Video Transcript: Lesson 10

Greetings. We're back. We're going to resume our study, and we're to take up  today the some good samples of proofs of the existence of God that have been  given over the centuries, particularly by Christian thinkers. There are also  Jewish thinkers who have given proofs of existence of God. There are Muslim  thinkers who have done so, but it's mainly the Christian tradition that has been  rife with them. Augustine had three proofs of God's existence. Saint Anselm  famously gave one that people still debate today. But the high point especially  up through the Middle Ages, were the five proofs of St Thomas Aquinas. St  Thomas died around 1278 I've seen 1277 in print. I've seen 1278 somewhere  around there, and he gave five proofs. And today we're going to look at his third  proof. And it's, I have it already written on the board. So I'm going to go over  here now and go through the premises with you. In the logical proof, we have  premises, and then we draw a conclusion. The first premise of this argument is  some things are such that they can exist or not that, of course, the truth of  observation, you just look around the world, it's hard to see anything that you  think isn't like that. Certainly anything we can think of seems to be of such  character that either it could exist or not, it could be destroyed. So he All he says is, some things are like this, where the word some in logic means at least one.  There's at least one thing that's such that it can exist or not. And we, in fact,  know that just about everything we can see and think of is like that. But now  premise two might need some explaining for you here. Thomas says, whatever  can fail to exist must, at some time do so. And you might wonder why in the  world, he thinks that. Notice that this premise is much more strongly worded  than the first one. The first is simply an observation of a matter of fact, but the  second says, whatever can possibly not exist must, at some time, not exist. It's  not a possibility, merely a possibility. If it's possible, it must happen. Why would  he think that that takes little explaining? Let's see if I can make this clear, here is thing that can or not exist. Here's our sample thing. Now, if this is really  something which can possibly not exist, there cannot be internal to it any reason that would prevent it from going out of existence. It has to be the kind of thing  which doesn't contain within itself anything that would allow it to cease to exist.  But it's also the case that there can't be any reason outside of it that prevents it  from failing to exist. If either one of those were true, it would not be the kind of  thing that can possibly not exist. So for anything to be this kind of thing, there  can't be a reason external to it or internal to it that would prevent it from failing to exist. And you say, Okay, so, alright, but this brings us to an assumption behind  the argument. That assumption is called the principle of sufficient reason.  Thomas and almost every philosopher prior to him, and for oh, a good 500 years after him, held that this is an axiom that is true, the principle sufficient reason  that goes like this for everything there must be a cause or explanation. I'll pause  there and let you think about that minute. For everything there must be a cause  or an explanation. That means that this thing could not continue to exist unless 

there were some cause or explanation. I've used the term reason to combine  cause and explanation, unless there were some reason for it. So what we have  is this, the following, a thing is. And the kind of things spoken up in premise one, it's something that can exist or not exist only if there is no cause or explanation  for its continuing to exist and never cease. But we've already said if, if a thing is  this kind of thing, it really can fail to exist. There's no reason within it, no reason  outside of it that would prevent that, therefore it can't happen. So premise two is  a necessary truth, if and only if the principle of sufficient reason is a necessary  truth. Premise two, assumes that for everything there must be a cause or  explanation. Now you might want to say, feel like saying to me, Well, wait a  minute, if you say for everything there's a cause or explanation, then that would  include God, wouldn't it? And he wouldn't want to say that. He wouldn't say  there's a cause for God, and that's right, but there is an explanation, he thinks.  And the explanation is simply that God's being is such that it can't fail to exist.  The explanation is God is self existent. God is God. So while the being of God  has no cause, it has an explanation. God contains the explanation within  himself, where you say, Okay, what is that explanation? Exactly, why? Why is  God like that? And Thomas answer is that explanation. We know is known by  God, because God's omniscient. Knows everything. We don't know what that is,  but God knows. So we know there is an explanation, even though there's no  cause, because it's known to God, because everything is, I don't know whether  you feel at that point as though you're being tricked. I hope God, he's quite  sincere about this. This is the reflection of a first rate philosopher on his faith in  relation to the principles of logic and the principle of sufficient reason. Anyway, I  hope I've made clear here that there are some things that can fail to exist.  Whatever is like that would have to fail to exist because there would be no  cause or explanation for it to continue forever. And then we come to premise  three, if everything were like that, if all things could fail to exist, then at some  time, everything would fail to exist, and there would now be nothing. And of  course, he goes on, it's absurd that there's now nothing that's false. Therefore  it's false that all things can fail to exist, therefore there's something that can't fail  to exist. And then he ends, et Haq di chimus es Deus, and this we say, is God.  So what he's done is prove that there has he thinks that there has to be  something that can't fail to exist, and that something is the something we call  God. This does not attempt to prove anything else about God other than his self  existence. That's all it tries to do. It doesn't try to show that God is in Trinity. It  doesn't try to show that God cares about human beings, that He sent His Son  into the world to save the rescue the world from sin and death. None of that. We  don't get that out of this argument. All we get is there's something that can't fail  to exist and that we call God. And he has other arguments for other  characteristics of God, and He concludes them all the same way. He had five  proofs in total, and every one of them ends. And this, we say, is God. I can't ask 

