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- [00:04]
A
Welcome to Defenders, the teaching class of Dr. William Lane Craig today. An Excursus on Natural Theology, Part 14. For more resources from Dr. Craig, go to reasonablefaith.org in our study of the doctrine of God, we've embarked upon an excursus on natural theology or arguments for God's existence. And so far we've surveyed the proper physicality of belief in God, the contingency argument for God's existence, and the Kalam cosmological argument for God's existence. And today we're going to turn to a new argument, the teleological argument for God's existence or the old argument for design. The importance of this excursus was brought home to me afresh this week and as I watched a video of a Veritas forum at Ohio State University from last year featuring a Christian Scientist and an atheist philosopher. And the atheist philosopher's main point was that there's just no evidence for God's existence and therefore it would be unjustified to believe in him. And therefore we should simply affirm that God does not exist and that there is no ultimate meaning to life in the sense of a point or purpose to our existence. And it struck me that he made no effort at all to defend his position. He simply asserted it. He never examined the position that it can be rational to believe in something not on the basis of evidence that there are properly basic beliefs and, and that in fact, the idea that only beliefs based upon evidence can be rational ultimately leads to skepticism and is self defeating. Moreover, he never looked at any of the arguments for God's existence that we've surveyed in this class. So it's, I think, extremely important that we as Christians, if we're to commend our faith in a culture that's increasingly secular and skeptical, be able to offer arguments for God's existence, or to defend the rationality of belief in God in the absence of such arguments. Now today we want to turn to the teleological argument or the argument for design. This is one of the oldest arguments for God's existence. Ancient Greek philosophers like Plato and Aristotle were struck with the order that pervades the cosmos. The stars and the planets in their constant revolution across the night sky were especially awesome to the ancients. Plato's academy lavished extensive time and thought on the study of astronomy because Plato believed it was the science that that would awaken man to his divine destiny. According to Plato, there are two things that lead men to believe in God. First, the argument from the existence of the soul and Then secondly, the argument from the order of the motion of the stars and of all things under the dominion of the mind, which ordered the the universe. Plato employed both of these arguments to refute atheism and concluded that there must be a best soul who is the maker and father of all, the king who ordered the primordial chaos into the rational cosmos that we observe today. An even more magnificent statement of divine design is to be found in a fragment of a lost work of Aristotle entitled On Philosophy. Aristotle, too, was filled with wonder at the majestic sweep of that glittering host across the night sky of ancient Greece. And anyone who has personally studied the heavens, I think, has to turn a sympathetic ear to these thinkers of antiquity who gazed up at the night sky, as yet undimmed by pollution and the glare of city lights, and watched the slow but irresistible turn of the cosmos, replete with its planets, stars and familiar constellations across their view, and wondered, what is the cause of all this? Aristotle concluded that the cause was divine in intelligence. He imagines in this work the impact that the sight of the world would have upon a race of men who had lived underground their entire lives and never beheld the sky and one day managed to escape from their subterranean prison. He writes, when thus they would suddenly gain sight of the earth, seas and the. And the sky, when they should come to know the grandeur of the clouds and the might of the winds, when they should behold the sun and should learn its grandeur and beauty, as well as its power to cause the day by shedding light over the sky. And again, when the night had darkened the lands and they should behold the whole of the sky spangled and adorned with stars and. And when they should see the changing lights of the moon as it waxes and wanes, and the risings and the settings of all these celestial bodies, their courses fixed and changeless throughout all eternity, when they should behold all these things, most certainly they would have judged both that there exist gods and that all these marvelous works are the handiwork of. Of the gods. In his book Metaphysics, Aristotle proceeded to argue that there must be one first uncaused cause, which is God, a living, intelligent, immaterial, eternal, most good being who is the source of order in the cosmos. Reading the works of these ancient philosophers, you cannot help but think of Paul's words in his letter to the Church of Rome. Ever since the creation of the world, his invisible nature, namely his eternal power and deity, has been clearly perceived in the things that have been made. Romans 1:19. From earliest times, men who have Been wholly ignorant of the Bible, have concluded, on the basis of the design in the universe, that God must exist. And today, many astronomers, As a result of recent discoveries, Are coming to a similar conclusion. Scientists used to think that whatever the conditions of the early universe Might have been like, Given sufficient time and and some luck, Intelligent life forms like us Would probably evolve somewhere in the universe. As a result of discoveries over the last 50 years or so, we now know that that assumption was wrong. In fact, quite the opposite is true. Astronomers have been stunned by the discovery of how complex and delicate a balance of initial conditions and must be given in the big bang itself if the universe is to permit the existence of intelligent life Anywhere at all in the cosmos. This delicate balance of initial conditions has come to be known as the