Philosophy Club

The Ontological Argument for the Existence of God

Introduction

The argument

1. Suppose G, the being than which no greater can be conceived, does not exist.
2. Then it is possible to conceive a being G* which is like G in all respects except in that G* exists whereas G does not.
3. Since G and G* are alike in all respects except in that G* exists and G does not, G* is greater than G.
4. So G* is greater than the greatest, which is impossible.

Some objections to the argument

1. The monk Gaunilon objected to Anselm's argument as follows: imagine that somewhere in the ocean there is an island which has all manner of riches in abundance. It is an island “than which no greater can be conceived”. By reasoning similar to that used by Anselm it can be shown that this perfect island must exist. Indeed, to extend Gaunilon's argument, if Anselm is right then there will be ontological proofs for all sorts of things - perfect islands, horses, tables, icecreams and so on.
   
   Anselm has replied to this objection. God is different from, say, a perfect island because God's existence is necessary by which Anselm means that God's non-existence is inconceivable. Thus God is truly the greatest conceivable being, unlike the perfect island which even if it existed would not be such that its non-existence were inconceivable.
   
   
   
   
2. The 18th century German philosopher Immanuel Kant presented an objection which can be summarised by the dictum “Being (ie existence) is not a real predicate”. In order to explain this objection consider briefly Descartes's version of the ontological argument. When discussing the notion of God, Descartes says:
   
   

   “...it is necessary that I should attribute to Him every sort of perfection, although I do not get so far as to enumerate them all...And this necessity suffices to make me conclude (after having recognised that existence is a perfection) that this first and sovereign being really exists.”

   
   
   
   Descartes makes explicit something which is presupposed by Anselm, namely that existence is one of a number of attributes (“perfections”) belonging to God. This is behind Anselm's talk of the painter who has in his understanding that which is going to paint. He says “For, it is one thing for an object to be in the understanding, and another to understand that the object exists.” In other words, the notion of existence adds something to the conception alone. In this way Anselm assumes that existence is an attribute (“perfection” or “predicate”). He then makes use of the idea that existence is one aspect of God's greatness - in other words, existence is one of God's attributes. Kant's objection is this: To say, for example, “Horses exist” adds nothing to the concept of a horse. “Otherwise, it would not be exactly the same thing that exists, but something more than we had thought in the concept; and we could not, therefore, say that the exact object of my concept exists.” Thus, the concept of a horse could never be instantiated. If Kant is right then the ontological argument fails to show anything because it is based on the idea that existence is indeed one of God's attributes. According to Kant, existence cannot be one of God's attributes (or an attribute of anything at all) because existence is not a real attribute at all.
   
   To extend Kant's objection, if existence were a real predicate, then a consequence of this would be that all true existential statements would be tautologies. To illustrate, consider the (true) statement “Tigers growl”. This can be analysed as “There are tigers and they growl”. In other words, it asserts that there are tigers and they have the property or attribute of growling. Now compare the statement “Tigers exist”. If this statement were like the previous one about growling then it too should be analysable as “There are tigers and they exist”. But this turns the true statement “Tigers exist” into a tautology. The sense of the original has been lost. This accords with Kant's argument that existence adds nothing to - is not an attribute of - an object. Existential statements such as “Tigers exist” have the form of subject/predicate statements, but this disguises the fact that assertions of existence are, logically speaking, quite different. Existence is not a real predicate or attribute.
   
   
   
   
   
3. A third criticism centres on whether or not there can be such a thing as an ontological proof. How can we establish the actual existence of anything from a mere definition (“that than which no greater can be conceived”)? Even if it is admitted that we have the concept of a being than which no greater can be conceived, how from that fact alone can it be established that such a being actually exists? There are concepts and there are things which exist, but we can't proceed by purely logical steps from one to the other.

Some questions

1. The American philosopher Norman Malcom has responded to Kant's criticism on behalf of Anselm. Malcom suggests that even if Kant is right about existence not being a real attribute, it may be the case that necessary existence is a real attribute. And since it is part of Anselm's argument that God's existence is necessary, this fact may provide a way out for Anselm. Do you think that Malcom's defence of Anselm succeeds?
   
   
2. We can prove by purely logical reasoning that certain things do not exist. For instance, it can be proved that square circles and largest primes do not exist. And perhaps it can be proved that there couldn't have been a particular moment in time when time first came into existence. It makes no sense to say that the Big Bang, by which space and time came into existence, occurred at 3pm. So if it is possible to prove by purely logical means that certain things do not exist, then similarly why can't it be proved by purely logical means that certain things do exist? Why can't there be an ontological proof for the existence of God?

References

1. St. Anselm, The Proslogium, in J. Hick (ed) The Existence of God.
2. R. Descartes, The Fifth Meditation, in Hick, op.cit.
3. I. Kant, excerpt from The Critique of Pure reason, in Hick, op.cit.
4. N. Malcom, “Anselm's Ontological Arguments” in Hick, op. cit.

R. Neurath