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Science, Philosophy, and the Sean Carroll Debate

August 09, 2015     Time: 28:31
Science, Philosophy, and the Sean Carroll Debate

Summary

Is God deluding us? What are "brute facts"? These and more are discussed in a critical response to the debate with Sean Carroll

Transcript Science, Philosophy, and the Sean Carroll Debate

 

KEVIN HARRIS: Welcome to Reasonable Faith with Dr. William Lane Craig. I’m Kevin Harris. I ask the questions and try to stay out of the way on this podcast, and not say anything dumb, and learn along with you.

People are still talking about the debate and dialogue between Dr. Craig and cosmologist and physics professor Dr. Sean Carroll.[1] Today one of their colleagues weighs in on the debate. Because of that, you and I get to deepen our understanding of the universe and learn more about its origins. Let me encourage you to work through some of the more advanced material that we cover on these podcasts. You may hear some things with which you are not yet familiar, but you can always cross-reference so much of what we discuss with the resources available at ReasonableFaith.org. So stick with it, and we are here to help.

Dr. Craig, Dr. Don Page has written a response to your exchange with Sean Carroll.[2] Let’s look at it. First of all, who is Don Page?

DR. CRAIG: He is a very eminent cosmologist. He has collaborated with Stephen Hawking in the past. He is at the University of Alberta in Edmonton, Canada. When I’ve had occasion to speak at the University of Alberta, I’ve been able to sit down with Don over lunch and talked through some of the issues in cosmology. He has been helpful to me. I correspond by email from time to time on various issues. He is a Christian. He is a quite conservative Christian, but he is also very eccentric. He holds some really off-the-wall views I have to say. He believes that everything is determined. He is a complete fatalist who doesn’t think that anything else is logically possible than what actually is. So he has got some really, really strange views. He has been very resistant to the efforts of Christian philosophers to try to disabuse him of some of these views. Don is a kind of wild guy, but he is brilliant. It was a privilege to have him take the time to read the transcript of the Carroll debate and then to offer some comments on it.

KEVIN HARRIS: By the way there is a Molinism group on Facebook. I don’t see Dr. Page joining that anytime soon. [laughter]

DR. CRAIG: Probably not. He is very Reformed.

KEVIN HARRIS: He says that he is really kind of a combination. His views fall as a combination of both you and Carroll’s. But he says in this open letter that he wrote that was on Sean Carroll’s blog: “I tend to be skeptical of philosophical arguments for the existence of God, since I do not believe there are any that start with assumptions universally accepted.”

DR. CRAIG: I thought that was a remarkable statement. No natural theologian that I know of would say that in order to be a successful piece of natural theology you have to have an argument based upon assumptions that are universally accepted. That would be preposterous.[3] Of course one is skeptical for arguments for God's existence if they have to have assumptions or premises that are universally accepted. This is a very odd sort of reservation that he expresses about the project of natural theology. No one would set the bar that high for success in natural theology. What you would say is that the premises need to be probably true or maybe more plausibly true than false or something of that sort. But you wouldn't say that the premises need to be universally accepted.

KEVIN HARRIS: He says he has his own argument for the existence of God that he presents. It is called the Optimal Argument for God. He says, “I mainly think philosophical arguments might be useful for motivating someone to think about theism in a new way and perhaps raise the prior probability someone might assign to theism.”

DR. CRAIG: That is very valuable, isn't it? If these philosophical arguments can motivate people to reconsider the existence of God in a new way, that is a huge accomplishment, I think. Then he even says it might raise the prior probability of the existence of God. By that he means the intrinsic probability that God exists, apart from specific evidence. What is just the probability of God based on the background information? He seems to think that these are arguments could increase that probability. Again, I would esteem that to be a success in natural theology.

Notice what he goes on to say. He follows that sentence by saying,

I do think that if one assigns theism not too low a prior probability, the historical evidence for the life, teachings, death, and resurrection of Jesus can lead to a posterior probability for theism (and for Jesus being the Son of God) being quite high.