fine tuning of the universe for life. We've come to discover that the universe Is incomprehensibly fine tuned for the existence of intelligent life. Now, this fine tuning of the cosmos Is of two sorts. There are first the constants of nature, and then there are certain arbitrary quantities. First, the constants of nature. What is a constant? Well, when the laws of nature Are expressed As mathematical equations, you find appearing in them certain symbols which stand for unchanging quantities, like the force of gravity, or the electromagnetic force, or the subatomic weak force, and so forth. And these unchanging quantities are called constants. The value of these constants Is not determined by the laws of nature. There could be universes Governed by the same laws of nature as ours, and yet with different values of these constants. The actual values of these constants Are therefore not determined by nature's laws. The laws of nature Are consistent With a wide range of values of these fundamental constants. And depending upon the values of these constants, Universes governed by the same laws of nature Will look radically different. Now, in addition to these constants, There are also certain arbitrary quantities which are just put in as initial conditions on which the laws of nature then operate. And because these quantities are arbitrary, they're also not determined by the laws of nature. A good example of such a quantity Would be the amount of thermodynamic disorder or entropy in the early universe. It's just given in the big bang as an initial condition. And then the laws of nature take over and determine how the universe will develop from there. But if those initial quantities had been different, if the level of entropy or disorder in the early universe had been different, Then the laws predict that a very different sort of universe Would have evolved. Now, what scientists have been stunned to discover in recent decades is that these constants and quantities must fall into an extraordinarily narrow range of life permitting values if the universe is to permit the evolution and existence of intelligent life anywhere in the cosmos. And this is what is meant by the fine picture tuning of the universe. So it's important to understand that the term fine tuned does not mean designed. The term fine tuned does not mean designed. Rather, fine tuning is a neutral expression which doesn't say anything about how the fine tuning is best explained. Fine tuning just means that the range of life permitting values for these constants and quantities is exquisitely narrow. If the value of even one of these constants or quantities were to be altered by less than a hair's breadth, the delicate balance required for the existence of life would be upset and the universe would be life prohibiting instead. All right, well, let's look at some examples of fine tuning. Fine tuning in this neutral sense is fairly uncontroversial and well established. Physics abounds with examples of fine tuning. Now, before I share a few of these examples, let me just give you some numbers to give you a feel for the delicacy of of this fine tuning. The number of seconds in the history of the entire universe since the Big bang is said to be 10 to the 17th. That's one followed by 17 zeroes. An incomprehensible number. The number of seconds in the history of the universe since the Big bang. The number of subatomic particles in in the universe is said to be somewhere around 10 to the 80th particles. The number of subatomic particles in the entire known cosmos is said to be somewhere around 10 to the 80th. Now, this is simply an incomprehensible number. We have no idea really of what something like this means. It is beyond human imagination. Now, with these numbers in mind, consider the following. Both the force of gravity and the atomic weak force are so finely tuned that an alteration of their values by even one part out of 10 to the 100th power would have prevented a life permitting universe. Similarly, a change in the value of the cosmological constant which drives the acceleration of the universe by even one part out of 10 to the 120th power would have rendered the universe life prohibiting. Here's a real corker. Roger Penrose has estimated that the odds of our universe's early low entropy condition, that initial condition of the low entropy in the universe occurring by chance, is somewhere on the order of one chance out of 10 to the power of 10 to the power of 123. A number which is so incomprehensibly large that to call it astronomical would be a wild understatement. Clearly the fine tuning that we're talking about here is literally beyond human comprehension. Having an accuracy of even one part out of 10 to the 60th power would be like having an aim so accurate that you could fire a bullet at a target on the other side of the universe, 20 billion light years away and nailing a 1 inch bullseye. And that number is insignificant compared to numbers like 10 to the 120 or 10 to the 100th. And it's not just each quantity or constant that must be finely tuned when you multiply these together, that they must all fall into the exquisitely narrow life permitting range. We're dealing here with numbers that are simply incomprehensible. So the examples of fine tuning are many and various, and therefore they are not likely to disappear with the future advance of science. Their multiplicity, that is to say their numerosity, the number of them, and then their variety, they're different, make it highly unlikely that these numbers are going to be done away with or disappear with the advance of physics. Like it or not, fine tuning is just a fact of life which is scientifically well established. Now you might be thinking at this point, but if the constants and quantities had had different values, then maybe different forms of life might have evolved. But that underestimates the really disastrous consequences of a change in, in the values of these constants and quantities. When scientists talk about a universe as being life permitting, they're not talking about just present forms of life. By life, scientists mean the property of organisms to take