Aquinas and the Cosmological Arguments: Crash Course Philosophy #10 Video Lecture | What is Philosophy - Science or Religion? - Self Help Learning

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Nothing gets people talking like proving the existence of God -- just look at the comments on our last video.
And that is what Anselm of Canterbury did.
He claimed, in the 11th century,
to have come up with deductive proof of God’s existence, through what we now know as the ontological argument.
And, if there was such a thing as a social
network of medieval Christian philosophers
back then, it was positively abuzz with the
news. For a long time. Because, almost 200
years later, Italian theologian and philosopher
Thomas Aquinas encountered Anselm’s argument.
But, like many others, he just didn’t buy
it.
Aquinas did believe in God. It was just that,
as a philosopher, he felt that it was important
to have evidence for your beliefs. He knew
that if he was going to dismiss Anselm’s
argument, he’d need to come up with something
better. So, he set out to construct five arguments
that would prove God’s existence, once and
for all.
Yeah, five. Apparently, he was concerned one
wasn’t going to do it, so he figured that,
out of five, one was bound to stick.
His first four arguments are known together
as the cosmological arguments, as they seek
to prove God’s existence through what he
argued were necessary facts about the universe.
So, in keeping with the method that we discussed
in our very first episode, we’re going to
examine these first four arguments of Thomas
Aquinas -- and really try to understand them.
And then we’ll consider their merits…
...and their weaknesses.
[Theme Music]
Maybe the most striking thing about the cosmological
arguments of Aquinas, at least to modern eyes,
is that some of them are firmly based in the
natural world. Even though he lived in a pretty
unscientific time, Aquinas argued for the
existence of God through his understanding
of science, and with the help of what he thought
was physical evidence.
For example, the first of his cosmological
arguments is known as the Argument from Motion.
In it, Aquinas observed that we currently
live in a world in which things are moving.
And he also observed that movement is caused
by movers -- things that cause motion. Aquinas
was convinced that everything that’s moving
must have been set into motion by something
else that was moving. By this logic, something
must have started the motion in the first place.
Otherwise, you’d be stuck in a philosophical
quandary known as an infinite regress.
You get an infinite regress when, in a chain of
reasoning, the evidence for each point along
the chain relies on the existence of something
that came before it, which in turn relies
on something even further back, and so on,
with no starting point.
Basically, Aquinas thought the very idea of
infinite regress was absurd, logically impossible.
Because, it implied that any given series
of events began with…nothing. Or, more accurately,
never really began. Instead, it could have
been going on forever.
In the case of physical motion, Aquinas wanted
to trace the cause of the movement he saw
in the world all the way back to its beginning.
And he figured there MUST have been a beginning.
Otherwise, for him, it would be like watching
these blocks fall, and being told that nothing
ever pushed over the first block. Instead,
they had always been falling down forever,
backward into eternity. There must have been
a time when nothing was in motion, Aquinas
thought, and there also must’ve been a static
being that started the motion. And that being,
according to Aquinas, is God – the Unmoved
Mover.
So his Argument From Motion ran something
like this:
Objects are in motion
Everything in motion was put into motion by
something else
There can’t be an infinite regress of movers
So there must have been a first mover, itself
unmoved, and that is God
Now, the second cosmological argument
of Aquinas was a lot like his first one.
Here, he proposed the Argument from Causation, and it, too, sets out to avoid the problem of an infinite regress.
But instead of it explaining the motion of
objects, it set out to explain causes
and effects, in general, all over the universe.
The argument went along these lines:
Some things are caused
Anything that’s caused has to be caused
by something else (since nothing causes itself)
There can’t be an infinite regress of causes
So there must have been a first causer,
itself uncaused, and that is God
Just like with the Argument from Motion, the
point here is pretty simple: Effects have causes.
If you think about how you wound up watching this
video, you can trace the line of causation back,
from moment to moment. If you think about it long enough, you can probably go pretty far back.
But Aquinas said, again: It can’t go back
forever. There had to be a First Thing that
started off the chain of causes and effects.
And that Thing is God.
Argument number three was the Argument from
Contingency. And we should step back and get
a little background for this one. In philosophy,
we often distinguish between necessary beings
and contingent beings. A contingent being is,
simply put, any being that could have not existed.
That includes you. Sure, you
do exist, but you could not have.
If you had never been born, the world would go on. And
yes, things would be different – we’ve
all seen It’s A Wonderful Life – but the
world would go on. Instead, your existence
is merely contingent on the existence of other
things. In your case, you only exist because
a certain sperm met a certain egg and swapped
some genetic information. You’re basically a fluke.
But what does that have to do with God? Well,
again, Aquinas believed that there had to
be something that prevented an infinite regress
of contingency. That would mean that the contingency
on which everything existed would just keep
going back in time. And we can’t have a
world where everything is contingent, Aquinas
said, because then -- by definition -- it
all could easily have never existed. So he
needed at least one necessary being –
a being that has always existed, that always
will exist, and that can’t not exist, in
order to get everything going. And that necessary
being is God.