That is enormously successful in natural theology. What he is saying is that if the probability of theism on the background information alone isn't real low – even if it is low, it is less than 50% the probability that God exists – he thinks that the evidence for the resurrection of Jesus could raise that probability up above 50% so that it is now probable that God does exist and is indeed quite high. That just completely changes the picture, I think. Even if there are no philosophical arguments from premises that are universally accepted, here Don is himself presenting a cumulative case for Christian theism that results in the probability of the Christian God's existing being quite high. No apologist could ask for more than that.

KEVIN HARRIS: True! He says he “tends to favor a Bayesian approach.” We need to do a podcast on that theorem.

DR. CRAIG: We've already been implicitly talking about Bayes’ theorem, which is just the probability calculus where you would assess the probability of a hypothesis given the background information and then given the specific evidence and so forth. The argument that he gave would be such an approach based on probability.

KEVIN HARRIS: What are his oppositions here?

DR. CRAIG: He doesn't really interact much with the debate. He uses this blog more as an opportunity to share his own grounds for theism based upon, for example, the simplicity and the elegance of the laws of nature. He thinks that it may well be the case that the simpler hypothesis is theism and that therefore that is to be preferred. But he does eventually get around to the arguments from the origin of the universe and from the fine-tuning of the universe and offers some critique. Here is what he has to say with regard to the kalam cosmological argument based upon the beginning of the universe. He says, “In view of these beliefs of mine, I am not convinced that most philosophical arguments for the existence of God are very persuasive.” Remember, that is based upon thinking that to be persuasive it has to be based on assumptions that are universally accepted. I would agree with him with respect to that. But here he says, “In particular, I am highly skeptical of the Kalam Cosmological Argument.” Why? What is the basis of his skepticism? He says, “I do not believe that the first premise is metaphysically necessary.”[4] But then he adds, “I do believe that the first premise is true in the actual world.” The reason he gives for rejecting the causal premise that whatever begins to exist has a cause is that he doesn't think that is metaphysically necessary, but he does think that it is true! All the proponent of the argument needs is that it is true. You don't need that it is true in every possible world – that it is metaphysically necessary (though I think that it is). You don't have to believe the first premise is metaphysically necessary. You just have to believe that it is true and the argument will go through.

Then the second reason he gives is, “I am also not at all sure that our universe had a beginning.” Again, I would say certainty is not the proper measure here. The question is: is it more probable than not that the universe began to exist? Even a skeptic like Lawrence Krauss was willing to say in my dialogue with him, Yeah, on balance I think the universe probably began to exist.

One might ask why is he skeptical about that causal premise or why does he think it is not metaphysically necessary that “whatever begins to exist has a cause”? Here is what he says,

I agree that just from our experience of the one-way causation we observe within the universe, which is just a merely effective description and not fundamental, we cannot logically derive the conclusion that the entire universe has a cause, since the effective unidirectional causation we commonly experience is something just within the universe and need not be extrapolated to a putative cause for the universe as a whole.

What is he talking about here? What he is claiming is that if you adopt a tenseless view of time – a B Theory of time where all events in time are equally real – he says there is no reason to think that causation just runs one-way from past to later. It would be equally possible for causation to run from later to the past. That assumes that tenseless view of time which I reject as I pointed out in the debate. The kalam cosmological argument assumes from start to finish that time is tensed. That is to say, temporal becoming is an objective and real feature of the universe. The universe really did come into being at the first moment of its existence. If that is right, it would be impossible for there to be a later cause of it because that would then be to come out of nothing because that later cause doesn't exist. You can't say that the origin of the universe was caused by something later than it because there isn't anything at that point later than it. So the unidirectional nature of causation is based not in the laws of nature or in science; it is based in the objectivity of temporal becoming – that things come into being and elapse one after another. That is why causation is unidirectional. His reservations about the first premise are not scientific. Once again we see it is philosophical. It has to do with the nature of time and the nature of causation. I am ready to go to the mat in defense of the tensed theory of time and hence the unidirectional nature of causation.

What is odd, again, is that Don takes back with one hand what he gave with the other. In the next paragraph he then goes on to say,

I have a hunch that God created a universe with apparent unidirectional causation in order to give His creatures some dim picture of the true causation that He has in relation to the universe He has created. But I do not see any metaphysical necessity in this.