in food, extract energy from it, grow, adapt to their environment and, and reproduce. It's the property of an organism to take in food, extract energy from it, grow, adapt to their environment and reproduce. And anything that fulfills those conditions counts as life. And the point is, for life so defined to be possible, whatever form it might take, the constants and quantities of, of the universe have to be unbelievably fine tuned, otherwise disaster results. In the absence of fine tuning, not even matter, not even chemistry would exist, much less stars and planets where life might evolve. Any comment or question on that aspect of the fine tuning argument? Yes, don't. Just a question about those astronomical numbers. Yes. What kind of parameters does somebody use to even calculate those kind of numbers? And is there any rational basis for it? Oh yeah, there's definitely rational basis for it, Don. What they do is they simply increase the Value, say, of gravity a little bit. And what you would discover then, when you run the laws of physics with a slightly stronger gravitational constant, is that everything will collapse in on itself and the universe will collapse into a black hole. On the other hand, if you just marginally weaken the force of gravity a little bit, then the laws predict that the universe would just expand so rapidly that stars and planets would never congeal, and so there would never be any sites on which life could exist. So because we're talking about universes governed by the same laws, physicists can alter these values and then run the laws and predict what sort of consequences would ensue. And what they find is, as I say, that if you alter these values by even a hair's breadth, stronger or weaker, then the universe turns out to be life prohibiting rather than life permitting in some way or other.
- [19:56]
B
So this very similar to your question. I was discussing this argument with some atheists at Georgia Tech once, and we kind of came to a stopping point where they were discussing how you would actually come up with this probability. It seemed that they were kind of making an argument from like a. Like what you would call a frequentist philosophy of, like, probability, which states that you can't say something's a possibility until you've actually observed it. So I wondered if this would be more like an epistemic philosophy of probability where you can just. It's a hypothetical reality.
- [20:33]
A
I've dealt with this objection in my chapter on fine tuning and reasonable faith. I wasn't going to say anything about it here, but let me say something about that. Do you understand what the objection is? The objection is that probability means that something will happen, say, one time out of 10. It's a frequentist analysis of what probability is. And therefore, if you've never observed, say, 10 trials, you don't know what the probability is of something occurring. And obviously there's only one universe. So it's meaningless to talk about the probability of the universe being fine tuned because there is only one trial, so to speak. And so we can't speak of the probability of the fine tuning. I think this is quite mistaken. In the first place, a frequentist analysis of probability is mistaken. Just to give an illustration of this, scientists are investing thousands of man hours and millions of dollars in research looking for an event of proton decay in reactors. They're trying to detect the decay of a proton into more fundamental particles. This has never been observed, even though physics predicts that it can happen. Now, on the frequentist model, that means that they are looking for an event that has zero probability because it never happens. And yet that's obviously wrong. Scientists are not wasting millions of dollars and thousands of man hours looking for this because it's an event of zero probability. So the analysis that the frequentist gives simply isn't applicable here. So how should we understand probability? Well, John Barrow, who is a physicist at Cambridge University, gives the following illustration. He says, let's take a piece of paper and put on it a red dot and let that red dot represent our universe with its values of the constants and quantities. So this is our universe characterized by the constants and quantities that it has. Then he says, let's alter those constants and quantities by a tiny amount. And this is a new universe. If it's a life permitting universe, make another red dot in the vicinity of the first. If it's a life prohibiting universe, he says, make it a blue dot. Now, I don't have a blue marker, so I'll make a black dot and then do it again, and do it again and do it again and do it again until your sheet is filled with dots. And what you wind up with, he says, is a sea of blue with only a couple of pinpricks of red. And it's in that sense that a finely tuned universe is highly improbable. The values of the constants and quantities are such that only an exquisitely tiny number of values will be consistent with the permission of life. The vast majority of these possible universes are are life prohibiting. And so I think that gives us a pretty clear sense in which we can say that the existence of a finely tuned universe is incomprehensibly improbable?
- [24:08]
B
Sure. Could you also say that some of these numbers were created from simulations that scientists started to use for other scientific inquiries that have actually yielded results, and that this would be a lot more favorable of a calculation.
- [24:24]
A
Therefore, I don't know the answer to that question. Whether or not by contemplating universes where, say, the weak force in the atomic nucleus had a stronger value, this would lead to some sort of fruitful prediction. I don't know whether these sorts of predictions have that kind of practical value. What they disclose, rather instead, is that these other universes would be life prohibiting, that there wouldn't be any life as we've defined it in these kinds of worlds, that it would result truly in disaster. As I say, there wouldn't even be chemistry in these worlds if you upset the balance of these constants and quantities.
