Download Anselm`s Ontological Argument

ONTOLOGICAL ARGUMENTS
Ontology means “relating to being or existence”.
Ontological arguments are different to other arguments for God’s
existence, because they are a priori. Rather than starting from some sort
of experience of the world, they rely solely on the definition of God.
Ontological arguments claim that if you understand what the word God
means, then you know that he exists, because existence is part of the
definition of God. The proposition “God exists” is therefore analytic and
is necessarily true.
We will consider the first example of an ontological argument, put
forward by St Anselm (1033-1109), the objections to it, and then how it
has been modified by other philosophers up to the present day.
Anselm’s Ontological Argument
St Anselm was trying to write a single argument for God’s existence that
didn’t rely on any other arguments or assumptions. His writing is in the
form of a prayer addressed to God, but we can easily set it out in
standard form.
He starts from a definition of God:
1. God is that than which nothing greater can be conceived
2. It is greater to exist in understanding and in reality than in the
understanding alone.
3. Therefore, God must exist in reality as well as in the
understanding.
If God only existed in our minds, then he wouldn’t be God, because
there is something greater than an idea of God- actual God. So as long
as we have a concept of God, and that concept involves being the
greatest, then God must exist in reality.
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Gaunilo’s Criticism of Anselm
Shortly after Anselm’s first argument was published, another monk
named Gaunilo wrote this reply:
“It is said that somewhere in the ocean is an
island…and they say that this island has an
inestimable wealth…it is more excellent than all
other countries…Now if someone should tell
me that there is such an island, I should
easily understand his words… But suppose
that he went on to say…’since it is more
excellent not to be in the understanding
alone, but to exist both in the understanding
and in reality, for this reason, the island must
exist’.”
Gaunilo is pointing out that Anselm’s reasoning can be used to prove
that anything exists, as long as we claim it is the greatest or the most
excellent. But we don’t think that these things must really exist. So we
can’t rely on this reasoning to work for the existence of God. We need
empirical evidence to prove that this most excellent island really exists,
so we need similar evidence on which to base our belief in God.
Anselm’s Response to Gaunilo
In response to Gaunilo, Anselm claims that his reasoning only works for
God. This is because everything else is contingent.
Contingent things are limited and it is possible for them not to exist, so
we don’t know if they exist until we check.
But God is different, because his existence is necessary.
We can imagine islands that don’t exist, because existence isn’t an
essential part of being an island. But we can’t imagine God not existing,
because it is an essential part of God that he exists.
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Anselm can argue for this claim like this:
1. God is that than which nothing greater can be conceived.
2. A being which cannot be conceived not to exist is greater than one
which can be conceived not to exist.
3. Therefore, God cannot be conceived not to exist. “That which can
be conceived not to exist is not God”
Since Anselm, many philosophers have proposed similar ontological
arguments, and many others have criticised and discussed them:
Descartes’ Ontological Argument
1.
2.
3.
4.
5.
I have the idea of God
The idea of God is the idea of a supremely perfect being
A supremely perfect being has every perfection
Existence is a perfection
Therefore, God exists
Descartes is saying that it is part of the concept of God that he exists.
Triangle
= 3 sides
Unicorn =
horse+horn
God = exists
Having three sides is part of the concept of a triangle. So it is impossible
for a triangle not to have three sides. In the same way, existence is part
of the concept of God, so it is impossible for God not to exist. God’s
existence is necessary.
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Leibniz’s Addition to the Ontological Argument
Leibniz accepted Descartes’ argument, but felt that it was incomplete.
Leibniz saw the potential for problems with a list of ‘perfections’. If we
allow anything to qualify as being a perfection, we could end up with a
set of perfections that are incompatible with each other (as we saw in
handout R1).
So Leibniz argued that a perfection must be simple and positive. That
is, it can’t be defined in terms of anything else, and it can’t be defined as
the negative of anything else. This means each perfection is selfcontained and doesn’t place a restriction on any other perfection, and
therefore they couldn’t be incompatible with each other. So it is possible
for the perfections to co-exist in one being. So a supremely perfect being
is possible.
So Leibniz’s ontological argument is the same as Descartes’, but with
the addition of a premise: “A perfection is a simple quality which is
positive and absolute”.
ISSUES WITH ONTOLOGICAL
ARGUMENTS
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Hume’s Objection to Ontological Arguments
As an empiricist, Hume thought that synthetic knowledge could
only be gained through sense experience, not through reason
alone. So any argument that attempts to prove a synthetic truth
(that God exists) by using a priori reasoning should, using
Hume’s fork, be disregarded.
Anselm and Descartes seem to have been treating the
proposition “God exists” as an analytic one. But Hume says
that it must be synthetic, because it is making a claim about
what really exists in the world.
Hume continues:
“Nothing that is distinctly conceivable involves a contradiction. Whatever
we conceive as existent, we can also conceive as non-existent. There is
no being, therefore, whose non-existence implies a contradiction.
Consequently, there is no being whose existence is demonstrable.”
Hume’s main point here is that because we can imagine God not
existing, it is not contradictory to claim that he doesn’t exist. So his
existence is not logically necessary, as Anselm and Descartes have
claimed.
Philosophical Skills…
Most propositions consists of a subject and a predicate.
The subject is what the proposition is about.
The predicate gives us information about the subject.
For example, in the sentence “the cat sat on the mat”,
‘the cat’ is the subject and ‘sat on the mat’ is the predicate.
