Argument from Contingency

August 05, 2007     Time: 00:43:53

Today we are going to turn to a new topic: arguments for the existence of God. We’ve been talking the last several weeks about the attributes of God, the nature of God. The apologetic question that naturally arises at this point is: How do we know that God exists? Does God exist? Are there good reasons to believe God exists? That is the subject that we want to consider now before going on in our further survey of Christian doctrine.

When I speak of arguments for the existence of God, it is very important that we understand that I am not talking about quarreling with an unbeliever or fighting with an unbeliever. I simply mean giving reasons for why we believe that God exists. This should be done in a spirit of good will and Christian charity.

In order to provide arguments for the existence of God, we first need to understand what the conditions for a good argument are. Basically there are three conditions for what makes a good argument.

1. The argument must be logically valid. That is to say, the conclusion must follow from the premises according to the rules of logic. So, for example, we might reason: If all men are mortal, and Socrates is a man, then Socrates is mortal. That would be a valid argument. That is a logically valid inference. I can simply assure you that all of the arguments that I am going to be sharing with you during the next several weeks are logically valid. They all follow the rules of logic. So there will be no logical fallacies in the arguments that I share. If you master these arguments, you can be certain the arguments you are presenting will meet the first condition of being a good argument – that it is logically valid.

2. The argument must have true premises. It doesn’t do any good to have logically valid arguments if the premises of the argument are false. The premises of the argument are the various steps of the argument from which the conclusion is inferred using the rules of logic. This is the most important question with respect to building a good argument – to be sure that your premises are true. So given that the logic of my arguments that I am going to present is valid, the real question is: are the premises true? This is where the disagreement with the unbeliever will come. It will be on the truth of the premises. This is important because it will enable you to avoid a lot of intellectual smoke screens and red herrings that the unbeliever might throw in your path because he doesn’t like the conclusion that your argument is leading to. You can keep focusing him back on the premises of your argument. Say, “My argument is logically valid, and I believe the premises are true. Therefore you have got to either show me an error in my logic or you’ve got to show me which of my premises are not true. Otherwise, the conclusion follows from my argument.” So it must have true premises.

Even that isn’t entirely enough for a good argument. There is a third condition and that is:

3. The premises of the argument must be more plausible than their negations. That is to say, it is not enough for the premises to be true. They need to be plausibly true. That is to say, we have to have some reason for thinking that these premises are true. They need to be credible in some way. There needs to be perhaps evidence for these premises, or the premises need to be obvious or in some way more plausible than their negations. By their negations I simply mean the contradictory of that statement. If you just put “not” in the statement you will obtain its negation or its contradictory.

So our goal is to present arguments for the conclusion that God exists which are logically valid arguments based on true premises which are more plausible than their negations. If we have done that then we will have provided a good argument for the existence of God.[1]

This is important to understand because when many people object to providing a proof for the existence of God by saying, “You can’t prove that God exists” they are using the word “proof” in the sense of a mathematical demonstration where you will have a 100% certainty of the conclusion and a 100% certainty of the premises of the argument. That is simply an unrealistic standard. In order for an argument to be a good argument the premises do not need to be known with 100% certainty. The conclusion doesn’t have to be known with 100% certainty. The premises simply have to be known to be more plausibly true than their negations. If that is the case then you will have established your conclusion as a plausible conclusion that a rational thinking person ought to believe. So the argument doesn’t have to lead to certainty. It simply has to make the conclusion more plausible than its opposite, and you will do that if you give an argument that is logically valid with true premises that are more plausible than their negations.

So I think personally it is better to avoid all together this word “proof” when people talk about whether you can provide proof for God’s existence. Because that raises a standard of certainty in their minds that is totally unrealistic. If that is what you mean by prove then we can hardly prove anything. There is virtually nothing that we know in life that can be proved with 100% certainty. So I prefer to simply talk about good arguments for God’s existence or, to use another word, good reasons to think that God exists. That is all you are claiming when you talk to the unbeliever. So you can just leave aside this emotionally loaded word “proof” and simply talk to your unbelieving friend about good reasons to think that God exists or that you think there is good arguments for God’s existence that make it more plausible than not that God exists. Then you will have fulfilled your apologetic task.

