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A
Welcome to Defenders, the teaching class of Dr. William Lane Craig Today An Excursus on Natural Theology, Part 5. For more resources from Dr. Craig, go to reasonablefaith.org it may seem strange to have begun an excursus on natural theology by arguing that we don't really need arguments for the existence of God in order to believe rationally and even know that God exists. But we've seen that in fact arguments for God's existence are not necessary because God can be known to exist in a properly basic way through the self authenticating witness of the Holy Spirit. But to say that arguments for God's existence are not necessary in order to know that God exists or that the great things of the Gospel are true is not to say that there are not also arguments that are sufficient for the knowledge of God. And in fact, I would agree with Alvin Plantinga that even though belief in God and the great truths of the Gospel are properly basic, still there are arguments and evidences that are sufficient to warrant belief in the existence of God and in the great truths of the Gospel. And so today we want to begin to look at some of these arguments for God's existence. The first argument is the argument from Contingency and we have an outline for this for you. If you don't have one, raise your hand and Marian will get it to you. Sometimes this is called the Leibnizian Cosmological argument. I discuss this argument in this book on guard. And then also in a deeper way in the book Reasonable Faith and and we'll be looking this morning at the version as it's laid out in En garde. I have always been impressed by the mystery of the existence of the universe. I remember as a boy looking up at the stars at night and wondering where did all of this come from? It just seemed to me that there had to be an explanation for why all of this exists. Well, little did I realize that my boyhood question as well as its answer had been reflected upon by philosophers for centuries, millennia even. For example, Gottfried Wilhelm Leibniz, who was the co discoverer of the calculus, a polymath of tremendous genius, one of the great geniuses of 18th century Europe, argued that in his words, the first question which should rightly be asked is why is there something rather than nothing, that is to say, why does anything at all exist? Leibniz believed that this is the most basic question that anyone can ask. And like me, Leibniz came to the conclusion that that the answer is to be found not in the universe of created things, but Rather in a transcendent cause of the universe in God. God, he said, exists necessarily and is the explanation for why anything else exists. Now, one of my friends has said to me that it is a shame that I began the book en garde with this Leibnizian argument, because it is an argument that is very philosophical and metaphysical and which the layperson finds, I think, very difficult to grasp. So that right at the beginning of the book, this hurdle is placed in his path, whereas it would have been perhaps better to have begun with easier to grasp arguments for God's existence. But I must say I agree with what Leibniz said, that logically, this is the very first question which ought to be asked before we ask why is the universe fine tuned for our existence? Or why did the universe begin to exist? The most fundamental question is why is there anything at all? So this is clearly the beginning point. Two centuries after Leibniz, Martin Heidegger, who was a very famous German 20th century metaphysician, wrote this. Why are there beings rather than nothing? That is the question. Clearly it is no ordinary question, why are there beings? Why is there anything at all rather than nothing? Obviously, says Heidegger, this is the first of all questions. So that is where we will begin in our survey of arguments for God's existence, with this most fundamental question of all, why does anything at all exist? Now we can put Leibniz's argument in the form of a very simple series of premises which are on your outline. 1. Every existing thing has an explanation of its existence, either in the necessity of its own nature or in an external cause. Two, if the universe has an explanation of its existence and that explanation is God. Three, the universe is an existing thing from which it follows logically. Therefore, the explanation of the existence of the universe is God. Now this is a logically airtight argument. That is to say, if the three premises are true, then the conclusion follows necessarily. It doesn't matter if you don't like the conclusion. It doesn't matter if you have other objections to God's existence. If you think that those premises are true, then you've got to accept the truth of the conclusion as well. So anyone who wants to reject the conclusion has got to say that at least one of those three premises is false. But which one will he