What's Wrong with

1
What's Wrong with the Ontological Argument?
2
Both Anselm Descartes

• assume
• that the existence of something than which
  nothing greater can be thought of
• is logically possible.

3
Anselms 1st ontological argument (Text, p. 73)
Something than which nothing greater can be
thought of cannot exist only as an idea in the
mind because, in addition to existing as an idea
in the mind, it can also be thought of as
existing in reality, that is, objectively, which
is greater than existing only as an idea in the
mind. If something than which nothing greater
can be thought of exists only as an idea in the
mind, then that than which something greater
cannot be thought of is that than which
something greater can be thought of, which is
impossible because it is self-contradictory. Some
thing than which nothing greater can be thought
of must exist, not only as an idea in the mind,
but in reality.
1.
2.
3.
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Criticism of Anselms 1st argument

• In the 1st premise of his 1st argument, Anselm
  says that something than which nothing greater
  can be thought of CAN be thought of as existing
  in reality.
• Is that true?
• What if the existence of something than which
  nothing greater can be thought of is LOGICALLY
  IMPOSSIBLE?

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Anselms 2d Ontological Argument (Text, pp.
73-74)
It is possible to think of something that cannot
be thought not to exist that is, a necessary
being. A necessary being something that cannot
be thought not to exist would be greater than
something that can be thought not to exist that
is, a contingent being. If something than which
nothing greater can be thought of could be
thought of as not existing, then something than
which nothing greater can be thought of would not
be something than which nothing greater can be
thought of, which is an outright contradiction
and thus absurd. Something than which nothing
greater can be thought of has such a high degree
of existence, that is, necessary existence, that
it cannot be thought of as not existing, that is,
its nonexistence is impossible.
1.
2.
3.
4.
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Criticism of Anselms 2nd argument

• In the 3rd premise of his 2nd argument, Anselm
  says that thinking that something than which
  nothing greater can be thought of as not
  existing is an outright contradiction and thus
  absurd.
• Is that true?
• What if the existence of something than which
  nothing greater can be thought of is LOGICALLY
  IMPOSSIBLE? In that case, the statement,
  Something than which nothing greater can be
  thought of exists, would be necessarily false,
  and its negation (Something than which nothing
  greater can be thought of does not exist) would
  be necessarily true.

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Descartes' Version of the Ontological Argument
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1. If the nonexistence of God (an infinitely
perfect being) were possible, then existence
would not be part of Gods essence (that is,
existence would not be a property of the
divine nature). 2. If existence were not part of
Gods essence (that is, a property of the
divine nature), then God would be a
contingent (rather than necessary) being. 3. The
idea of God as a contingent being (that is, the
idea of an infinitely perfect being with
contingent rather than necessary existence)
is self-contradictory. 4. It is impossible to
think of God as not existing. 5. The
nonexistence of God is impossible.
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Criticism of Descartes' Version
Like Anselm, Descartes (in his 2d and 4th
premises) assumes that Gods existence must be
either necessary or contingent. And since it
makes no sense to say that Gods existence is
contingent (3d premise), Descartes (validly)
concludes that the existence of God must be
necessary (because His nonexistence is
impossible). However, again like Anselm,
Descartes does not consider the possibility that
Gods existence might be IMPOSSIBLE. If Gods
existence is impossible, then His existence is
NEITHER contingent NOR necessary. If Gods
existence is impossible, then God cannot exist.
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To develop this point,

• lets look at another version of the ontological
  argument.

1. If a Perfect Being exists, then its existence
is necessary. 2. If a Perfect Being does not
exist, then its existence is impossible. 3.
Either a PB exists or it doesnt. 4. Either the
existence of a PB is necessary, or it is
impossible. 5. The existence of a PB is not
impossible. 6. The existence of a PB is
necessary.
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1. P ? N 2. ?P ? I 3. P ? ?P 4. N ? I 5.
?I 6. N

(Is Premise 5 true?)

That is, is it possible that the existence of a
Perfect Being is IMPOSSIBLE?
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How might it be argued
that the existence of God is impossible?
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Heres an argument against Premise 5 in the
preceding argument
If there is dysteleological evil (pointless,
purposeless, or meaningless pain suffering),
then the existence of a Perfect Being is
impossible. There is dysteleological evil. The
existence of a PB is impossible.
1.
?
2.
3.
?
(Can the 2nd premise in this argument be known to
be true or false?)
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Whats the outcome of all this?

• There is a dispute among rational people as to
  the existence or non-existence of dysteleological
  evil. That is, it cannot be known whether DE
  exists or not.
• That means that it might or might not exist.
• Since DE might exist, since the existence of DE
  would make the existence of a PB impossible, it
  follows that
• it is possible that the existence of a PB (God)
  is impossible ( that the non-existence of a PB
  is possible).
• Therefore, the ontological argument does not
  prove the existence of God.