Anselm's Ontological Argument and Its Critics

Introduction to Philosophy

Instructor:  James Ransom

December 17, 2012

Anselm:  The Ontological Argument for God’s Existence

St. Anselm, the Catholic archbishop of Canterbury and a Doctor of the Church, first formulated the Ontological Argument in 1078 A.D., in his work the Proslogion. The proof is most notable because it alone claims to prove the existence of God by relying independently on human reason without the need for perception or evidence. The proof itself relies on the defined concept of God as a perfect being. St. Anselm’s proof is summarized here:

1.     God exists in our understanding. This means that the concept of God resides as an idea in our minds.

2.     God is a possible being, and might exist in reality.

3.     If something exists exclusively in our understanding and might have existed in reality then it might have been greater. Something that is only a concept in our minds could be greater by actually existing.

4.     Suppose (theoretically) that God only exists in our understanding and not in reality.

5.     If this were true, then it would be possible for God to be greater then he is (follows from premise #3).

6.     This would mean that God is a being in which a greater is possible.

7.     (6) is absurd because God is by definition a being in which none greater is possible. Herein lies the contradiction.

8.     Thus it follows that it is false for God to only exist in our understanding.

9.     Hence God exists in reality as well as our understanding.

ASSIGNMENT FOR TUESDAY, DECEMBER 17

BENEDICT:  Present 5-minute oral argument  ADVOCATING Anselm’s Ontological Argument (“AOG”)

BRENDAN:  Present 5-minute oral argument REBUTTING              AOG

LOUIS:        Expose deficiencies in Brendan’s rebuttal  and present a CONCLUDING ARGUMENT   for AOG

LUCIAN:      Rehabilitate Brendan’s critique and present a CONCLUDING ARGUMENT against AOG

CRITIQUES AND DEFENSES OF AOG

CRITICS OF AOG	CRITIQUE
Gaunilo of Marmoutiers (1)	Think of a perfect island.  According to Anselm’s proof, this island must exist, because a perfect island in reality is superior to a perfect island only in thought.  Reductio ad absurdum argument
Gaunilo of Marmoutiers (2)	God cannot be fully conceived because his nature is inexhaustible.  Therefore, if humans cannot fully conceive of God, AOG cannot work
St. Thomas Aquinas	Echoed Gaunilo (2).  ST 1aQ2
David Hume	Whatever we can conceive as existent, we can also conceive as non-existent. Dialogues Concerning Natural Religion (1776)
Immanuel Kant	Necessary propositions regarding a being are only necessarily true if the being exists; for example, a triangle must have 3 angles only if the triangle exists. Critique of Pure Reason (1787)
Bertrand Russell	“The argument does not, to a modern mind, seem very convincing, but it is easier to feel convinced that it must be fallacious than it is to find out precisely where the fallacy lies."  History of Western Philosophy  (1972)
Richard Dawkins	"The very idea that such grand conclusions should follow from such logomachist trickery offends me aesthetically…[I feel a] "deep suspicion of any line of reasoning that reached such a significant conclusion without feeding in a single piece of data from the real world."  The God Delusion
DEFENDERS OF AOG	DEFENSE
Rene Descartes	The concept of God is that of a supremely perfect being, holding all perfections. Existence is a perfection: it would be more perfect to exist than not to exist. Thus, if the notion of God did not include existence, it would not be supremely perfect, as it would be lacking a perfection. Consequently, the notion of a supremely perfect God who does not exist,  is unintelligible. Therefore, according to his nature, God must exist. Fifth Meditation (1641)
Mulla Sadra	God by definition is perfection in existence. Existence is reality.  Reality is graded on a scale of perfection.  That scale must have a limit, a point of greatest intensity of existence.  That point is God.  Hence God exists.  Argument of the Righteous (c. 1610)
Kurt Gödel	X is God-like if and only if X has as essential properties those and only those properties which are positive (i.e., not privative).  If a property is positive, its negation is not positive.  The property of being God-like is positive.  Necessary existence is positive. If a property is positive, then it is consistent [with actual existence].  The property of being God-like is consistent. Therefore, existence is an essence of that thing.  Therefore, God exists. Posthumous Papers  (probably composed c. 1941)