reject? Clearly, premise three is undeniable for any sincere seeker after truth. Obviously the universe exists and therefore the skeptic is going to have to deny either premise one or premise two. So the whole question with regard to this argument comes down to this Are these two premises more plausible than not? Are they more plausibly true or are they more plausibly false? Well, let's look at each one of them in turn. First, every existing thing has an explanation of its existence, either in the necessity of its own nature or in an external cause. Now you notice that Leibniz makes a distinction here between two types of being. The first type is, is things that exist necessarily by a necessity of their own nature, a necessary being. This is the idea of a being which cannot fail to exist. It is something the existence non existence of which is impossible. Now, what would be an example of a necessary being? Well, very many mathematicians think that mathematical entities are necessary in this way. Things like numbers, sets, propositions, things of that sort. Even those who are anti realists about these, who don't think that mathematical objects really exist, nevertheless recognize that if they do exist, they exist necessarily. If the number one exists in any possible world, then than it actually exists. It would be impossible for the number one, for example, to just contingently exist, to exist in this world, but not in some other possible world. So even those who don't believe in the existence of mathematical entities like numbers and sets and geometrical figures, still would recognize that it belongs to the nature of these things to exist by necessity, if they exist at all, they exist necessarily. So these kinds of things are not caused to exist by something else. They simply exist by a necessity of their own nature, and it is impossible for them to fail to exist. Now the other type of thing would be things that exist contingently. That is to say, they are contingent beings. Contingent beings are things that exist, but they don't have to exist. It's possible for them to fail to exist. They exist, but their existence isn't necessary. They could have failed to exist. And this is the case with the world of objects around us, things like people and chairs and places, planets and galaxies and so forth. These things exist, but they're not necessary in their being. We can imagine a possible world in which any or all of those things failed to exist. So these kinds of things, if they exist, have explanations outside of themselves for why they exist. They don't exist by a necessity of their own nature. So if, for example, a unicorn exists in this world, there must be some explanation for why it exists rather than not exist. There are lots of possible worlds in which there are no unicorns like the actual world. So if a unicorn does exist, there needs to be some sort of explanation that's apart from the nature of a unicorn. That would explain why. Why the unicorn actually exists rather than is a mere possibility. So when Leibniz says that everything that exists has an explanation of its existence, that explanation could be one of two sorts. The explanation could be that it exists by a necessity of its own nature, that it's a necessary being, or the explanation could be that it's a contingent being that has a cause outside of itself that produces it in being. So if God exists, God is a being that would exist by a necessity of his own nature. It's impossible for God to be caused by anything else. If God were to be caused by something else, then there would be something greater than God and therefore he wouldn't be God. So by the very concept of God, God cannot be something that would be caused to exist by something else. If there is a God, then he would exist necessarily. So Leibniz's argument is driving us toward a very powerful concept of God, namely the idea of a metaphysically necessary being. A being that exists by a necessity of its own nature, not merely a contingent being that happens to exist, but a necessarily existent being. Now with that clarification of premise one, let me ask if there are any questions of a comprehension nature, because as I say, this is the stumbling block at which many laypeople find themselves unable to go further with this argument. They we have to have a clear grasp of the distinction between necessity and contingency in order to go further. So is there any type of, any understanding type of question at this point? Yes. Way in the back, yes. Dr. Craig, just to clarify, so a contingent being would be, I guess, require a necessary being? Well, that will be the argument, yes. A contingent being requires some sort of cause or explanation outside of itself. And ultimately this is going to have to be grounded by a metaphysically necessary being. That's right. You're seeing, you're already seeing the implication of Leibniz's argument, right? Yes. Over here.