Aquinas spelled out the reasoning of his Argument
from Contingency this way:
There are contingent things
Contingent things can cause other contingent
things, but there can’t only be contingent
things
Because that would mean that there’s an
infinite regress of contingency, and a possibility
that nothing might have existed
An infinite regress is impossible
So there must be at least one necessary thing,
and that is God
Let that marinate in your brain for a minute
while unpack the next argument.
This one is built on the idea that we simply need a measuring stick in order to understand the value of things.
Good/bad, big/small, hot/cold – none of
these concepts can exist in isolation.
If you go out for a walk and you see an animal,
and it’s like this big, that animal would
be on the small side if it turned out to be
a dog. But if it were a rat, that would be HUGE.
How do we know? Because we gauge the size
of things in terms of other things.
The same idea applies to more abstract concepts, like your grades. How do we know that an A is good?
Because it’s at the top -- we know that there are grades lower than an A, but nothing higher.
And Aquinas thought that all of our value
concepts would just be floating randomly in
space if there weren’t some anchor – something
that defined the value of everything else,
by being perfect – and that, again, is God.
This is how Aquinas developed Number four,
known as Argument from Degrees.
Properties come in degrees
In order for there to be degrees of perfection,
there must be something perfect against which
everything else is measured
God is the pinnacle of perfection
Ok, so we’ve considered Aquinas’ four
cosmological arguments. But remember, that’s
only step one. The next, and equally important
step in philosophy, is critical evaluation.
So what do we make of ‘em?
As philosophers, if you think an argument
is flawed, it’s your job to try and figure out why.
And by and large, philosophers – theists
and atheists alike – have been relatively
unimpressed by these four, having found many
problems in them.
For one thing, these arguments don’t seem
to establish the existence of any particular god.
Even if the arguments are correct, it
doesn’t look like Aquinas gets us to the
personal, loving God that many people pray
to. Instead, we’re left with unmoved movers
and uncaused causers who seem to have little
in common with the God of Abraham, Isaac,
and Jacob ... the God who feels emotions, and
cares about his creation, and answers prayers.
Basically, this objection says that
Aquinas’ god is so far removed from the
god that theists actually believe in, that
it doesn’t help anything.
But maybe you’re happy just believing
someone’s out there. That’s fine.
But then how about multiple someones?
Because – guess what – Aquinas’ arguments
don’t rule out polytheism. There’s nothing
in any of his arguments to prove that God
isn’t actually, like, a committee. Aquinas’
cosmological arguments also don’t prove
the existence of a sentient God. So, it might
be an old guy with a beard. It might be six
old guys with beards. But it also might be
an egg, or a turtle, or just a big block of
stone.
These observations have made some philosophers
uncomfortable with Aquinas’ ultimate conclusion.
But there are two objections that are thought
by some to be real nails in its coffin.
The first is simply that Aquinas was wrong
in his insistence that there can’t be an
infinite regress of anything. Aquinas takes
it as a given that there had to be a starting
point for everything -- whether it’s the
movement of objects, or causes and effects,
or contingent beings being created. But it’s
unclear that this is true, or why it has to be true.
If infinite regress can be possible, then
Aquinas’ first two arguments fall apart.
But perhaps the most significant charge made
against Aquinas’ arguments is that they’re
self-defeating -- that is, they actually prove
themselves wrong.
For example: If Aquinas is right that everything
must have been put in motion by something else,
and everything must have a cause other
than itself, then it seems that God should
be subject to those same stipulations. And
if God is somehow exempt from those rules,
then why couldn’t other things be exempt
from them too? If they can exist without God
being responsible them, then we don’t need
God to establish things in the first place.
All right, I’ve given you a lot to think
about.
So before we close, let’s pause and remind
ourselves about a couple of things.
First, you can accept a conclusion but reject
an argument. So you might agree with Aquinas
that God exists, but think none of his arguments
prove it.
Second, if you disagree with an argument,
you don’t get to just say, “yeah, you’re wrong.”
You have to give a counterargument. What did Aquinas get wrong, and how can you do better?
Why are your reasons superior to his?
Remember, philosophy is a dialectic.
Yes, Aquinas has been dead for centuries. But he started a conversation. And you get to participate
in that when you engage with his arguments, and offer your own, either in an effort to help him out
– by fixing flaws in his arguments while preserving his conclusion – or by refuting his entire project.
This is what it means to do philosophy – to engage with arguments about stuff that matters.
And whether or not there’s a God seems to matter quite a bit, particularly in the lives of theists.
Today we’ve learned about cosmological arguments,
and considered four of them. Next time, we’ll
look at Aquinas’ fifth argument, the teleological
argument.
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