What was Anselm saying here?
Well, his first idea had to do with the idea of God.
What's our concept of God?
What is it that we're thinking of when
we're thinking of a god?
He said: "God is something that than which
no greater can be thought."
What did he mean by this?
Well, his idea was that when we think of God,
we're thinking of a maximally good thing, a thing such
that you can't think of any better thing.
To put it another way, if you think of something,
then you also think: "well, it could
have been a bit better than it is,"
you're not thinking of God.
It's part of the idea of God that He's maximally good.
He's the very best way He could be.
He couldn't be any better than He is.
That was Anselm's first idea.
His second idea concerns existence and nonexistence.
And it's perhaps best illustrated with some diagrams.
According to Anselm, there are things
that exist in the understanding.
You can think of these as things that we think about
or have thought about.
And then there are things that exist in reality.
You can think of these as, well, just things that exist.
And there may be some intersection
between these sets of things or these categories of things.
In the intersection, there would be things that we think about
or have thought about and also exist in reality.
So for example, in the category of things
that exist in the understanding that don't exist in reality,
we might put, if we were thinking the way Anselm thinks,
the Tooth Fairy.
We might also put Bigfoot.
We might put Captain Kirk in there, Sherlock Holmes,
and so on and so forth.
In the category of things that exist in the understanding
and exist in reality, we might put you, me, MIT, Barack Obama,
and so on and so forth.
These are things that are thought about,
that we think about, and that also exist in reality.
And in the category of things that exist in reality
but don't exist in the understanding, well,
it's hard to name particular things,
because as soon as I name those things,
we'll be thinking about them.
And the things in this category are never thought about.
But we can maybe kind of gesture at those things.
Maybe such things include stars that have never been seen.
Maybe in there are most of the fish in the ocean.
After all, most of the fish in the ocean
live and die their whole lives and are never
thought about by anyone or anything.
Anselm's next idea had to do with potential greatness.
Let's start not by looking at God,
but by looking at the Tooth Fairy.
The Tooth Fairy exists in the understanding
although not in reality.
How awesome is the Tooth Fairy?
Well, the Tooth Fairy is pretty awesome thing.
My children still get excited about the Tooth Fairy.
Maybe if you have children, you'll know what I mean.
But now imagine how awesome would the Tooth Fairy
be if the Tooth Fairy existed both in the understanding
and in reality-- if we both thought about the Tooth Fairy
and the Tooth Fairy really existed.
Well, I say the Tooth Fairy would be very, very awesome
indeed-- really awesome.
After all, this would be a real Tooth Fairy.
This would be a Tooth Fairy who really
was putting $5 bills underneath your pillow
at night-- very exciting thought.
How much more excited would I be about the Tooth Fairy
if the Tooth Fairy was real?
I would be very excited indeed.
Similar things can be sad for, say, Bigfoot.
Bigfoot-- how scary is Bigfoot?
I don't know.
I'm not very scared by Bigfoot.
I suppose it's a pretty scary thought.
A lot of how scared you are by Bigfoot
depends on what Bigfoot movie you've most recently seen.
Let's call Bigfoot pretty scary.
Now, imagine that Bigfoot, who exists in the understanding
but not in reality, existed both in the understanding
and in reality.
Imagine that the Bigfoot that we were thinking about really
existed.
How scary would that be?
It would be much, much more scary.
I would be genuinely scared if I were wandering
through the wilderness of Colorado
and I knew that Bigfoot really existed.
OK.
So often, things that exist in the understanding
but not in reality would be better, more impressive,
more awesome, more scary if they existed
in both the understanding and reality.
And Anselm said something like that is true of God.
Suppose God existed in the understanding,
but not in reality.
Here He is-- God, there in the understanding
but not in reality.
How great would He be?
Well, pretty great.
After all, we're thinking about God.
It's a pretty great thing.
But now suppose that God existed in the understanding
and in reality.
How great would God be then?
God would then be extraordinary.
After all, God, if He existed in the understanding
and in reality, would have created us all,
would have truly true omnipotence,
would have made the universe around us,
would be interfering-- well, how much he interferes, of course,
depends on your theology-- but would be the kind of creature
who we should think of as really, really, really great.
God would be better if He existed in the understanding
and in reality than if He just existed in the understanding.
But what does that mean?
It means that God can't exist in the understanding,
because remember, Anselm said it's part of our idea of God
that we can't imagine Him being any better than He actually is.
If you're thinking of something that
could be better than it is, then you're not thinking of God.
So for example, if a fool says, I'm
thinking of God as existing in the understanding
but not in reality, then the fool is not thinking of God.
God can't be in the understanding
but not in reality.
But God, of course, is in the understanding.
The fool claims to be thinking of God.
We can think of God.
It's easy to think of God.
We just think of a being such that no greater being
can be imagined.
And so God must be there in the understanding and in reality.
He must be real.