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B
Could you explain further more necessary being philosophy? Because obviously the concept of God is huge and hardly comprehensible. Same thing as much math like numbers or time. Do you have something else to relate
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A
that to that will make it more understandable? I don't. The difficulty here is that at least on a Christian view of things, everything physical, everything in the space time, universe, is created by God, is therefore contingent. So one really has to cast about to find non theological examples of necessary beings. And the only place that you can really find these would be in these so called abstract objects, things that are not concrete, made out of matter and energy, existing in space and time, things like mathematical objects, propositions, properties, possible worlds. These are called abstract objects. And I think that the example of mathematics is the clearest. Most of us in math class have thought about whether or not numbers exist or is there a perfect circle? We all know there's no perfect circle in the physical world. So are all these approximations to some sort of abstract perfect circle? Does that thing sort of exist as an abstract object? If it does, it would exist necessarily. It would be impossible to say that there just happens to exist a perfect circle in this world, but it doesn't exist in these other worlds. So mathematical objects for me is the most accessible example of something that exists necessarily if it exists. And so if you want some explanation beyond that, all I can do is say, ask a question and I'll try to respond to it. Is there something that is unclear about the idea of a being whose non existence is impossible?
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C
Dr. Bob Bill, I struggled for a long time with this concept of a necessary being. And I finally arrived at something that at least has helped me and maybe it'll help other people. There is an infinite number of things that could happen to keep me from existing. So I am not a necessary being. There is nothing that could have happened to keep God from existing. And why is this? Well, in my mind, and maybe it's a little too narrow, I've distilled it down to the fact that he has no beginning. Anything that has no beginning is necessary because nothing could have happened to prevent his existence. And there's only two things that I can think of that have no beginning, and that's God. And that is, and we won't get into time but his time. I think they're probably different times because both of those entities had no beginning. Now, the second thing about abstract numbers and all, to me, those are concepts. And a concept can only exist if there is an intelligence. If there is no intelligence or comprehension, there's no number seven, there's no square root of this, that and the other. But since God is necessary, he is the intelligence. And so they are necessary too, because he's here to have them as a concept.
- [16:24]
A
All right, now let me address the second concern. First, do you remember in our discussion of the attributes of God, we talked about divine aseity or self existence, and the challenge posed to that by Platonism, which is the philosophy that there are these sort of abstract, necessarily existing, uncreated entities like numbers and sets and geometrical shapes and so forth. And one of the Christian responses, indeed the mainstream Christian response to this challenge is exactly what you Said namely that these are divine concepts, so they don't really exist independently of God. They are ideas or concepts in the mind God. So I think that's a defensible perspective. But as I emphasized in appealing to this example, even people who are conceptualists would recognize that if there were these sort of Platonic entities like numbers and sets and so forth, they would be necessary beings. They would be things that exist by a necessity of their own nature. But he thinks there aren't those sort of things. He thinks instead, these are concepts in God's mind. There aren't really abstract objects. So while I agree with you, or tend to agree with you, that these things don't have any sort of independent existence of God, I don't think that robs the illustration of its power because it is the best example of a necessary being. That's not God, if the Platonist is right, if it exists. Now, I liked very much, Bob, what you said in your first question about nothing could prevent God from existing, where, as with contingent beings, they could be prevented in their existence. There are other possible worlds where these things never happen or never come to be. But I want to resist, however, then your explanation of why God can't be prevented from existing and why other things can. You found that in the fact of a temporal beginning, and I don't think that's right. Indeed, Leibniz emphasizes that you cannot evade his argument by saying the universe is eternal, whereas if you gave your explanation, you could evade evade his argument that way. But Leibniz says even if the universe has existed from eternity, it's still possible for it not to have existed. It's logically possible that there be no universe at all, or that there be a universe with a beginning instead of an eternal universe. So even saying that the universe is beginningless and eternal in the past doesn't answer Leibniz's question why is there something rather than nothing? So while I like what you said about God's necessity meaning or entailing that nothing can prevent his existence, I wouldn't find that in his being beginningless, because that will allow. Well, I think it's incorrect and it would also allow the atheist away out of this argument. Okay, Brad, just a quick understanding question. Right. It seems like what we're saying is if there is a God as we've defined God, he is a necessary being, but it requires us to say our definition of God is this, and therefore he would be a necessary being. It's not a proof that God. Am I understanding that correctly? Well, sort of wait until we get to premise two where it says if the universe has an explanation, that explanation is God. That's where God will get pulled into the argument, but not in premise one. Premise one is just a principle that things that exist have explanations for why they exist. And those explanations can either be in some external cause or that they exist by a necessity of their own nature. And in philosophical literature and in Leibniz own writing, this was called the principle of sufficient reason. Now Leibniz stated a very radical version of this principle. The version that I have here is a quite modest version of the principle that I think is very plausible. As I'll say it requires simply that any existing thing has an explanation for why it exists rather than not. But we'll talk then about whether or not premise 2 is true and we're justified in calling this being God.