- [25:10]
C
Taewon, Dr. Craig, has anyone ever attempt to come up with the initial entropy value in contrast with what it is today.
- [25:23]
A
Oh, yes. That's what Penrose does in his estimation. He calculates back to the initial entropy condition of the Big Bang, and he finds that it is exquisitely low, that the early universe has a very, very, very low entropy condition, which is highly improbable, incomprehensibly improbable. It should be much higher than it is. And so this is something that cries out for explanation and that scientists have tried to find an explanation of.
- [26:03]
C
And if the rate of increase of entropy is consistent, you can almost. If there's initial value versus now you can calculate the age of the universe.
- [26:17]
A
Well, it would be related. What you would do is you would look at the current entropy levels and then run that backwards to a universe that is this old and then stop. And that would give you the initial low entropy condition. I'm vaguely familiar with Dembski's universal probability bound. Could you explain? William Dembsky is an intelligent design theorist who has tried to develop a model for making design inferences. When are we justified in inferring that something is designed? And as part of his theory, he sets this probability bound where anything that is more improbable than this is so outrageous that it. It would never happen. And therefore you could say that it is impossible. And his probability bound is related to that figure of 10 to the 80th subatomic particles in the universe. Anything that has a probability which is less than 1 chance out of 10 to the 80th is impossible. It just never happens. And as you can see, the fine tuning that we're talking about for even just one constant or quantity exceeds this probability bound that Dembski sets. But why does he equate that to the number of particles in the universe? Well, I think his idea is that you would look at the chances for something to occur. And if you identify a chance with a subatomic particle or position that that would give you the number of chances for this event taking place, then I suppose you would have to extrapolate that in time as well. But I don't remember his exact bound. But it's something on this order and it's far, far below the odds that we're talking about for fine tuning. This is in his book the Design Inference, published by Cambridge University Press, if anybody is interested in following that up.
- [28:39]
C
Yes, Cindy, to me, I think what we can accept is the fact that the scientific community agrees that the fine tuning is a reality. There's no question about that.
- [28:53]
A
There are scientists who will want to dispute it. And I think partially because they see where it's leading.
- [28:59]
C
That was my.
- [29:00]
A
But, but, but the majority, yes, will say that the fine tuning is well established.
- [29:05]
C
It's sort of like the elephant in the room. I'm not sure how you can dance around it and not see it. But so really it gets down to it exists. But how it exists is that where they're coming from? And they would argue around the elephant
- [29:23]
A
rather than that's what we'll, we'll be coming to. I'm laying out here the data to be explained. But as we'll see next time, there are three explanations that are offered in the current literature as to how best to explain this fine tuning. Physical necessity, chance or design. And so the debate will be not really about the fact of fine tuning, which is pretty well established. It's going to be about how do you best explain it. And as we'll see, those who deny design are driven to some rather radical metaphysical hypotheses in order to explain away the fine tuning. All right, one more question before we close. Yes.
- [30:13]
B
So if there is a condition, let's say if it's not equal to one,
- [30:20]
A
then the universe couldn't exist. I'm just saying, as a hypothetical example,
- [30:25]
B
what would be the max, how can
- [30:26]
A
you tell the maximum range that the probability or the maximum number that you can reach before. All right, this is a very, very good question that is much discussed. Let's let this represent the range of values that a constant or a quantity might take. And what we discover is that the range of life permitting values is exquisitely narrow. It has to fall within this range in order to be life permitting. And the question is, how far out does this wider range of possible values go? Does it go to infinity? Or is there some finite extent? And that question is much controverted. Robin Collins, who is probably the best writer on fine tuning today, says that the contrast between the life permitting range and the possible range should be the range of values for which we can say physically whether the universe would be life permitting or not. He calls this the illuminated range. And this illuminated range will be the range of values which are possible for which we can make a judgment. Yes, this would be life permitting. No, this would not be life permitting. Beyond that is a sort of dark, unilluminated range. And we simply don't know what is out there. And so he compares the life permitting range to the illuminated range. And that's how he comes up with these sorts of extraordinary figures about the degree of fine tuning that is necessary in order for embodied, conscious agents like ourselves to exist. All right. Well, next time we will consider a couple more objections to the argument, and then we will state and begin to unfold the premises of this argument. Let's bow our heads for benediction. And now may the Christ of Christmas, whose birth we celebrate at this season of the year, fill your hearts with joy and with love that we might understand the depth and length and breadth and to know the love of Christ and so be filled with all the fullness of God. Amen. The copyright for the content of this recording is held by Dr. William Lane Craig. For more, go to reasonablefaith.org.