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Kant built on Hume’s ideas, putting forward two main criticisms:
Kant’s First Criticism – existence is not a property of God
“Existence is obviously not a real predicate.”
Descartes and Anselm both assume that existence is a predicate. Kant
says that real predicates add something to our concept, they give it new
properties. But ‘existence’ doesn’t do this.
Kant makes his point by asking us to imagine 100
Thalers (coins). We can imagine them being gold,
round, heavy and old. These are all genuine
predicates because they change our
understanding of the coins. But if we then add
“they exist”, nothing about our concept changes.
There is no difference between the idea of ‘100
coins’ and ‘100 coins that exist’.
So, ‘existence’ is not a real predicate. If Kant is right, then ontological
arguments fail because they claim that existence is part of the definition
of God. If existence is not a predicate then it can’t be part of the
definition of God, or anything else.
Kant’s Second Criticism – even if existence is a property of God, that
doesn’t mean he exists
In his second criticism, Kant temporarily accepts that existence is a real
predicate, along with Descartes’ claim that “God necessarily exists” is an
analytic statement. He argues that even if it is analytic, it doesn’t mean
that God exists in reality.
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For example, the definition of a unicorn
is a horse with a horn. So it is
necessarily true that unicorns have
horns. Any unicorn that we ever
encounter must have a horn. If it didn’t,
it wouldn’t be a unicorn.
But this doesn’t show that there are
any unicorns in the world.
All it shows is that if there are any, they will necessarily have horns.
Kant says that the same reasoning applies to God. Necessary existence
may be part of the definition of God. So we know that if God exists, then
he exists necessarily. But this doesn’t tell us whether he does exist in
reality.
Descartes can define God however he likes. The definition can only ever
tell us about our concept of God. Nothing in the definition can ever
bridge the gap and tell us about what exists in the real world. Like Hume,
Kant thinks only empirical evidence can do that.
MODERN ONTOLOGICAL ARGUMENTS
In recent years, several philosophers have tried to revive Anselm’s
original argument. Two of these are Norman Malcolm (1911-1990) and
Alvin Plantinga (1932- ).
Philosophical Skills…
If something is necessarily true, then it is logically impossible or selfcontradictory for it to be false.
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For example, the statement “all bachelors are unmarried” is necessarily
true because the opposite “some bachelors are married” could not
possibly be true.
If something is necessarily false, then it is logically impossible or selfcontradictory for it be true.
For example, the statement “my mother is younger than me” is logically
impossible. Just by understanding the concepts of the terms “mother”
and “younger”, we know that it must always be false, without knowing
anything about the world.
Malcolm’s Ontological Argument
Malcolm starts by considering every possible situation regarding God’s
existence:
A. God’s existence is necessarily false (logically impossible)
B. God’s existence is contingently false (logically possible but
happens to be false)
C. God’s existence is contingently true (logically possible and just
happens to be true)
D. God’s existence is necessarily true (logically necessary- had to be
true)
Then his argument proceeds:
1. God’s existence is either necessarily false, contingently false,
contingently true or necessarily true. (One, and only one, of claims
ABCD must be true)
2. B and C cannot be true because God has no beginning or end so
cannot be contingent.
3. A cannot be true because God’s existence is not logically
impossible (self-contradictory)
4. Therefore, D must be true – God necessarily exists
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Response to Malcolm
The problem lies with premise 3. Many people claim that the very idea of
God (a timeless, omnipotent, benevolent being that exists) is logically
impossible. We have already seen examples such as the paradox of the
stone and the problem of evil that question the existence of a being with
these properties. If the existence of God is self-contradictory, then
statement A is true, and statement D must be ruled out instead.
Plantinga’s Ontological Argument
Plantinga uses a similar strategy to Malcolm. But he bases
his argument on the idea of possible worlds.
A possible world is the way the world could have been. Some
possible worlds are the same as this one apart from one small detail.
Others are completely different and have flying pigs, or no life at all. But
some things cannot be true in any possible world. For instance, there is
no possible world where triangles have two sides, 2 +3 = 4 or bachelors
are married.
Plantinga’s version takes much the same form as earlier ontological
arguments, but he changes talk of necessary and contingent existence
to a discussion of possible worlds:
1.
2.
3.
4.
God is the being with the maximal greatness
There is at least one possible world in which God exists
It is greater to exist in all worlds than to exist only in some
So, because God has maximal greatness, he must exist in all
possible worlds
5. Therefore, God exists in the actual world
Responses to Plantinga
The first response is to deny premise 2. Like in the response to Malcolm,
we can deny that the existence of God is possible at all. If the concept of
God is incoherent, then there is no possible world in which he could
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exist. The existence of a being with God’s properties is as contradictory
as the existence of a triangle with 4 sides.
The second response is to deny premise 3. Although it might seem
obvious that existing is greater than not existing, this is not necessarily
the case. It is tempting to think that something that doesn’t exist has
zero greatness, which is obviously less than the value of something that
does exist. But something that doesn’t exist doesn’t have any value of
greatness, not even zero. So, it isn’t greater to exist than not to exist, or
to exist in more worlds rather than fewer.
Final Thoughts…
Is existence a real predicate?
Is the idea of God’s non-existence self-contradictory?
Is the claim “God exists” analytic or synthetic?
Are the modern versions any more convincing than Anselm’s original
argument?
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