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B
Yes, perhaps this is similar to Bob's comments, but if it seems to me that only God is existence by necessity because even time began to exist. Also, when you think of numbers, you're looking at numbers are a way to consider objects, are they not? It's a concept. But I don't know how you could have even a concept that is separated from God, because I can't even imagine anything that can exist that has an origin of God.
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A
You mean apart from God?
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B
Apart from God.
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A
So yes, again I want to refer back to our discussion of divine aseity when we talked about the attributes of God and where I argued precisely this point that everything that exists other than God is contingent and dependent upon God. But what that just means is that I'm not a Platonist, okay, but many mathematicians are Platonists. They don't ground these objects in God as his concepts. They think that the number one and the set of natural numbers and the perfect circle, other geometrical shapes, they think these things are real objects that actually exist, they're abstract objects. So I'm saying that on Platonism we have an illustration of a non theological necessary being. So I'm trying to find something here to illustrate for lay folks what a necessary being is that doesn't appeal to God. But to take the best example I can come up with is if you're a Platonist, you're loaded with these things.
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B
But even on that score, not to belittle, belabor the point, but you have to have a mind to conceive of the, I mean of the contingent or the necessity. So in a way, oh, you know, Platon even, you know, was, it's a concept of a mind. But Then does the mind not have.
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A
Okay, well now this is so interesting, Cindy.
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B
So you have to be a mind.
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A
Plato had a concept that he called the demiurge. And this is sort of God with a small G. And he is the creator of the physical world. And what Plato says is that these objects, these abstract objects or forms, are the most real things. They exist independently of anything else. And God, little G, looks to the forms and then he fashions the physical world on their model. So that the perfect circle is the model for these approximations that God makes. Or these numbers are the ideal entities. When God makes three things, say than there are one, two and three in the realm of the forms. So yeah, the concrete world on Plato's view is due to the action of this demiurge. But he isn't responsible for this realm of forms or abstract objects. They exist quite independently of him. Now, as you rightly point out, and Bob reminds us, this is utterly incompatible, I think, with Christian theism or Jewish Christian theism. So the church fathers rejected Platonism and they tended to put these things into the mind of God. These are God's ideas. They internalized Plato's realm of the forms into the mind of God. So when I appeal to this illustration, I'm appealing to for the most part non theistic mathematicians and philosophers who still endorse Platonism. Sadly, the truth is that there are good, many Christian philosophers who endorse Platonism as well. I'm thinking of people like Peter Van Inwagen and Keith Yandel who are Platonists. I am baffled by that. But there are Platonists today who think that these things are necessarily existing beings.
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B
Are these not then just a character of God, these concepts? So in essence they're saying they believe in this concept, but they're not giving that as part of God's character.
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A
Well, they don't think they're concepts. They think they're real objects. They're as real as this chair or you. I mean, in some ways they're more real in one sense in that they exist necessarily, whereas the chair and you are just contingent. Okay, Bruce.
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C
I think what Cindy was trying to
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go is one step further, and I
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C
would agree is that you can't objectify
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these things without a mind.
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C
You can't have a concept of oneness
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A
and numbers and abstraction unless there's a mind which presupposes you can. You could understand such a thing. So. All right. Well again now we're reverting to our earlier discussion about divine aseity. And I don't want to rehearse that again here, because all I'm trying to do is illustrate the idea for you of a necessary being. Now, I agree with you that Platonism is false. So we're on board with each other, right? But do we understand the idea of a being that exists by a necessity of its own nature, a being that cannot fail to exist? If you get that idea, then fine, that's all we want to establish. And then how that's distinct from a contingent being which happens to exist but could fail to exist if things had gone otherwise and therefore has some cause outside of itself. Now, I think Taewon had a comment she wanted to make.