Plausibility is to a large extent a person-relative notion. Some things may seem plausible to me but they might not seem plausible to you. Since all of us come to the evidence with a unique background and biases and prejudices that we bring with us, certain things will appear plausible to some people but will appear implausible to other people. So in that sense what constitutes a plausible argument will be to a degree person-relative. But obviously we will try to present arguments that the general majority of people will find are based on plausible premises. Arguments that won’t be peculiar just to yourself, but would have a broad appeal to most right-thinking people. That is what we would attempt to do in terms of presenting plausible arguments.

Because plausibility is person-relative, this means that sometimes people, because they don’t like the conclusion that the argument is leading to, will simply deny one of the premises of the argument instead. They will simply say, “That is not a plausible premise. I don’t think that premise is true.” You might think, “Well, then your argument has failed.” But that is not at all the case. For any argument you can avoid its conclusion as long as you are willing to pay the price of denying the truth of one of its premises. The goal of presenting an argument is to try to make that price as high as possible. You want to make the price of denying the conclusion that God exists as high as possible by presenting arguments that are based on very plausible premises. So in order to avoid your conclusion the unbeliever will have to pay the price of adopting a very implausible position with respect to one of the premises that you are offering. So don’t be discouraged if the unbeliever chooses rather than to believe in God to believe in some wildly implausible option instead. That actually is success in your argument if you have been able to force him into adopting some wildly implausible view rather than accept what he really knows to be true just because he dislikes the conclusion that he sees that it is leading to.[2]

This, I think, helps to highlight a very important feature of arguments for God’s existence because, you see, the conclusion that God exists has such tremendous personal significance, such existential importance, that issues of the heart take on a paramount importance in this area. I am reminded here of a distinction which is drawn by the British theologian J. I. Packer between two types of people who have an interest in God. One type of person, he says, is like a traveler along the road of life who is down there on the dusty road making his way along the journey and trying to reach his destination. The other type of person, he says, is like the people who sit on the balconies of the houses lining the road. He says the people sitting on the balconies can watch the travelers going along the road before them and they can take quite an interest in what travelers on the road are talking about. They can converse with the travelers as they go. They can share with one another, argue about the things that the travelers are concerned about. But Packer points out that there is a profound difference between the balconeers and the travelers; namely, the travelers are the ones who are actually making the journey whereas for the balconeers the interest is purely theoretical. They are not really going anywhere. I find in exactly the same way that there are two types of people with respect to an interest in God. There are travelers and there are balconeers. The traveler is the person who is struggling along the road of life and is really interested in finding out whether God exists. The balconeer is someone who just sits back and considers this issue as a theoretical question and isn’t existentially involved in it. These two types of people will approach the arguments for the existence of God with completely different attitudes. The traveler who is really trying to find out whether God exists will approach the question of God’s existence with a deep humility. He will be eager to find evidences of God’s being. He is searching for God. He wants to discover whether God exists or not. He is like a person who is looking for a lost loved one and who will be eager to find any evidence of that loved one’s presence. That is not to say that he is going to become gullible and just jump at straws. But it is to say that the traveler’s approach to the existence of God will involve an openness and a sincerity to finding him that balconeers often do not. Balconeers instead will often be indifferent or even hostile to God. They don’t really want to find God at the end of their search. For example, here is what the philosopher Thomas Nagel has to say,

I want atheism to be true and am made uneasy by the fact that some of the most intelligent and well-informed people I know are religious believers. It isn’t just that I don’t believe in God and, naturally, hope that I’m right in my belief. It’s that I hope there is no God! I don’t want there to be a God; I don’t want a universe like that.

