Descartes’s
Attempts to Prove that God Exists
1.
The Argument from the Innate Idea of God
(3rd meditation)
At
this stage in the Meditations Descartes is sure only that he is a thing
that thinks, i.e. that has a mental life, including doubts, dreams, hopes,
thoughts, pains, etc. He thinks of
himself as a non-physical container of ideas, beliefs, sensations, etc.
One of these ideas is the idea of God, a perfect being.
How did it get there? There
are only three possible ways to get an idea:
a) experience
("adventitiously," meaning that the idea comes into
the mind from outside b) making it
up by combining elements of other ideas ("factitiously,"
meaning that the idea is manufactured in the mind from material already there), and c) having them innately, i.e. from
birth. He has never experienced a
perfect being, so a is ruled out. He
has never experienced anything perfect, so his idea of a perfect being cannot
just be constructed out of parts of other ideas. (Or: the idea of God is the idea of an infinite being, and no
amount of addition of lesser ideas could ever reach infinity.)
Think of people living in darkness all their lives coming up with the idea of
light--it cannot be done. Just as light is not simply the absence of
darkness, so too God is not simply the absence of limits or imperfections.
We could not generate such an idea from our own limited
imaginations and experiences.
Therefore, this idea of God must be innate.
Who or what could have placed it in his mind?
Only a perfect being could create the idea of perfection
(because, Descartes claims, there must be as much reality in the cause of an
idea as there is in the thing that it is an idea of), therefore a
perfect being must have planted this idea in his mind.
So, a perfect being, i.e. God, must exist.
Objections:
I. Does the idea of a
perfect being really exist, or is this really just empty talk?
II. Couldn’t we have made
the idea up, for instance by comparing people of different levels of goodness
and imagining one that would beat all others in such a competition?
III. Even if there is an
innate idea of a perfect being, why must its cause be perfect?
Couldn’t it in fact be the product of evolution or chance, just as a
monkey with a type-writer might happen to produce the complete works of
Shakespeare?
IV. Who says this perfect
being, if it exists, is God and not Allah or Zeus or Godzilla?
V. If all I know is that I
am a thinking thing, that might be deceived every second by an evil demon, how
do I know that what looks like a logical argument to me is not in fact a load of
baloney?
VI. Couldn’t we get the
idea of infinity by combining finitude (limitedness) with negation?
2.
The Cosmological Argument (3rd
meditation)
I
exist. There must be some reason
why I exist, or cause of my existence. What
could this be? If I had created
myself, I would know about it. If
it was my parents, or a mad scientist in a laboratory, or anything in the
natural world, then what created the natural world and the laws of nature?
Nothing natural can create itself. So
there must be something beyond the natural world, something supernatural.
This is God.
Objections:
I. Why couldn’t things
just exist for no reason?
II. Why must the
supernatural creator of all things be God?
III. Why does God exist?
IV. See Argument 1, Objection V.
V. The very
existence of the world can seem to be a mystery, a wonder, or a miracle.
The cosmological argument seems to say, "No mystery. God." But isn't
God supposed to be a mystery, to surpass human understanding? Isn't the
world a miracle, a divine mystery, from a religious point of view? If so,
then the choice is not between mysterious atheism and non-mysterious theism.
The choice is between mysteries, one atheistic and one not. The theistic
option will then not be preferable on the basis of its non-mysteriousness.
(This objection is related to Objection III above.)
3.
The Ontological Argument (5th
meditation)
The
idea of God is the idea of a perfect being.
A perfect being is one that has every perfection.
Existence is a perfection. Therefore,
God has the property of existence, i.e. He exists.
Objections:
I. There must be something
wrong with this argument, because otherwise we could substitute the words
‘Bob’ and ‘50-foot walking jelly doughnut’ for ‘God’ and
‘being’, to prove the existence of a perfect 50-foot walking jelly-doughnut
called Bob. This would be
ridiculous.
II. Existence is not a
perfection. Being good or eternal
might be perfections, but to be good you first have to be.
Existence is a necessary prerequisite for having perfections.
It is not itself a perfection.
III. See Argument 1,
Objection IV.
IV. See Argument 1,
Objection V.