you what you think of this argument. If you were here present, I would, and we'd  have a little chat about this. It's an impressive attempt, but I don't think that it  succeeds. Let me tell you why. First of all, some philosophers since the 18th  century, have denied the law, the principle of sufficient reason. They've said they didn't see any reason to think that there had to be a cause or explanation for  anything, for everything. And how would you know that that itself is a necessary  truth? Notice, the principle says, for everything there must be, not there is. There has to be a cause or explanation. How would you know that? So some people  have called this into question. Philosophers by Thomas time all had held this so  he didn't think it was a problem. But from his time to ours, philosophers are  divided. Some still accept the principle, some reject it. So. That's one weakness, but by the time we get to premise three, we have something that's not just the  weakness, but a well known logical fallacy in logic. It's called the fallacy of  composition, and what it says is the fallacy says you can't just say that, because all the parts of something have certain characteristics the whole thing has.  Sometimes that's true and sometimes it isn't. Here's an example of when it isn't.  Suppose every component of a certain machine was a light part weighed an  ounce or less, all the parts would be light. Would the whole machine be light?  Not if it had a million parts, each part would have that characteristic, but the  whole would not. Now, as I said, sometimes it's correct to say of something, that  if all the parts have a certain characteristic, the whole has it. But you because  there are many times it's not true. You can't just say that because these parts  have the characteristic the whole does. That's not sufficient. That's just a fallacy.  You would have to give special reasons for thinking that. In this case, that  characteristic carries over from the parts to the whole. And he doesn't have that  here. What he says is, if everything were the kind of thing that could fail to exist,  then the entirety of all things would have the property of being able to fail to  exist, and would at some time fail to exist. So it's a clear cut case of the fallacy  of composition. It does not follow that if each and every thing could fail to exist,  they'd all do it at the same time. Why couldn't things, some things come into  existence, cause others, and then fail to exist, while the others go on and cause  others and then they fail to exist, so that every at all times there would always  be something, although things were failing to exist all the time as well. There's  no reason he gives us that rescues this as one of the unusual circumstances in  which all the parts of something having a characteristic does mean that the  whole has the same characteristic, but that's what three hinges on. It hinges on  accepting this premise, which embodies a logical fallacy. That's his reason,  though, for saying that if everything could fail. If everything were like the things  in premise one, if everything could fail to exist, there'd be nothing. And of  course, premise four, it's absurd that there's now nothing. You and I are here.  The board is here, the argument, the books, the room. It's absurd that there's  now nothing, from which it follows that not all things cannot exist. That form, that

logical move, is a step called modus tollens and logic, and it's perfectly valid one to make. If three and four were both true, they would require that it's false, that  all things are such, that they can fail to exist, and that would entail that there is  something that cannot not exist. It entails that there's at least one thing  remember the meaning of some at least one. It would show us, even if it were  correct, even if there were no other problems with this argument, it would show  us that there is at least one thing that cannot fail to exist. Why couldn't there be  dozens or billions? It doesn't show us that there's only one thing that cannot fail  to exist. And it's that latter belief that that is equivalent to God. For a Christian,  God is the only thing that cannot fail to exist. God is self existent. All else is his  creation. So I'm afraid that for several good, very good reasons, this attempt at  proof fails. It fails because the principle of such as of sufficient reason may be in  doubt that could be denied reasonably by someone, and then premise two  wouldn't, would would not be accepted by them. It fails because premise three  commits a fallacy, and it fails because the conclusion is taken in the sense that  there is only one thing, and that we call God not and them, we call gods  because it implies some undisclosed number of things could be such that they  can't fail to exist. So for as far as the premises go, it proves less than it should.  As far as the conclusion goes, it proves more than it should, if it proves  anything, and I think it doesn't. This, however, is a famous argument for the  existence of God. It's still examined and studied, and it still has people that try to fix it up and defend it. They try to reword some of the premises to avoid these,  these objections. I know one professor who said, I don't need to assume the  principle of sufficient reason. I don't have to assume that for everything there  must be a cause or explanation. All I would have to do is assume that it is  possible that for everything there is a cause or explanation, so I don't have to  defend the principles, the necessary truth, and this whole thing will still work.  Then that's an example of an attempt to defend it. Of course, someone, many of you would probably never thought about the principles sufficient reason before.  Why would you it doesn't come up over t but it's a serious issue still in  philosophy, and a lot of people are inclined to say, Yeah, but I think it's right for  everything, there would have to be a causal explanation. If you do believe that,  though, you have to defend it in some way. You would have to claim that it's self  evident, or you would have to give something like a reason to believe it. And one of the reasons a lot of people are inclined to say they believe it is they believe in  God. You see, they believe that, in fact, there is a causal explanation for  everything other than God, and the causal explanation is God, and that would  be one way to go. But he couldn't take that view. See, because if he said the  principle is true because God exists, then the whole argument would beg the  question, he'd be premising God and concluding God. And that makes the  argument circular and worthless. That's that ends my treatment of this proof.  Now, that tradition of offering proofs for the existence of God, as I already said, 

started long before Thomas, and it hasn't stopped.