In the the second chapter of the Proslogion (Discourse, 1077), St Anselm, a well-regarded philosopher and theologian, presented the original statement of what in the eighteenth century became known as the ontological argument for the existence of God. However, Anselm himself never referred to it by that title and, it might be suggested, was not really attempting to present a coherent argument in the first place.
Unlike the other arguments we have looked at – so called a posteriori arguments – this one is a priori. A posteriori knowledge is the most common form of knowledge we possess. As an example, my knowledge that Hitler was appointed Chancellor in 1933, or my knowledge that sunflowers have yellow petals. This form of knowledge can be verified (or, indeed, falsified) by experience (that is, through observation, looking up the information in a reliable reference book, past experience, etc.). However, it may be argued that not all of our knowledge comes from experience alone. For example, the fact that 2+2=4. Such mathematical formulations seem to be objective, universal facts and, some would argue, can be determined prior to experience.
`And so, O Lord, since thou givest understanding to faith, give me to understand – as far as thou knowest it to be good for me – that thou dost exist, as we believe, and that thou art what we believe thee to be. Now we believe that thou are a being than which none greater can be conceived.’
(From Proslogion, Chapter 2)
The important part of this quote is what Anselm meant by “that thou are a being than which none greater can be conceived”. Two key words here need to be clearly defined. First of all, what did he mean by “conceived” (some translations use the word “thought”? Judging from the Proslogion, the primary meaning of this word is synonymous with that which is logically possible. However, the problem here is that it certainly seems possible to conceive of God’s non-existence. As we will examine later, however, the conception of the non-existence of God is, in fact, logically impossible!
The second key word is what he meant by “greater”. Although Anselm himself does not define what he meant by this, it seems apparent that he is not merely limiting himself to “goodness”, but is using it in the more all-encompassing manner that suggests God’s omnipotence; i.e. powerful, able, and so on. It is obvious that he did not mean the greatest being that you or I can possibly think of, or conceive, simply because we are limited in our conceptions. What Anselm meant was the greatest being that it is logically possible for any conceiver to conceive of. The very fact that Anselm meditates upon the property of God as being `the greatest being’ means that God must be greater than the human conception of “greatness”.
Having at least some idea of what Anselm meant by his terms, lets look at the main points of the argument:
1. There are two types of existence.
We can conceive of things that exist in reality, but we can also conceive of things that do not. This does not in itself prove they exist, and therefore, we are not really comparing like with like. It’s rather like playing chess; you may be about to checkmate me but I say that I have imagined, or conceived, that I have three queens that have surrounded your king and, therefore, I win!
2. That which exists in the mind could possibly exist in reality.
It could be argued that Superman might, in fact, exist; if not exactly how we conceive of him. After all, a man that flies through the skies in leotards is not a logical impossibility (unlike a square circle). The fact that we are able to conceive of a being that is capable of performing acts that we, as mere mortals, are not, at least points to its possibility, even if you are unable to understand all of its attributes.
3. Things that exist in reality are greater than those that exist in the mind.
This is a vital point in the argument. Remembering our definition of “greater” as omnipotence, Anselm suggests that if you can conceive of something greater in the mind and that there is a possibility that it exists, then its existence would be greater (in terms of more powerful, able, freer, and so on) than a figment of someone’s imagination. My imaginative chess pieces may be powerful in my mind, but not much help unless they exist on the chess board.
4. God only exists in the mind!
Anselm obviously didn’t believe this, but what he is doing is making use of the reductio ad absurdum argument to show that if you assume that God does not exist in reality you are making a logical error. Why? If we accept the definition that God is “a being than which none greater can be conceived”, and we also accept the argument that a being that exists in reality is considerably greater (more powerful) than one that exists in the mind, then God must exist! God in reality is far greater than God in the mind. Therefore:
5. God exists both in reality and in the mind.
Provided we accept the possibility of “the greatest being”, and that which exists in reality is greater than that which exists in the mind, then God, as the greatest being, cannot exist only in the mind.
It is worth looking at two objections that the monk Gaunilo raises in response to Proslogion:
(i) An idea in the mind does not require its existence.
