In the year 1078 a monk named Anselm of
Canterbury astonished the world by arguing that if it is even possible that
God exists then it follows logically that God does exist. Anselm's argument
came to be called the ontological argument, and it has sharply divided
philosophers ever since. The 19th century German philosopher Arthur Schopenhauer
called it a charming joke, but many prominent twentieth century philosophers
such as Charles Hartshorne, Norman Malcolm, and Alvin Plantinga think
that it's sound. Here it is. God can be defined as a maximally great being. If
something were greater than God, then that being would be God. And in order to
be maximally great, a maximally great being would have to be all-powerful,
all-knowing, and morally perfect in every possible world. Possible worlds are
simply ways the world could have been. To say that something exists in a possible
world is just to say that if the world were that way, then the thing would have
existed. For example, even though unicorns don't exist in the actual world, it seems
at least possible that they could have, so we can say that unicorns exist in
some possible world. On the other hand, a married bachelor does not exist in any
possible world because the idea of a married bachelor is logically incoherent.
It could not possibly exist. So if it is possible that a maximally great being
exists, then we can say that he exists in some possible world.
But wait; a maximally great being would not really be maximally great if it
existed in only some possible worlds. To be maximally great it has to be
all-powerful, all-knowing, and morally perfect in every possible world. So think
about it; if a maximally great being exists in any possible world, then it
exists in every possible world, and if it exists in every possible world, then it
exists in the actual world. That is, a maximally great being actually exists.
Thus the atheist has to maintain not simply that God does not exist, but that
it is impossible that God exists. Here's a summary of the ontological argument.
Steps 2 through 6 are straightforward and largely uncontroversial, but what
about point number 1? Clearly if it can be shown that the idea of a God is
logically incoherent, then the argument fails, but is the idea of a maximally
great being absurd, like a married bachelor or a square circle or the smell
of blue? This doesn't seem to be the case. The notion of the all-powerful,
all-knowing, morally perfect being that exists in every possible world seems to
be a perfectly coherent idea. But couldn't we parody this argument and
make it work for anything? Why not say it's logically possible that a maximally
great pizza exists, therefore a maximally great pizza does exist? However the idea
of a maximally great pizza is not like the idea of a maximally great being. In
the first place, there aren't intrinsic maximal values
that make pizzas great. There could always be one more pepperoni to increase
its greatness. It's not even obvious what properties make a pizza great: thin crust
or thick crust, extra cheese, anchovies? It's relative to the taste of the
consumer. In the second place, a maximally great pizza would have to exist in every
logical possible world, but that would mean that it couldn't be
eaten, so it wouldn't really be a pizza because a pizza is something you can eat. The idea of a maximally great pizza turns out not to be a coherent idea. The
idea of God, on the other hand, is an intuitively coherent idea. Therefore, his
existence is a possibility. And the ontological argument shows that if God
possibly exists, then God actually exists.
Who gets to define "maximally great"? Is the maximally great god of Iran or the maximally great god of Italy the real maximally great one?
If a dozen god claimants with magical super powers appear before you, each of them claiming to be maximally great because only he/she knows what maximal greatness is, how are you to choose?
What if the real magical maximally great entity chose to remain aloof from humans and never communicated with them? Then some lesser superpower might step in and claim to be maximally great and we would never know the difference.
I think I see why this argument isn't used much. It was poorly thought out to begin with.
Why must a maximally great being have those three particular attributes? They seem somewhat arbitrary. Why is it more "great" To exist in every possible world? Someone might see it as more great to exclusively exist in one possible world.
I don't see the maximally great being as any more intuitive than a maximally great pizza.
This does kind of worry me, because the "maximally great pizza" argument seems to be generally regarded as flawed, but I cannot see the problem with it.