To defeat the third and most powerful skeptical argument from the first, uh, meditation, the evil demon, Descartes's gonna prove that God exists. Nothing up my sleeves. I have no props. I will prove that God exists right now. This is a very common, uh, hobby for philosophers.
For a long, long time, this is something that, that philosophers like doing. This proof, uh, it, it, the, the meditations, this book actually has two proofs. One of them is terrible. Uh, it uses a lot of medieval ideas you have to buy into to get it going, and we're not gonna touch that one. The other one is one that Descartes basically plagiarized.
Um, it's known as the ontological proof. It was created by a 12th century, I believe, monk named Saint Anselm. Uh, I used to drive by a church, of Saint Anselm Church. I was wondering if they, uh, chanted this proof. I kinda doubt it, but I imagined them doing it.
Uh, and it is entirely a priori. There are some empirical proofs, but Descartes can't have that because he cannot know there's a world outside of him yet. He needs God to prove that, so he can't use that to prove God. This, uh, he can... Oh, the only resources he has at this point are the three things he has in his foundation.
That's it, his existence, his essence as a thinking thing, and his ideas, every one of which could be wrong. From those, he's gonna build a God, and not only from those, but actually only from one, only from his ideas. The proof begins from the fact that Descartes has ideas in his head. I have an idea that I'm seeing a wall. I don't know if there really is a wall.
I don't know if walls exist. I don't know if a world exists, but I know that I have an idea of a wall. Now, the first thing that Descartes points out is that ideas have essences. We don't know if the thing that they're about has existence. I don't know if walls exist, uh, but I do know that there's a thing that is a wall.
So when we look at these ideas, uh, we do not know if they are true in the sense that anything outside of my head corresponds to them. We do not know if anything outside of me is causing them. It could be a dream, it could be the Matrix, it could be a demon. But we do know that even if they don't have existence, they do have essence. Unicorns don't exist.
I hope that doesn't shock anyone. I hope I didn't burst any bubbles there. But they do have an essence. The essence of a unicorn is a horse with a horn. If the idea of a unicorn did not have an essence, then I could not even deny their existence, 'cause what would it be that I'm denying the existence of?
If I didn't know what I was talking about when I was talking about unicorns, and you didn't know what I was talking about, then saying they don't exist would be meaningless. If I said flubblablas don't exist, that doesn't mean anything because it d- doesn't have an essence. You don't know what I'm talking about. But because you know what unicorns are, horses with horns, you know what I mean when I say they don't exist. I can only deny existence of them because they have essence.
There is a meaning, a definition. There are necessary properties to this idea, even though they're only an idea. There's nothing beyond an idea to them. It still has an essence to them, and it's an essence that I can't control. I can't change the meaning of unicorns.
That's just what they mean. Whether they exist or not, th- they, they're in my, my head, and these essences can have, uh, implications. They can entail other properties. Because it has one property, that can mean it has other ones too. So his favorite examples are always geometrical.
Uh, he has the idea of a triangle. Uh... The idea of a triangle is very easily a shape with three sides. That's the definition of a triangle. He doesn't know if there are any triangles in the world.
All he knows, he has the idea of it, and yet that idea has necessary properties. It has an essence. It has to have three shape, three sides, or it's not a triangle. If I say, "I just saw the, the rarest thing. I saw a four-sided triangle," you would say, "No, you didn't.
That's not a triangle." I can't see one because it has to be three sides to be a triangle. But it's not just three sides. Once you have that essence, there are further properties you can derive from that if you know much about geometry, like I don't, but like Descartes did. Any shape with three sides, uh, connected, the internal angles must add up to 180 degrees. That's a law of geometry Again, it doesn't matter if there is no triangle in the universe.
It doesn't matter if there never has been a triangle. If there ever will be a triangle out there, the idea has necessary properties to it. Whether there's anything like that correspond to it is irrelevant. The idea of a triangle has an essence. It has three sides, and that essence has necessary properties, like the internal angles adding up to 180 degrees.
Purely a priori, purely about the idea, we are still restricted. You can't choose to have a triangle whose internal angles add up to 179 degrees because then it wouldn't be a triangle. It must have this property. Okay, third step. Among my ideas is an idea of God.
What is the essence of that idea? The essence of the idea of God, according to this proof, is to be a supremely perfect being. A supremely perfect being isn't just perfect in one way or another way, but is a being that is perfect in all ways, is completely perfect, is absolutely perfect, has all possible perfections. Now, that essence, just like the essence of three sides, has implications. That entails other properties.
The three sides entails 180 degrees. The definition of all possible perfections means that any perfection you could come up with, God must have it. So in order to flesh out the definition of what God is, all you have to do is come up with, with possible perfections. If you come up with a possible perfection, God has it because the idea of God is to have all possible perfections. If you're thinking of a God that does not have a possible perfection, you're not thinking of a God any more than a four-sided triangle is a triangle.
So what are some possible perfections? Well, omniscience, knowing everything, perfect knowledge. Yep, okay. Perfect knowledge is a perfection. God is the being with all possible perfections, therefore God is omniscient.
Omnipotence, perfect power. God is the being with all possible perfections. Perfect power is a perfection. God is omnipotent. Omnibenevolence, perfect goodness.
Possible perfection, God has it. Perfect existence. Existing from all time, for all time, self-caused. That's a possible perfection. God has als- all possible perfections.
God has perfect existence. Therefore, God exists. The idea of God is the being that has all possible perfections. Existence, existence is a perfection, therefore God has it. If, if you are thinking of a nonexistent God, if you are an atheist, then you are not thinking of God.
You are th- like the geometrician thinking of a four-sided triangle. That's not a triangle. You cannot deny the existence of God according to this proof because whatever you're denying isn't God. If you deny existence of that being, that's no longer God because it lacks a perfection. You are saying the being that has all possible perfections does not have a possible perfection.
That's a contradiction. The only way that you can be consistent, that you can be even talking about the idea, is if you attribute existence to it. Therefore, you cannot logically deny that God exists. This proof has never convinced anyone in history. No one has ever become religious because of this proof.
But the question is, if you think it's wrong, which most people do, where is it wrong? Where is the mistake? Philosophy's wonderful because you can argue against anything. There are no authorities, doesn't matter. Plato said it, doesn't matter.
You can say they're wrong. But you have to have a reason