I can imagine all sorts of things: Santa Claus, unicorns, etc. Having the notion of a thing is, however, not the same as the thing itself. Yet this is what Anselm seems to believe; that the idea of a thing is a lesser version of the thing in reality. Anselm is inheriting a metaphysics of truth that owes some debt to St. Augustine; that is, God is the Supreme Truth. Conceiving of God is, by definition and logically speaking, conceiving of that which is true and Anselm is making an association between truth and reality. For example, the definition of Santa Claus is not “the Supreme Truth” nor, for that matter, is he “the greatest being”; he is a jolly fat man who comes down chimneys with presents. To have a notion of Santa Claus you do not have to accept that he exists in reality because his definition doesn’t require it.
(ii) By Anselm’s logic we can prove the existence of anything.
This is Gaunilo’s most famous retort. He used the example of an island:
We can conceive of a perfect island
A perfect island must be more perfect in reality than in the mind
Therefore, a perfect island exists.
Gaunilo was following the same logical structure as Anselm to show that all manner of things can exist. Anselm replied to this in his short work, Reply to Gaunilo. His response depends on understanding two important concepts:
(a) Logically necessary existence
Anselm would simply say that “God is different from an island”. But in what way? God is the greatest of all things; all-powerful. Such a being, again by definition, cannot be reliant upon any other being. As Leibniz said, “There must exist some one Being of metaphysical necessity, that is, to whose essence existence belongs.” This is the classical definition of God; not created by anything else and therefore not dependent upon anything else; yet a necessary being for other beings to exist.
(b) Contingent existence
An island, however, is not, by definition, the greatest of all beings. It is contingent in the sense that is dependent for its existence on – if nothing else – God. Therefore, we may attempt to conceive of the greatest, or most perfect, island but we are still then able to conceive of something even greater than that! Seemingly, the only way you can get out of this argument is by defining an island as omnipotent! Here, again, Anselm is showing that his definition of “greatness” is synonymous with omnipotent; not with “most beautiful mountains” or “tallest” etc.
Kant argued that using the term “exists” as if it has some real value is a mistake: the word “exists” is not a “real predicate”. For example, the sentence “that car is fast” has two elements: the subject (`car’) and a predicate (`fast’). The purpose of the predicate in this case is to provide some extra _ and useful _ information about the car and is, therefore, a real predicate. You could say “that car is flimflar” in which `flimflar’ is a logical predicate, but not a real one because it tells you absolutely nothing about the car itself.
So, for Anselm to talk about God in terms of “existence” is telling us nothing whatsoever about God. Anselm was, after all, attempting to show that, through a priori reasoning, we can learn something about the nature of God.
At first, Kant does appear to have a strong argument; in cases where it is already pre-supposed that something exists. For example, describing my car to you will tell you much about my car (“dirty, old, rusting, noisy”), but to then add “it exists” seems a nonsensical remark. But is “existence” always simply a logical predicate? Can it not sometimes be real in the sense it could tell us something that would change our idea of it? If I was to describe Superman to you and then add, “and he exists”, then surely I would be providing you with information that is useful?
A curious criticism comes from Richard Swinburne who attacks the very notion of requiring a logical argument to prove the existence of God. To require a truth of logic to prove God’s existence makes God dependent upon that logic and, therefore, God is no longer an independent being! Swinburne, here, is not denying the existence of God, but stating that God as an omnipotent, necessary being would contradict the dependence upon a logically necessary principle for its existence. But it does not require much working out to see that Swinburne is confusing “the existence of God” with “proving the existence of God”. God’s existence does not depend on the argument; only the proof does. If I somehow fail to prove that my car exists (for example, some misled individual does me the favour of stealing it) then it does not follow that it’s existence is dependent upon that proof.
In terms of logic, the argument is very clever, although many would say it is little more than a trick with language. As with all logical argument you have to have a solid premise and, as with the other arguments for the existence of God, to define God as `greater than’ in the sense of omnipotent, one, creator, necessary, and so on does mean that we are using religious language. When we are dealing with language we are inevitably sucked into the world of meaning and value. Descartes, for example, conceived of God as the perfect being and, as existence is more perfect than non-existence, then He exists; existence is God’s essence in the same way the essence of a triangle is `three-sided plane figure’. But where does this conception of God come from? What of religious believers outside of the theistic realm?
An Introduction to the Philosophy of Religion, Brian Davies, (Oxford University Press, 1993), Chapter 4.
The Puzzle of God, Peter Vardy (Fount, 1995), Chapter 9.
God, Reason and Theistic Proofs, Stephen T Davies (Edinburgh University Press, 1997), Chapter 2.
The Existence of God, ed. John Hick (Macmillan, 1964), Chapter 1 contains the original writings of Aquinas, Descartes, Leibniz, Kant, etc.