1. Introduction to Philosophy Lecture 5 The Ontological Argument By David Kelsey

2. Saint Anselm Saint Anselm of Canterbury lived from 1033-1109. He was a monk and later Archbishop of Canterbury. Wanted to see how far argument and reason could substantiate the central doctrines of Christianity. He invented the ontological argument for the existence of God.

3. A priori vs. A posteriori arguments A Posteriori Arguments: –An a posteriori argument has at least one premise which is contingent. It has at least one premise that is a question of fact. –Examples: the Cosmological and Teleological arguments for the existence of God A priori arguments: –Have absolutely no premises that are a question of fact. –Composed entirely of a priori claims. –An a priori claim: true or false in virtue of the meaning of it’s words alone. The ontological argument is an a priori argument…

4. Defining GOD According to the Judeao-Christian-Islamic tradition: God is the greatest or most perfect possible being. –What can we infer about God from this? –If God is perfect, he has every perfection. Thus, God is: –Omnipotent: maximally powerful –Omniscient: maximally knowledgeable –Omnibenevolent: is perfectly good –Omnipresent: is everywhere What other perfections might there be?

5. A Reductio for God’s omnipotence An argument that God must be omnipotent: –Suppose God wasn’t omnipotent. –Then there could be a being more powerful than God. –That would be greater than God. –But God is the greatest of all possible beings. –So God must be omnipotent. This argument has the form of a reductio ad absurdum. –Reductio’s always assume the negation of the conclusion they are out to prove. –The argument then derives a contradiction A contradiction: –Asserts that something both is and isn’t the case –cannot possibly be true –The contradiction above: –The argument then concludes by asserting what it was to prove

6. The form of the Reductio So here is the form of our reductio: –1. God isn’t omnipotent. –2. Thus, there could be someone more powerful than God. –3. Thus, there could be someone greater than God. –4. But, by definition, God is the greatest possible being; there couldn’t be someone greater than God. –5. Thus, there both can and can’t be someone greater than God. –6. Thus, (1) is false: God is omnipotent.

7. Anselm’s Ontological Argument Anselm’s concept of God: –Anselm uses the notion of God seen in the Judeao-Christian-Islamic tradition. –For Anselm: God is ‘something than which nothing greater can be conceived’. This is not the same concept as the greatest being we can conceive. Such a concept would be limited by the way us humans conceive of things…. –Anselm is assuming the Great chain of being here. If you run up and down the chain you find it easy to conceive of beings both lesser and greater. Your mind is carried to greater and greater things…

8. The Great Chain of Being The Great Chain of Being: –God created the world ex nihilo, out of nothing. The world is entirely dependent upon God. –Reality is partitioned in graded steps, which are infinitely close to each other. Being and nothingness are mixed in all degrees in all things. God has the most being, then the angels, then rational creatures, then more primitive life forms such as dogs, insects, etc., then to inanimate matter, I.e. rocks… –Consider a cat… –There is a direct correlation between being and goodness. The more being something has, the more good it has. So God who has the most being, is completely good. The created world is less good than God, but still good.

9. Anselm’s Reductio Anselm’s argument is a Reductio Ad Absurdum. The basic form of the reductio: –Assume God doesn’t exist –But then God isn’t the being than which nothing greater can be conceived. –But God is the being than which nothing greater can be conceived. –Thus, God exists.

10. The form of Anselm’s argument Anselm’s argument: –1. Assume God exists in the understanding alone. –2. God is something than which nothing greater can be conceived. –3. Something than which nothing greater can be conceived exists in the understanding alone. (from 1 and 2) –4. Something than which nothing greater can be conceived can be conceived to exist in reality. –5. It is greater to exist in reality than in the understanding alone. –6. Something than which nothing greater can be conceived is a being than which a greater can be conceived. (from 3 and 5) –7. God both is and isn’t something than which nothing greater can be conceived. (from 2 and 6) –Thus, 8. God exists. (from 1 and 7)

11. Evaluating Anselm’s argument Evaluating Anselm’s argument: –Is Anselm’s argument valid? –Is Anselm’s argument sound? –Which premises might be false? Premise 1… Premise 2… Premise 4… Premise 5…

12. Denying premise 2 Denying premise 2: –Some argue that premise 2 is false. –They say that such a definition of God is incorrect. –Thoughts…

13. Denying premise 4 Challenging the fourth premise: –Can you conceive of God as existing in reality?

14. Denying premise 5 Can we deny premise 5: –We can do this by claiming that existence in reality is not a perfection. –Thus, a being that existed in both the understanding and in reality is not more prefect than a being that existed just in the understanding. Anselm’s reply would probably go like this: existence entails the ability to use all of one’s perfections Counter: Is existence the kind of thing that can even be a perfection at all?

15. Defining God into existence Hume criticizes the Ontological argument for trying to define God into existence. –Remember that the ontological argument assumes: You cannot think of God without thinking God exists –For Hume though, it may be that thinking of God entails thinking that he exists but this concerns only relations of ideas not matters of fact. A relation of idea is: –Discoverable by the mere operations of thought, without dependence on anything existent in the universe… A matter of fact is: –Discoverable by observation of the external world… –So even though thinking God entails thinking he exists, this has nothing to do with whether God in fact exists. So pointing out that the thought of God includes in it the thought of existence doesn’t entail the truth of the matter of fact that God exists. A relation among ideas, even one that is necessary, gets no traction and can have no causal power on how things are in the world. Relations of ideas cannot prove matters of fact. About matters of fact, we must consult experience.

16. Refutation by logical analogy Refutation by Logical Analogy: –Many people think that Anselm’s argument just has to be wrong for it just shows too much. –Can’t we give an argument of the same form as Anselm’s, but for an obviously false conclusion. Since the new argument isn’t sound, neither is Anselm’s. This move is called Refutation by logical analogy.

17. Gaunilo’s parody Here is the argument: –1. The greatest possible island exists in the understanding alone. –2. The greatest possible island is the island than which no greater can be conceived. –3. The island than which no greater can be conceived exists in the understanding alone. (from 1 and 2) –4. The island than which no greater can be conceived can be conceived to exist in reality. –5. It is greater to exist in reality than in the understanding alone. –6. The island than which no greater can be conceived is an island than which a greater can be conceived. (from 3 and 5) –7. The greatest possible island both is and isn’t the island than which no greater can be conceived. (from 2 and 6) –Thus, 8. The greatest possible island exists. (from 1 and 7)

18. Anselm’s reply Anselm’s possible replies to Gaunilo: –He could give up or bite the bullet. –Gaunilo’s argument isn’t valid… –A premise from Gaunilo’s argument is false…

19. Anselm’s best reply Anselm’s reply: –Can the greatest possible island even exist in reality? –Although the greatest possible being could have all the perfections to the greatest degree, could an island really have them?