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B
Dr. Craig. Can we use a substitute description for necessary being as a set of divine concept? Because the John 1:1 says in the beginning with the Word, and the Word is just divine concept. As we, the being has ability to think on concept, there may be a law that the concept can, can, can come together and become a set. And that said, we call it God.
- [28:22]
A
Well, I'll go with you part way on that, Taewon. In the beginning was the Word or the Logos. This is who Jesus Christ is said to be. He is the incarnate Logos. And as I indicated in response to Bruce and Cindy and Bob, the church fathers located these abstract objects in the Logos. The Logos is the mind of God, and these things are concepts in the mind of God. But all of these questions concern the previous lesson that we've already finished about divine self existence or satiety. All we're talking about here now is is it true that everything that exists has an explanation of its existence? And there are two types of explanation? And I think you get that. You just want to talk about this other thing. Okay, one more question.
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D
I guess maybe we're looking for more literature on this.
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A
Oh, that's easy to get.
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D
So, but yeah, I asked my friend this question, why is there something rather than nothing? And this probably was a month ago over lunch and stuff, and he walked away asking to think about it. So about two weeks ago I again asked him, so did you come to a conclusion? He says, no, he's still looking. And now I'm kind of looking too to help him out. And there's some articles out there, but they're very complex. So I don't know where else can we turn on this particular question and this argument?
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A
Well, have you read the treatment of this argument, for example, in reasonable faith yet?
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D
I have not.
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A
Okay, that's a place to begin. And there is the. There are footnotes that you can follow. To read further literature on Leibniz's argument, you can go back and read Leibniz himself.
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D
Is there a chapter that I should look into or what?
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A
Pardon me?
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D
A particular chapter in there that I should.
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A
Yes, it's chapter three in the book. Okay, so that's a place to look. And as I say, there are citations to further literature and bibliography there. Alright, well now, what reason might be offered for thinking that premise one is true? Why should we think think this is true? Well, I think when you reflect on it, there's a kind of obviousness about the premise. If something exists contingently, like say if there is a unicorn rather than no unicorn, then there needs to be some sort of explanation for why one of those alternatives is actualized rather than the other. Why does the unicorn actually exist rather than not when it's non existence was possible? Richard Taylor, who was a prominent 20th century American philosopher, gives a wonderful illustration for this. He says, imagine you're walking through the woods and you suddenly come upon a translucent ball lying on the forest floor. He said, you would naturally wonder why it exists. How did it come to be there? And if your hiking buddy said to you, oh, forget about it, it just exists. Inexplicably there is no explanation of its existence. Taylor says, you wouldn't accept that. You'd think that the guy was either just joking or wanted you to just keep moving. But it's obvious that there would be some kind of an explanation for why that ball exists. Now notice that merely increasing the size of the ball, say 20, until it's the size of an automobile, does nothing to explain its existence. Or making it even bigger to the size of a house. Same problem. Suppose it's the size of a planet. Same problem. Suppose it's the size of a galaxy. Same problem. Suppose it's the size of the entire universe. Same problem. Merely increasing the size of the object does nothing to provide an explanation for its existence. So if you have the sense that finding a ball in the woods requires an explanation for its existence, that I think will lead inevitably to saying that bigger and bigger and bigger objects, even the universe itself, will have to have an explanation of its existence. Because merely increasing the size of the ball does nothing to either provide or remove the need for an explanation of its existence. Now with that, we will close today and then I will take up next time some atheist responses to premise one to try to exempt the universe from this principle. So we will see you next week.
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D
The copyright for the content of this
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recording is held by Dr. William Lane Craig. For more, go to reasonablefaith.org.