Here he is willing to affirm that true causation is unidirectional from God to the universe. God brought the universe into being, and he thinks that the first premise is, in fact, true that whatever begins to exist has a cause, but he doesn't see metaphysical necessity in this. That is because he doesn't think it is metaphysically necessary that God exists. He agrees with Swinburne that God is a contingent entity and doesn't exist metaphysically necessarily.

KEVIN HARRIS: He says, “I do believe, like Richard Swinburne, that God is concrete and not logically necessary, the ultimate brute fact.” When I was thinking about brute facts, I always thought that if something were the ultimate brute fact that it would be metaphysically necessary.[5]

DR. CRAIG: No, no! Not on Swinburne's view. “Brute” in this case simply means it has no explanation. But not because it is metaphysically necessary but because it is a contingent inexplicable fact. That is the sense in which it is brute – it is just a brute fact. Swinburne is willing to say that God is the ultimate explanation of why the world exists, but that God is not metaphysically necessary. He is contingent. But there just isn't any explanation for why this contingent state of affairs obtains rather than not. It is a very odd minority position within Christian philosophy that would hold that God is a contingent being whose existence is just a brute fact. But Don, as I say, is very eccentric and he buys into this view. That supplies the reasons why he thinks the first premise of the argument – whatever begins to exist has a cause – isn't metaphysically necessary, but he does think that it is true.

KEVIN HARRIS: So one can think that God is the ultimate brute fact or that the universe is the ultimate brute fact?

DR. CRAIG: Right, right. That would be the key. Then Swinburne will argue that the God hypothesis is preferable because it is simpler. Remember, Page seems sympathetic with that. Remember earlier on in his post he argues that God loves simplicity and elegance and that therefore he thinks theism could well be simpler than naturalism. So it is the preferred brute contingent fact rather than the brute contingent fact of the universe.

KEVIN HARRIS: One more time on this. He says,

I have a hunch that God created a universe with apparent unidirectional causation in order to give His creatures some dim picture of the true causation . . .

It sounds as though God is being deceptive there. Would God give us a sense of something that is not actually true?

DR. CRAIG: I do think it is rather deceptive because on the tenseless theory of time temporal becoming is an ineradicable delusion of human beings. We are – all of us – hopelessly deluded by the illusion that events happen one after another, things come into being and go out of being, and he thinks God has created us to have this illusion and that the only true causation is the causation of God to the world, which isn't illusory.

If that makes you take a deep breath, listen to the next paragraph.

Yet another hunch I have is that it is actually sentient experiences rather than created individual ‘persons’ that are fundamental, but God created our experiences to include beliefs that we are individual persons to give us a dim image of Him as the one true Person . . .

So he thinks that we don't really exist as persons. What really exists are just these experiences, and God includes this delusory belief among the experiences that “I am a person.” But in fact God is really the only person that exists. The rest is just illusory experiences that include the illusion of being an individual person. So, as I say, Don has some really radical views, and this is one of them!

KEVIN HARRIS: Before that he said, “I have a similar hunch that God created us with the illusion of libertarian free will as a picture of the true freedom that He has . . .”

DR. CRAIG: “As a picture of the true freedom that He has” – right! He thinks freedom of the will is illusory. So, boy, on Don's view God has really kind of done a job on his creatures! He has created all these illusions, to what end I wonder? I was just going to say what would the implications of Don's view be for Jesus of Nazareth? Is he a person? I suppose Don would say he is a person because he is a divine person. But that would mean that this divine person came incarnate and had interactions with all this illusory world even though he was a genuine person.

KEVIN HARRIS: He is 100% God and 100% illusory man.

DR. CRAIG: He would say, I suppose, that he has these illusory human experiences but the only person is the divine person.[6] That is orthodox Christology. There is no human person Jesus Christ. Jesus Christ is a divine person with a human nature. That would be orthodox, but it does kind of make you think about the ramifications of his view.

