Download PowerPoint No. 13 – The Ontological Argument

The Ontological Proof
• For around a thousand years, various
proofs for the existence of God have gone
by the name ‘The Ontological Proof.’
• The first person to give such a proof was
St. Anselm of Canterbury in the 11th
Century in his Proslogion.
• A Priori Proof: A proof the key premises
of which can be known independent of any
experience of the actual world.
• Anselm also provided a very influential,
short-hand definition for God.
– God = The Being than Whom none
greater can be conceived.
• Actually, Anselm gave two Ontological
Proofs.
• We shall concentrate on a simplified
version of the second one.
• This Proof, in recent years, has been
developed by such philosophers as
Charles Hartshorne, Norman Malcolm,
and Alvin Plantinga.
Anselm’s Second Ontological Proof
(Simplified)
A. If it is possible for God to exist, then God
actually exists.
B. It is possible for God to exist.
C. Therefore, God actually exists.
•
•
Now, at first glance, it would appear that
no one could take this proof seriously.
God’s mere possibility implies His
actuality?
• Many things are possible. For example,
– Polka Dot Zebras
– Striped Leopards
– Saddam Hussein – the Latrine
Cleaner
• The mere fact that these things are
possible does not mean they actually
exist.
• Why should we believe that, in the case
of God, and God alone, His possibility
implies His actuality?
• “It is possible to conceive of a Being which
cannot be conceived not to exist, and this
[Being] is greater than one which can be
conceived not to exist. Hence, if [the Being]
than which nothing greater can be
conceived can be conceived not to exist, [it]
is not [the Being] than which nothing greater
can be conceived. But, this is an
irreconcilable contradiction. There is, then,
so truly a Being than which nothing greater
can be conceived . . . , that it cannot even
be conceived not to exist, and this Being
Thou art, O Lord, our God.”
St. Anselm of Canterbury, Proslogion
• Now, this is very dense English
translated from even denser Latin.
What does Anselm mean here?
• We will restate the proof Anselm gives
here as Lemma Θ.
– A lemma is a smaller proof done
within the context of a larger proof.
– Here Lemma Θ is the proof for Step
(A.) of the simplified version of
Anselm’s Second Ontological Proof.
• Preliminaries
– God – The Being than Whom none greater
can be conceived, i.e. the Being Who is as
perfect as any being can be, the maximally
perfect Being. Some of God’s properties are
omnipotence, omniscience, and
omnibenevolence.
– Possible Reality – A reality that can be. A
possible reality might or might not be actual.
• The possible reality in which George W.
Bush is the President of the USA is actual.
• The possible reality in which Saddam
Hussein is a latrine cleaner is not actual.
• Lemma Θ is an example of the proof
type known as Reductio ad Absurdum.
– In a Reductio proof, one proves the
conclusion is true by proving its
opposite is false.
– One proves the opposite of the
conclusion is false by validly deducing
from the opposite a self-contradiction.
• For example, ‘Today is and is not
Monday.’
– Any statement from which one can validly
deduce a self-contradiction, i.e any
statement that reduces to an absurdity, must
be false.
– Therefore its opposite, in this case, the
conclusion one wants to prove, must be true.
Lemma Θ
Conclusion to Prove: If a Being, call the Being
D, is God in one possible reality, then D is God
in every possible reality.
(This statement is a more precise formulation of
Step (A.) in the simplified version of Anselm’s
Second Ontological Proof.)
1) Suppose not, i.e suppose that D is
God in some possible realities but not
in other possible realities.
(Assumption for Reductio)
2) It is greater to be God in every
possible reality instead of being God
only in some possible realities.
(Premise)
3) In every possible reality in which D is
God, one can conceive of another
being D* who is God in every possible
reality. (from A)
4) In any possible reality in which D is
God, one can conceive of another
being D* who is greater than D. (from
2 & 3)
5) In any possible reality in which D is
God, one can conceive of another
being D* greater than the Being than
Whom none greater can be conceived.
(from 4 and the Definition of God)
[(5.) is a self-contradiction]
6) Thus, if a being, call the being D is
God in one possible reality, then D is
God in every possible reality. (from 1
thru 5 by Reductio ad Absurdum)
•
Philosopher J. N. Findlay sums up the
insight of Lemma Θ (and Anselm’s
original proof):
– “It is [contrary to the demands and
claims inherent in religious attitudes
that their object] should possess its
various excellences in some merely
– “adventitious manner. It would be quite
unsatisfactory, from the religious
standpoint, if an object merely
happened to be wise, good, powerful
and so forth, even to a superlative
degree.”
J. N. Findlay, Mind, 57 (1948)
• In other words, a being who happens to be
God in one possible reality, but who is, for
example, Pee Wee Herman in every other
possible reality is not a being worth
worshipping in any possible reality.
• To be worthy of worship, to be truly God, in
ANY possible reality, a being must be
maximally perfect in EVERY possible reality.
• But, for a being to be anything in every
possible reality means the being must exist
in every possible reality.
• Thus, if a being is God in even one possible
reality, then the being is God in every
possible reality.
• Since actual reality is a possible reality, if a
being is God in even one possible reality (i.e
if it’s possible for God to exist), then God
actually exists.
• Today, thanks to the efforts of Hartshorne,
Malcolm, and Plantinga, almost everyone
concedes the truth of Step (A.) of the simplified
version of Anselm’s Second Ontological Proof.
• Today, if someone challenges Anselm’s Second
Ontological Proof, they tend to deny Step (B.)
of the simplified version, i.e. that it’s possible
for God to exist.
• “The only intelligible way of rejecting Anselm's .
. . [proof] is to maintain that the the concept of
God, as [the] Being greater than which cannot
be conceived, is self-contradictory or
nonsensical.”
Norman Malcolm, Knowledge and Certainty
• Various philosophers have take up
Malcolm’s challenge and have tried to
show the Anselmian concept of God is
self-contradictory. For example:
– Omnipotence is incompatible with
omniscience because an omnipotent
being cannot know what it’s like to be
afraid.
– Omnibenevolence is incompatible
with omniscience because an
omnibenevolent being cannot know
what it’s like to do evil.
– All these attempts tend to rest on dubious
ideas about the nature of knowledge or how
knowledge is acquired.
– Theists have reasonable, but not conclusive,
replies to these attempts to show that the
Anselmian concept of God is selfcontradictory.
• Plantinga has the final word on Anselm’s Second
Ontological Proof.
– “[I]f we carefully ponder [Step (B.)], if we
consider its connections with other
propositions we accept or reject and still find it
compelling, we are within our rights in
accepting it . . . . Hence . . . our verdict must
be as follows:
– “[Anselm’s Second Ontological Proof]
cannot, perhaps, be said to . . .
establish its conclusion, [i.e. God
actually exists]. But, since it is
rational to accept its central premise,
it does show that it is rational to
accept its conclusion. And, perhaps
that is all that can be expected of any
such argument.”
Alvin Plantinga, The Nature of Necessity