denies the formal existence.

Gaunilo’s critiques of Anselm’s argument

• Gaunilo’s parody island - use’s Anslem’s deductive reasoning to produce an absurd conclusion of a “lost island”, whose beauty surpasses any place. He is trying to say that one can imagine a perfect anything and then argue that because it is the most perfect thing imaginable then it must exist

  • Anslem responds by making an emphasis on the contingent existence of an island, versus the necessary existence of God. The greatest possible island will always be dependent on something else to exist, but there is nothing in Anselm’s definition that implies God’s existence is contingent too. This is very persuasive, because God is not like an island.

How does Aquinas criticise the ontological argument?

• not everyone agrees on how God should be defined. The argument can only work is there is some unanimity about how God should be defined

• even if everyone agreed on the definition, Aquinas thinks that it only follows that we must think of God as existing, not that God actually does exist

Descartes’ ontological argument

1. God is a being who possesses all perfections

2. Existence is a perfection

3. God possesses existence

C. God must exist

Descartes is arguing that God’s existence is a logical necessity. God as existing is an analytic truth - existence is a necessary part of the definition of God. For Descartes, it is like saying “the God who exists, exists”. It would be like questioning whether a triangle possesses three interior angles that sum to 180 degrees.

He makes a comparison between the truths of mathematics and the truth of God’s existence. We cannot imagine triangles without three angles in the same way we cannot imagine God without existence.

Kant’s critiques of the ontological argument

1. existence is not a predicate. Existence does not tell us anything about an object. One would describe a set of 100 real coins and 100 imaginary coins with exactly the same adjectives - but we would not use the word “exist”. Existence is precondition of an object having any predicates.

2. It is impossible to make an “analytic existential proposition”. (The argument is a priori, analytic because it is not based on any empirical observation. Descartes compares God’s existence to analytic truths like all bachelors are unmarried men, or all triangles interior angles sum to 180 - these statements are necessarily true. But, for Kant, the same cannot be said of God;s existence, because we could imagine a non-existent God in a way that we could not imagine a bachelor who is married.

How does Hume critique the ontological argument?

• he claimed that nothing can ever be proven to exist through an a priori, rational argument. The only way to prove something a priori is if its opposite implies a logical contradiction - if it implies a contradiction, then it is inconceivable. But we can conceive of God to not exist - this is not a contradiction.

• a priori truth tells us almost nothing about the real world. E.g. to make the assertion “all bachelors are unmarried men” does not tell us whether a bachelor exists in reality, only that the definition of a bachelor is thus

Evaluative conclusion

• Karl Barth makes the point that Anslem’s argument is a meditation on the greatness of God, and should be seen as an expression of faith rather than trying to convince us to believe. To imagine the non-existence of God is to imagine the non-existence of existence itself.

• but Anselm does set out some kind of proof. Perhaps it is most convincing as a commitment to faith for those who already do believe.