Think: A Compelling Introduction to Philosophy (22 page)

There is a story of a guru who attracted a large audience to a stadium with the promise of a definitive proof of the existence of
God. When all were assembled, he dramatically revealed the Oxford English Dictionary, and showed that it contained the word
`God'. Since the word was there, with a definition, there had to be
something answering to it. I do not know how the audience felt, or
whether any of them managed to reflect that the dictionary also
mentions Santa Claus and fairies, although admittedly qualifying
them as mythical or imaginary. But it is interesting to think how
there can be meaningful words with nothing answering to them.

The reason is that you can define a concept, but it is quite another question whether anything answers to the concept you define. You can define what you want from a partner, if you are
minded to advertise in the dating columns:

'T'houghtful person in search of fun-loving, vegetarian,
banjo-playing soccer fan, must be non-smoker.

This defines your dream partner-let us call him or her Dreamboat. But there may unfortunately not be any fun-loving, vegetarian, non-smoking, banjo-playing soccer fans. You can decide what you want to put into the description, but the world decides
whether anybody meets it. Dreamboat may not exist.

The description is perfectly intelligible. It defines a condition
that in principle someone could meet. It is just that as it happens,
nobody does meet it. One way of putting this is to say that the
terms have a sense, but no reference. You know what you mean, but
you don't know whether there is anything that answers to it. You
cannot argue from the sense to the reference, because whether
there is a reference is a question of how the world is, not to be settled in the study, or by consulting a dictionary.

It might irk you to realize that there might he nobody to answer
to your description. But you might hit on a plan to get round the
problem. Why not add a postscript, specifying that the dream person should exist? So now you advertise:

Thoughtful person in search of fun-loving, vegetarian, etc.
who exists.

And now, you might think to yourself, I have solved my problem by
definition.

Well, it is certainly true that nobody is going to call you to explain that they meet all the conditions except the last one. But then,
anybody who called you after the original advertisement also existed: `I call, therefore I am' is just as good an inference as `l think,
therefore I am'. And your adding the clause cannot have altered one
jot the chance of someone meeting the other conditions-the ones
you started with. So you have wasted your money on the last two
words. Putting `who exists' is not further specifying the dream
partner, and nor is it improving your chances that he or she in fact exists. Philosophers sometimes express this by saying that 'existence is not a predicate, meaning that adding'and exists' is not like
adding'and likes Guinness'. You are in charge of sense: you can add
what you like to the job description. But the world is in charge of
reference: it says if anything exists meeting your conditions.

With this properly understood, we can now turn to the arguments. We have already met one argument for the existence of
God, in Chapter 1: l)escartes's 'trademark' argument. It did not
seem all that strong, and in fact at a later point in his hook, Meditation V, Descartes supplemented it with another. The second was a
version of a much older argument, the ontological argument of St
Anselm (1033-1109). Anselm defines God as a being `than which
nothing greater can he conceived'. And he addresses himself to `the
fool' (from Psalm 14) who has said in his heart that there is no God:

But when this same Jool hears me say `something than which
nothing greater can be thought,' he surely understands what
he hears, and what he understands exists in his understanding; even i(hedoes not understand that it exists (in reality)...
So even the fool oust admit that something than which nothing greater can be thought exists at least in his understanding,
since he understands this when he hears it, and whatever is
understood, exists in the understanding. And surely that than
which agreater cantit) t be thought canna exist only in the understanding. For if it exists only in the understanding, it can
be thought to exist in reality as well, which is greater . . .
1'jlierefore, there is no doubt that something than which a
greater cannot be thought exists both in the understanding
and in reality.

The notable thing about this argument is that it is purely a priori. It purports to prove God's existence simply from considering the
concept or definition of God. It is like the specimen proof in mathematics, that deduces from the concept of a circle that chords
dropped from a point to opposite ends of a diameter meet at right
angles. The argument requires no empirical premises-no measuring, or results from experience.

Anselm's argument could be presented in two stages:

The concept of God is understood. Whatever is understood, exists in the understanding. So God exists in the understanding.

And then:

Suppose God only exists in the understanding, and not in
reality. Then a greater being than God can be conceived:
one that exists in reality. But God is defined as that than
which nothing greater can be conceived. So no greater
being can be conceived, by definition. But now we have a
contradiction. So our original supposition was false.

This is an argument form I describe more fully in the next chapter,
called reductio ad absurdum. Anselm has us make the original
atheistic assumption, but only en route to showing that it is false,
for it implies a contradiction.

Descartes's version of the argument trades on `perfection' rather
than greatness, but the structure is similar. God is defined as perfect, but it would be an imperfection in something with God's
other qualities not to exist: `existence is a perfection'. So existence
belongs to God's essence, and God cannot be conceived as not existing.

A monk named Gaunilo attacked the argument in Anselm's
own time. Gaunilo pointed out that if the argument were good, it
could be used to prove all sorts of conclusions that are too good to
be true: for instance, that there exists a perfect island than which
none greater can be conceived. Staying with Dreamboat, we can
work it through like this. Suppose you carefully added to Dreamboat's specifications that he or she must be not only a great lover,
but also as great a lover as can be imagined. Then you can argue in
a parallel fashion:

The concept of Dreamboat is understood. Whatever is understood, exists in the understanding. So Dreamboat exists in the understanding.

And then:

Suppose Dreamboat only exists in the understanding, and
not in reality. Then a greater lover than Dreamboat can be
conceived: one that exists in reality. But Dreamboat is defined as that lover than which no greater can be conceived.
So no greater lover than Dreamhoat can he conceived, by
definition. But now we have a contradiction. So our original supposition was false.