KEVIN HARRIS: He is skeptical about the first premise of the kalam. Now he is skeptical of the second premise, that the universe had a beginning. He says,

On the issue of whether our universe had a beginning, besides not believing that this is at all relevant to the issue of whether or not God exists, I agreed almost entirely with Sean’s points rather than yours, Bill, on this issue. We simply do not know whether or not our universe had a beginning, but there are certainly models, such as Sean’s with Jennifer Chen that do not have a beginning. I myself have also favored a bounce model . . .

DR. CRAIG: Right. Here he expresses skepticism with regard to whether the universe had a beginning. As Jim Sinclair, I think, has shown in our Blackwell Companion article, while there certainly are models like Sean Carroll's that do not feature a beginning, those models have been shown repeatedly to be untenable. They are either mathematically or empirically untenable. So these are not good models of the origin of the universe. They are not plausibly true. That is why, as you remember in the debate, I quote Vilenkin who examines these various models that are beginningless and comes to the conclusion that none of these is a good model of the universe. Vilenkin says that all the evidence we have says that the universe had a beginning. So it is not enough just to have models of the universe that are beginningless. The question is: are these models viable and true descriptions of the way the universe is? There I think the evidence really goes against them and supports models that have a beginning.

KEVIN HARRIS: I noticed that Dr. Page doesn't really interact with the philosophical arguments for a finite past.

DR. CRAIG: That is because those weren't featured in the debate. In this debate it was on the evidence of cosmology. I thought it would be unfair to try to argue philosophically when Sean Carroll is a cosmologist. I made a concerted effort to stay in his field of expertise – in his area of specialization – so that I couldn't be accused of trying to bring in philosophical things. It was so interesting that he continued to bring up philosophical questions when I tried to stick to the science in the debate and offered criticisms of his model in particular as to why I thought it was not a successful model for a beginningless universe.

KEVIN HARRIS: He mentioned that his view can be called the bounce model of cosmology. Expand on that a little bit.

DR. CRAIG: What he imagines, as I recall, is an infinite contraction down to a kind of minimum bottleneck, and then followed by an expansion. So if you had a spacetime diagram of the universe it would look kind of like an hourglass where the lower part of the hourglass represents the universe's contradicting from eternity past, reaching the narrow neck of the hourglass, and then re-expanding to eternity future. This is the same move that Carroll makes in the Carroll-Chen model. What I pointed out is that this model faces a fundamental dilemma. If you say that the arrow of time is determined by the thermodynamic arrow of increasing entropy then what you have in this hourglass model is not one universe, you have two universes expanding in opposite directions. Mirror universes, one expanding down so to speak (the bottom part of the hourglass) and the other one expanding up. You do not have a contraction followed by an expansion. You have two universes with a common origin expanding in different directions. That is the case if you take seriously that the arrow of entropy increase is the arrow of time, which is what Sean Carroll does. If, on the other hand, you say, no, no, that is just a physical device that we humans use for clock purposes – it is just our time keeping convention – but in fact that is not really the arrow of time.[7] In that case what you would have would be an arrow of time that goes from the lower part of the hourglass through the neck to the upper part of the hourglass. And that is thermodynamically impossible because then you have a universe which, contrary to the second law of thermodynamics, is decreasing in entropy for infinite time as time goes on until it reaches the hourglass bottleneck and then re-expands. That is thermodynamically impossible, and it would result in all sorts of chaos before the bottleneck is reached. There have been multiple studies of this that show this kind of contracting model just doesn't work. Vilenkin speaks to this as well.

Page's defense here is to say that this hourglass is not two universes expanding in opposite directions like mirror universes because you can trace a timeline from the first one through the bottleneck and into the lower one. My response to that is to say that that is just a geometrical fact. You have a spacetime geometry that shrinks down and then expands out again. You can draw your geometrical lines through it. But that doesn't represent time if you say that the direction of time is the direction of entropy increase. In that case you actually do have two mirror universes with a common origin. The fact that there could be a geometrical line from one to the other is just irrelevant to whether events in the lower hourglass are earlier than or later than the events in the upper hourglass. I think that the proponents of this model face a very deep dilemma here that will result in the model either being physically impossible or else it will be a model that still posits an origin of the universe.[8]