This kind of a person will approach the arguments for God’s existence with a totally different attitude from that of a traveler. Rather than looking for God, he will be looking for loopholes. Rather than accept the argument’s conclusion, he will deny at any cost one of the premises rather than deny the conclusion, no matter how implausible the denial of that premise might be. I find that each one of us has inside of us a kind of skeptical dial that we can turn way up high when it comes to conclusions that we don’t like, and we dial it way down low when it comes to our own philosophy and our own views. And the hypocrisy of many balconeers is that when it comes to God’s existence they dial that skeptical dial up to a degree that would be totally unacceptable to them in any other area of life.[3] If they were to apply the same sort of skepticism to ordinary life that they apply to arguments for the existence of God, they would scarcely to be able to function. For example, I am astonished at the number of atheists that I have read and know who, rather than admit that God created the universe, will instead assert that the universe just popped into being uncaused out of absolute nothingness. Now they would never adopt that conclusion in any other area of their life. For example, if they woke up one morning and found a car was sitting in their driveway that hadn’t been there the night before. Or if ten thousand dollars were found in the bank manager’s briefcase as he left the bank, no one would accept a conclusion, “Oh, well, it just popped into being uncaused out of nothing.” Yet, when it comes to the existence of God, this is the premise that they are willing to accept, rather than embrace the existence of God.

For balconeers, arguments for God’s existence are at best intellectual games. They don’t really hope to or expect to find God at the end of the argument. But obviously, if God exists then we can’t play intellectual games with God. Rather, we have to approach God with a sincerity and a humility and a deep reverence, I think. If we are seekers after truth, if we are travelers along life’s way, then we will approach the arguments for God’s existence sympathetically. Therefore, I think that the so-called skeptical inquirer is really an oxymoron. Someone who is a genuine inquirer is not skeptical at all. He wants to find the conclusion and find the truth. So when I hear someone who says they are a skeptic or a skeptical inquirer, I think that tells me already something about where their heart is. If we are really to hope to find God then we must approach these questions with an openness and a sincerity to really finding God at the end of the argument and not try to deny at any cost his existence.

So plausibility raises these issues of the heart. Sometimes by presenting an argument for God’s existence, you will actually expose the heart condition of the person with whom you are talking because you will see that they will, rather than admit the conclusion of the argument, adopt positions that are totally implausible. They will pay that price rather than believe in God. If that is the case then you have done your job as a Christian apologist, as a defender of the faith. You have shown that person not only the cost that it is going to be to them intellectually to deny God’s existence, but you also expose the condition of their heart as someone who is not really open and ready for God at all.

Those are the conditions for a good argument for God’s existence or for any argument.

Now, are their arguments for God’s existence that are good arguments? Well, I think there are and I’ve laid some of these out in a couple of places. One is in my little book God, Are You There? Published by RZIM. If you are interested in following along with these Sunday School lessons, I’d encourage you to take a look at this little book God, Are You There? Published by RZIM. The other book is the book God, A Debate Between a Christian and an Atheist, which I co-authored with Walter Sinnott Armstrong. That will give you not only my presentation of the arguments but it will give you an atheist’s response to these arguments as well. You can weigh for yourself which way the evidence points. So those are two resources if you want to go into more detail on some of these arguments.

The first argument that I would like to consider with you is the argument from contingency. To say that something is contingent means that it is not necessary. It is the opposite of necessity. It means that something is the case but it doesn’t have to be the case. Sometimes contingency is used in the sense of “it depends on something else.” It is not independent. It depends on something else.[4] But in any case if something is contingent then it is not necessary. So this is an argument from contingency.

We can formulate this argument, I think, as follows:

1. Every existing thing has an explanation of its existence. That explanation can be one of two types: either in the necessity of its own nature or else in an external cause.

This is one version of the so-called Principle of Sufficient Reason. Although there are, I think, formulations of this principle that are objectionable and perhaps implausible, it seems to me that this formulation of the Principle of Sufficient Reason is a very plausible formulation of the principle. What it says is that every thing that exists – that is to say, every object or every entity or anything that possesses properties – must have an explanation for why it exists. This explanation can either be in the necessity of its own nature or else in an external cause that brought it into existence.

