1. Ontological Argument for God Introduction to Philosophy Jason M. Chang

2. Lecture Outline 1. Background 2. Major ideas 3. The argument 4. Objections A. Gaunilo’s objection B. Perfect objection C. Kant’s objection

3. Background o Definition of “ontology” o A priori vs. a posteriori o St. Anselm of Canterbury St. Anselm 1033-1109 AD

4. Major ideas Major ideas in the ontological argument Necessary vs. contingent attributes o Definition Attributes of a Perfect Being (the greatest possible being)

5. Major ideas Major ideas in the ontological argument Existence in reality vs. existence only in the understanding Anselm on existence o The claim o Reasoning

6. The argument (P1) God is the greatest possible being. (P2) Existence in reality is greater than existing only in the understanding. Therefore, (C) God must exist (given that He is the greatest possible being) Note: This is a simplified version of Anselm’s argument. In the original version, Anselm shows that believing that the greatest possible being exists only in the understanding leads to a contradiction. (reductio)

7. Common objections

8. Gaunilo’s objection Strategy o Refute (P2) Perfect island Gaunilo of Marmoutiers

9. Gaunilo’s objection “Suppose that a person tried to prove to me by this reasoning that this island actually exists […] [If I believed him], I would not know which I ought to regard as the greater fool: perhaps myself for supposing that I should allow this proof, perhaps him for supposing that he had established with any certainty the existence of this island”

10. Perfect murder objection Greatest demon objection Strategy o Denies that “existence” makes a thing greater Q  Is something really greater if it exists in the world than if it exists only in the mind?

11. Perfect murder objection Things in which “existence” adds to their goodness Things in which “existence” detracts from their goodness

12. Kant’s objection Strategy o Deny that “existence” is an attribute Immanuel Kant (1724-1804)

13. Kant’s objection Attributes are characteristics or properties ascribed to something -Intelligent -Witty -Thin -Fit Many of these attributes can add to the value of something Kant  EXISTENCE is not an attribute