The Ontological Argument

1. The Ontological Argument “For I seek not to understand that I may believe, but I believe that I may understand” - St. Anselm

2. There have been many varied reactions to the ontological argument. Charles Hartshorne: the ontological argument is “one of the greatest intellectual discoveries of all time.” Immanuel Kant: “The attempt to establish the existence of a supreme being by means of the famous ontological argument . . . is . . . merely so much labour and effort lost; we can no more extend our stock of [theoretical] insight by mere ideas, than a merchant can better his position by adding a few [imaginary dollars] to his cash account.” Whatever you think of the argument, all agree that Anselm’s argument may be treated as a reductio ad absurdum argument. That is, it begins with a supposition (S) that is contradictory to the proposition that one wants to prove. When one examines this supposition against one or more certain/self-evident assumptions (A1, A2, etc.), a contradiction is discovered which in turn demonstrates that the contradictory of S must be true.

3. S: Suppose that the greatest conceivable being (GCB) exists in the mind alone (and not in reality) • A1: Existence in reality is greater than existence in the mind alone. • A2: We can conceive of a being with all the attributes of the GCB that exists in reality as well as in the mind. • Therefore, there is a being that is greater than the GCB (from premises 1, 2, and 3). • But this is impossible, for it is a contradiction. • Therefore, it is false that a GCB exists in the mind alone and not in reality (from premises 1 and 5). • So, a GCB must exists in reality as well as in the mind. This being is, by definition, God.

4. Two common criticisms: 1) It is no more certain that the GCB exists than it is certain that the greatest conceivable island, bunny or basketball player exist. That is, there is nothing special about the idea of God that makes God exist; just as there is nothing special about the idea of an greatest conceivable island, bunny or basketball player exist. 2) It is a mistake to treat ‘existence’ as a ‘real predicate’. That is, when you think of an idea of something and add existence, you are simply saying that the idea itself is exemplified or instantiated. That is, there is nothing special about the idea of existence.

5. A second proof? (version 1) • 1. It is possible that God exists. • If God exists, God must be conceived as being the greatest possible being. • The greatest possible being must be a necessary being. • The existence of a necessary being must be either (a) impossible, (b) merely possible (contingent), or (c) necessary. • We can exclude (a), for it cannot be impossible for a necessary being to exist. There is no contradiction in the concept of a necessary being. • Nor can it be (b), that it is a mere possibility that God exists, for such existence would be (i) dependent and (ii) happenstance, and such a being could not be God. • Therefore, a necessary being necessarily exists. That is, God exists.

6. Anselm’s Second Proof? (version 2) • The existence of a necessary being can only be: (a) impossible, (b) merely possible (contingent), or (c) necessary. • The existence of a necessary being cannot be impossible; to say so is to admit a contradiction. • The existence of a necessary being cannot be merely possible (contingent), for such a being would be (i) dependent upon another for its existence and (ii) just happenstance. But a necessary being cannot be dependent or come into existence by happenstance. • Therefore, the existence of a necessary being is necessary. • A necessary being must exist, since it is impossible for a necessary being not to exist. • Necessary existence is a perfection. • The Greatest Conceivable Being has every perfection. • Therefore, the Greatest Conceivable Bring must be a necessary being. • Therefore, the Greatest Conceivable Being must exist. • The Greatest Conceivable Being is, by definition, God. • Therefore, God exists.