That means that everything that exists is either one of two types: either it is necessary in its being (it exists by a necessity of its own nature), or it is contingent in its being (in which case it depends upon an external cause).

Let me give some examples.

What would be something that exists by a necessity of its own nature? Well, many mathematicians think that numbers exist in this way. Things like 0, 1, 2, 3, and all of the rest of the natural numbers. By numbers here I don’t mean these marks on the whiteboard, but I mean the numbers themselves. The quantities themselves – 1, 2, and 3. Or many mathematicians think that sets exist, like this set which has one member, namely the number 0: {0}. They would say there are an infinite number of sets. Or mathematical functions like the F(a) is a function. Or geometrical shape like a square or a circle. They would say that these things are things that actually exist. Mathematicians often think that these things are real, and if they exist they don’t have any causes. They are not contingent; there is no cause of the number 3. There isn’t any cause of the set of all space-time points. These simply exist through a necessity of their own nature. Mathematical objects are necessary beings.

By contrast, contingent beings would include things like people, podiums, classrooms, galaxies, planets, mountains. These are contingent in their being. They don’t exist by a necessity of their own nature. Rather, they have external causes which explain why they exist.

So this first premise says that every thing that exists has an explanation of its existence, either in the necessity of its own nature or else in some external cause. It seems to me that that is an eminently plausible premise. This is a premise which underlies all of science. Science has an insatiable thirst for explanation. It always wants to explain why something exists. It doesn’t accept that it is just a brute fact that the thing is just there with no explanation. So this is a principle which underlies all of science. I think it is very plausible in and of itself. Here is an example that is given by the philosopher Richard Taylor. He says imagine you were walking in the woods one day and you came upon a glowing translucent ball lying on the ground. He said wouldn’t you think there was an explanation as to why that translucent ball was lying there? Surely you would. No one would say it is just there and that is all.[5] You would say there is an explanation of why that translucent ball is lying there on the forest floor. Now Taylor says imagine the ball were larger – that it was, say, the size of a building. Wouldn’t you still think that it had an explanation of how it got there? Why it existed? Of course you would. He says now suppose that it is the size of a continent. Wouldn’t you still think it had an explanation? Suppose it were the size of a planet. Wouldn’t you think that there was an explanation for it? Suppose it was the size of the entire universe. Wouldn’t its existence still cry out for explanation? I think we would say intuitively yes it does. In that case it means that even the universe itself would cry out for an explanation of why it exists rather than nothing. So I think that this first premise is an eminently plausible premise; certainly more plausible than its contradictory.

So everything that exists has an explanation for its existence, either in the necessity of its own nature or else in an external cause.

2. If the universe has an explanation of its existence, that explanation is God.

Again, this seems to me to be a very plausible premise. The reason I like this premise is because it is logically equivalent to a premise that atheists themselves often assert. You will often hear atheists assert a similar statement which is logically equivalent to this.

Now what do I mean by logically equivalent? I mean that these two statements always have the same truth value. For example, let’s take the statement “P -> Q.” The arrow (->) is a logical symbol meaning implies. This could also be read “If P then Q where P is a sentence and Q is a sentence.” This is logically equivalent to saying “¬Q implies ¬P” where the crooked sign is the negation sign. So those are really logically equivalent. If P then Q is logically equivalent to saying not-Q implies not-P. In fact, that is exactly what you have here. If we leave P be “the universe has an explanation of its existence” and Q be “the explanation is God” what atheists have always affirmed is this: “If God does not exist (if the explanation of the universe is not God) then the universe has no explanation of its existence.” That is to say, atheists have very often said this: “If God does not exist then the universe has no explanation.” This is what atheists very, very often say. If God does not exist the universe has no explanation. As Bertrand Russel, the great atheist philosopher, put it, “The universe is just there. And that’s all.” There is no explanation.