Dreamboat exists in reality. Wonderful! But do not rejoice too
quickly. You might also unfortunately prove by the same means
that you have as dangerous a rival as can be imagined, for Dreamboat's affections. The crucial premise will be that real rivals are
more dangerous than merely imagined ones-which they surely
are. And the ontological argument looks set to prove the existence
of the Devil-defined as that than which nothing worse can be
conceived. For if something is to be that than which nothing worse can be conceived, it had better not exist only in the imagination, for
then something worse can be conceived, namely a being that is that
bad but also really exists (notice that existence in a devil is an imperfection: it makes him worse).

Most philosophers have recognized there is something fishy
about the ontological argument-as fishy as trying to make sure
that Dreamboat exists by writing the right job description. But
they have not always agreed on just what the mistake must be. Part
of the problem is the move of treating `existence as a predicate'.
That problem is resolved by the theory we meet in the next chapter,
called quantification theory. But it is hard to be sure that this move
introduces the fatal flaw.

In my own view, the crucial problem lies in an ambiguity lurking in the comparison of`reality' and`conception'. In the argument,
things `in reality' are compared with things `in conception' (i.e. according to a definition, or in imagination or dreams), for such
properties as greatness, or perfection. This sounds simple, as if we
are comparing things in two different geographical regions, and we
know that those in one region are greater or lesser than those in the
other. It would be like asking whether chickens in Germany are
heavier than chickens in France. But in fact it is not at all like that.
Consider this sentence:

Real turkeys are heavier than imagined turkeys.

There seems to be a sense in which it is true. In that sense, imagined
turkeys weigh nothing (after all, you cannot make even a small
meal from one). But there is also a sense in which it is false, because
you can imagine a turkey heavier than any real one-a five hundred-pound turkey the size of a small barn, for example. In the
ontological argument,`God' in imagination is compared with God
in reality, like the imagined turkey compared to the real turkey, and
found to weigh less. In the argument above, Dreamboat in reality is
compared to imagined Dreamboat, and thought to be better: for
surely even quite mediocre real lovers are greater lovers than
imaginary ones! And this is supposed to contradict the definition.
But that kind of comparison does not in fact show anything contradicting the definition.

It is as if a schoolteacher required you to imagine a turkey heavier than any actual turkey. You do so: you imagine a five-hundredpound turkey. But the teacher then complains that since imagined
turkeys always weigh less than real turkeys, you have failed to imagine what she asked for. Your imagined turkey weighs nothing (you
can't eat it) and so you have `contradicted the definition' and you
get no marks. Here you would be right to feel aggrieved. It is not
you who went wrong, but the teacher.

This suggests that we must not think of `imagined turkeys' or
turkeys in the understanding' as kinds of turkey that can, in principle, be weighed against real ones but are always found to weigh
less. Yet the ontological argument requires just this kind of comparison. It is here that it fails. For even if God only exists in imagination, like Dreamboat or the five-hundred-pound turkey, it does
not follow that a greater being can be described or imagined. After
all, the description had the superlatives put into it. But unhappily
for Anselm's proof, that does not settle the question whether anything answers to it.

ELEPHANTS AND TORTOISES

The ontological argument has always seemed fishy. St Thomas
Aquinas (c. 1225-74), the greatest medieval theologian and
philosopher, did not accept it. He preferred to argue that God is
needed in order to explain the world or cosmos as we apprehend it.
This argument, the cosmological argument, has a much stronger
appeal to the imagination. There are various versions of it. They all
require identifying a way in which things in the physical universe,
things as we know them by touch and sight and the other senses,
are dependent beings. And it is then argued that dependent beings
eventually presuppose a being that is not itself dependent upon
anything, as their explanation. One version of this, and perhaps the
easiest to understand, is the first cause argument. Here is the character Demea, from Hume's Dialogues Concerning Natural Religion
(these Dialogues, first published a year after Hume's death in 1776,
are the classic philosophical analysis of traditional theological arguments, and I shall quote from them extensively in what follows):

Whatever exists must have a cause or reason of its existence, it
being absolutely impossible for any thing to produce itself or
be the cause of its own existence. In mounting up, therefore,
from effects to causes, we must eithergo on in tracing an infinite succession, without any ultimate cause at all, or must at
last have recourse to some ultimate cause, that is necessarily
existent: Now, that the firstsupposition is absurd, maybe thus
proved. In the infinite chain or succession of causes and effects,
each single effect is determined to exist by the power and efficacy of that cause which immediately preceded; but the whole
eternal chain or succession, taken together, is not determined or caused by any thing: And yet it is evident that it requires a
cause or reason, as much as any particular object which begins to exist in time. The question is still reasonable why this
particular succession of causes existed front eternity, and not
any other succession, or no succession at all. If there be no necessarily existent being, any supposition which can be firrnied
is equally possible; nor is there any snore absurdity in noth-
ing's having existed front eternity, than there is in that succession of causes which constitutes the universe. What was it,
then, which determined something to exist rather than nothing, and bestowed being on a particular possibility, exclusive
of the rest? External causes, there are supposed to be none.
Chance is a word without a meaning. Was it nothing? But
that can never produce any thing. We must, therefore, have recourse to a necessarily existent Being, who carries the reason
of his existence in himself; and who cannot be supposed not to
exist, without an express contradiction. There is, consequently, such a Being-that is, there is a Deity.