So atheists often say if God does not exist the universe has no explanation. But, you see, that is logically equivalent to saying, “If the universe has an explanation, then that explanation is God – then God exists.” So this second premise is logically equivalent to a premise that atheists themselves affirm. That is very nice because then that means that you can say, look Mr. Atheist, this is a premise that you yourself have affirmed. This is a premise that many atheists believe because it is the same as this statement “If God does not exist the universe has no explanation.” That would be not-Q (if God does not exist) then not-P (the universe has no explanation). Not-Q implies not-P. That is equivalent to saying “If the universe does have an explanation then God does exist or that explanation is God – its the same thing.”[6] I hope that is clear. That is one of the nice things about the second premise of this argument – it is logically equivalent to an assertion that atheists will very, very often make about the universe; namely, that it has no explanation of its existence in the absence of God.

But taken on its own merits, I think premise (2) is very plausible because consider what the universe is. The universe is all of space and time. As Carl Sagan used to say, “The cosmos is all there is, was, or ever will be.” He was speaking as an atheist. The universe includes all of physical reality – all matter and energy, space and time themselves. So if there is a cause of the universe or if there is an explanation of the universe this has to be something that transcends the universe, that transcends matter and energy, space and time. God is the most plausible candidate for what such a being like that would be. So the premise is very plausible in and of itself. If the universe has an explanation of its existence then that explanation would be a being which exists beyond time and space and is therefore immaterial and timeless. If it is beyond space then it cannot be a material object. So this being would have to be immaterial, right? If it created space it cannot be a material object. But it would also have to be timeless if it created time. So the cause of the universe would have to be an immaterial and timeless being.

There are only two types of things that I can think of that philosophers have ever thought of that could satisfy those types of conditions. One would be abstract objects. Those would be things like numbers. Mathematical objects. Sets. Functions. These abstract mathematical entities are immaterial and they are typically thought to be timeless. The number 1 doesn’t exist somewhere in time or in space. So an abstract object could be timeless and immaterial.

The other thing that would fit this description would be a personal mind. By a mind obviously I don’t mean a physical brain, I mean a self-consciousness or a soul if you will. Such a mind would be immaterial because minds are not made up of matter, and it could be timeless if it exists beyond time and is changeless.

But abstract objects cannot cause anything. Abstract objects do not stand in causal relations. The number 1 doesn’t cause anything. One of the characteristics of abstract objects is that they are causally impotent. They are causally effete. They stand in no causal relations. So that means that the explanation of the existence of the universe must be a transcendent mind. And that is exactly what theists mean by God.

So wholly apart from the fact that the atheist admits the truth of premise (2) by affirming a statement that is logically equivalent to it, premise (2) is very plausible in and of itself because if there is an explanation of the universe it would have to be an immaterial, timeless, transcendent being, and that could only be a personal mind, which is what we mean by God. So premise (2), I think, is also a very plausible premise. It seems to me that that is more plausible at least than its negation. That is all you need for a good argument.

3. The universe is an existing thing.

That seems obvious. The universe obviously exists, right? Moreover, the universe has many unique properties that distinguishes it as a unique object, a unique thing. It has a certain pressure, a certain temperature, a certain density, a certain expansion rate.[7] That the universe is an existing thing is especially obvious in the very, very early stages of the universe just after the Big Bang when the universe was so super dense that it was compressed down to an unimaginably tiny object. So premise (3) seems quite clearly true; certainly a plausible premise that the universe is an existing thing.

So all three of these premises seem to me to be plausible and seem to be true. But if that is the case, what follows from these premises? Well, let’s see.

If the universe is an existing thing as premise (3) states, and every existing thing has an explanation of its existence then it follows from (1) and (3) that:

4. The universe has an explanation of its existence.

That follows from step (1) and step (3). Step (3) says the universe is an existing thing. (1) says every existing thing has an explanation of its existence. So according to the rules of logic it follows that the universe has an explanation of its existence.

But then from (4) and (2) it follows that:

5. That explanation is God.

(2) says if the universe has an explanation of its existence that explanation is God. (4) says the universe has an explanation of its existence, therefore it follows from (2) and (4) that the explanation of the existence of the universe is God. So God is the explanation of the existence of the universe. Therefore, God exists.

So it seems to me that this gives us a good argument for the existence of God. It is based on three premises that are plausibly true, more than their negations, and when you apply the logical rules of reasoning, this is the conclusion that falls out.

I would encourage you to memorize these premises, to understand the defense of each of the three premises, and this is a handy dandy argument for God’s existence. It really is. I think this is a great argument.

How might the atheist try to escape this argument? Well, notice that premise (4) says the universe has an explanation of its existence. Premise (1) says the explanation of the existence of anything can either be in the necessity of its own nature or in an external cause. In premise (2) we assumed that if the universe has an explanation of its existence then its explanation is to be found in an external cause, not in the necessity of its own nature. The universe does not exist necessarily like the number 1 or the empty set. So (2) assumes that the universe does not exist by a necessity of its own nature. The atheist could escape this argument by denying premise (2) and saying, “Yes, the universe does have an explanation of its existence, but that explanation lies in the necessity of its own nature. The universe exists necessarily, just like the number 1 or the empty set.”

This would be an extraordinarily radical position for the atheist to take. Most philosophers and scientists would say the universe does not exist by a necessity of its own nature. The universe is a contingent being; it didn’t have to exist. So this is a radical position for which the atheist would need to offer us some sort of proof. He’d have to give us some evidence to think that the universe exists by a necessity of its own nature. Just to give one example. A few years ago I was at a philosophy conference at the University of California, Santa Barbara and a very prominent atheist and philosopher of physics was giving a paper there. He is a virulently atheist; very antagonistic to belief in God. I asked him in the Q&A time, “Professor Grünbaum, is it your view then that the universe exists by a necessity of its own nature?” And he became almost indignant he was so upset. He said, Of course not, I would never have said anything that absurd. The universe is obviously not necessary in its existence. So if the atheist tries to escape this argument by saying the universe’s explanation is that the universe exists by the necessity of its own nature he is taking a very radical line that would require him to give us some proof.[8] I can’t even imagine what sort of proof that is. I think on the other side, we definitely have a sort of intuition of the universe’s contingency and non-necessity. It doesn’t seem like the universe had to exist. There could have just been no universe at all. Therefore, I think the burden of proof here lies on the atheist rather than on the theist. As I say, it seems to me that (2) is a very plausible premise that the theist has very often himself affirmed.

Still, it would be nice if we could provide some further argument to show that the universe does not exist by a necessity of its own nature. What I am going to talk about next time is another argument for the existence of God which I think will supplement the argument from contingency by ruling out this alternative that the universe exists by a necessity of its own nature. But that argument, as I say, is supplementary to this argument which I think stands on its own two feet. But what we will do next time is look at the cosmological argument for the existence of God which will argue that the universe is not necessary in its existence and therefore must have a transcendent cause.

Oh, I forgot something! Some of you will ask, “If every existing thing has an explanation for its existence then what is God’s explanation?” And I forgot to mention what this argument shows is that God exists by a necessity of his own nature. Since God doesn’t have an external cause (because he is the ultimate being), what this means is, yes, God does have an explanation of his existence, namely, he exists by a necessity of his own nature. So what this argument gives you is not simply a reason for the existence of the universe or a reason for contingent being, but it grounds the existence of all contingent reality in a being whose existence is necessary – a being whose non-existence is impossible, a being which cannot not exist. If the atheist says to you, “Well, if everything has an explanation of its existence, then what of God’s existence? Ha ha ha!” You say, “That’s right, everything does have an explanation of its existence either in the necessity of its own nature or in an external cause. And God exists by a necessity of his own nature.”

That is why it is called an argument from contingency – because it gets you back to God as an absolutely necessary being which grounds the existence of everything contingent.[9]



[1] 5:05

[2] 10:14

[3] 15:03

[4] 20:07

[5] 25:08

[6] 30:03

[7] 35:02

[8] 40:16

[9] Total Running Time: 43:24 (Copyright © 2007 William Lane Craig)