Debate with Krauss (part 2)

Transcript Debate With Krauss Pt. 2

Part 2

Kevin Harris: Welcome to the Reasonable Faith podcast with Dr. William Lane Craig. Kevin Harris here along with Dr. Craig as we continue talking about the Lawrence Krauss debate. [1] There's two debates – very significant and back to back almost – that we're going to be discussing in the next few podcasts. And, Bill, I have to say, that must have worn you out to have those two to conduct back to back and also do all the prep that goes into these.

Dr. Craig: It really was exhausting—I was pretty spent after this was over. It was like crossing a mountain top and being on the downhill slope afterwards—it was a great relief.

Kevin Harris: Dr. Krauss has written some postmortem of this debate. Dr. Craig, today you're going to get an opportunity to respond to some of the things that he has written. And one of the things that you said was that you kind of delayed the response so that cooler heads will prevail.

Dr. Craig: Yes, I thought that the reaction was very emotional, and there are substantive issues here that need to be talked about. And so I'd like to just put those emotions aside and talk about the questions.

Kevin Harris: He does open his blog by saying that “It sometimes surprises me,” he says, “how religious devotees feel the need to regularly reinforce their own convictions in groups of like-minded individuals. I suppose this is the purpose of regular Sunday school services, for example, to reinforce the community of belief in between the rest of the week,” and so on. Kind of ironic since he is posting on one of the more popular community atheist sites. And one thing that the internet has allowed people to do – atheists in particular – is to get together and fellowship, reinforce each other's beliefs, pat each other on the back, and all you have to do now is sing a little bit and have some fried chicken and they'll be just like us! [laughter].

Dr. Craig: [laughter] Right. By contrast this debate was held at a state university. It is precisely in such a public forum that I'm interested in discussing these issues—not on friendly territory or in a church or Christian university, but on a state university campus. So I'm interested in having discussions of these issues in public forums on our best university campuses.

Kevin Harris: He says something very disturbing on his blog. He says, “Let me comment, now, with the gloves off, on the disingenuous distortions, simplifications and outright lies that I regard Craig as having spouted. I was very disappointed because I had heard that Craig was more of a philosopher than a proselytizer. But that was not evident the other evening.” First thing that we'll look at, though, is when is there evidence for God? And you brought out a formula.

Dr. Craig: Right. I did. I gave a formula from the probability calculus for what it means to say that there's evidence for a certain hypothesis. And in probability theory to say that there's evidence for a certain hypothesis is simply to say that that hypothesis is more probable given certain facts than it would have been in the absence of those facts. And this ought to be uncontroversial, Kevin. This is simply the way the notion 'is evidence for' is defined in probability theory—it's completely unobjectionable.

Kevin Harris: So then what constitutes evidence, in evidence for God? I've often heard it said, “Those are arguments for God; that's not evidence for God.”

Dr. Craig: Well, I listed five facts that I thought render the existence of God more probable than God's existence would have been in the absence of those facts. And those facts would be the existence of contingent beings; the origin of the universe, the fine-tuning of the universe for interactive, intelligent life; the existence of objective moral values and duties in the world; and then the resurrection of Jesus of Nazareth from the dead. It seemed to me that given these five facts that the existence of God is more probable than it would have been in the absence of those facts. And to me, Kevin, that just seems almost indisputably true. Now, that's not to say that God exists, or that it's probable that God exists. It's just to say that God's existence is more probable given those facts than it would have been without them. And that is, as I say, unobjectionable and should not be a controversial point in terms of what does it mean to say that there is evidence for a hypothesis.

Kevin Harris: Dr. Krauss seems to think that you were arguing on the basis of that – that the probability of God's existence is greater than fifty percent.

Dr. Craig: Yes, this is very odd. He complains that I asserted that therefore God's existence is more probable than not, or greater than fifty percent. And if you look at my opening speech, Kevin, I explicitly said I would not be arguing for that. And I even put up a little formula on the PowerPoint to the effect that God's existence on the evidence and background information is greater than fifty percent, [2] and I said I will not be arguing this tonight. I'm going to leave that up to you to decide for yourselves. I'm simply going to argue that God's existence is more probable given these facts than it would have been without them. [3] And therefore Dr. Krauss' complaint here, I think, is just completely misconceived. He has misconstrued my argument, and so I don't need to consider what he calls the prior probability of God's existence on the background information alone. We don't even need to consider that because we're not asking whether God's existence is more probable than fifty percent—that's not the subject for the debate that night.

Kevin Harris: Would that be a good debate topic, you think? Have you seen people put a probability on it?

Dr. Craig: Well, that would be a good topic for debate, in fact. That would be a topic that would ask the question “Does God exist?” or “Is it probable that God exists?” and would be a worthy topic for debate. But this was an unusual topic that Dr. Krauss chose. This topic was simply “Is there evidence for God?”

Kevin Harris: He immediately went to the god of the gaps, and accused you of god of the gaps reasoning.

Dr. Craig: Yes, he accused me of simply saying because I can't explain something therefore God must have done it.

Kevin Harris: Yeah, and I want our listeners to understand – and if they've listened to any of our podcasts we've addressed this over and over – it's come up in so many debates that I don't understand why Dr. Krauss hasn't heard this addressed.

Dr. Craig: I think that people like Richard Dawkins and Lawrence Krauss and others have this as a kind of stock in trade response to theistic arguments. And they're not really being attentive to the argument itself. This is just sort of their standard reply, to make the god of the gaps accusation.

But, Kevin, when you look at the arguments that I gave there were two of them that appealed to scientific evidence. And it's completely incorrect, as I explained in the course of the debate. In the two arguments that I gave that do appeal to the scientific evidence I do not appeal to the evidence as saying therefore God explains this or God exists. What I say is that we have good evidence for the premise that the universe began to exist. Now that's a religiously neutral statement that can be found in any textbook on astronomy and astrophysics. It is certainly a question that is open to scientific evidence. There can be no reason to think that this is a proposition that science could not establish to be true—that the universe began to exist. In my other argument – the fine-tuning argument – I appeal to scientific evidence to show that the best explanation of the fine-tuning is neither chance nor physical necessity. And, again, those are purely scientific statements that are open to scientific evidence. Roger Penrose has argued against chance as the best explanation on scientific grounds. Richard Dawkins has argued against physical necessity as the best explanation on purely scientific grounds. So in neither case am I appealing to evidence for God. I'm appealing to evidence to show in the one case that the universe began to exist, and the other case that the fine-tuning of the universe is not plausibly explained by chance or physical necessity.

So what I would say is that scientific evidence can establish a premise in an argument which leads to a conclusion which has theological significance. And that is not god of the gaps reasoning because the scientific evidence is used purely to establish that religiously neutral premise, like the universe began to exist.

Kevin Harris: You seem to be arguing, then, Bill, from things we do know, not from things we don't know.

Dr. Craig: Yes, I'm saying the scientific evidence supports this proposition, and that proposition, then, can serve as a premise in a philosophical argument to a conclusion that has theological significance.

Kevin Harris: You went to the existence of contingent beings next. How did Krauss handle that?

Dr. Craig: Well, this is the argument that says why do contingent beings exist? You need to have a metaphysically necessary being to ground the existence of contingent beings. And Dr. Krauss, I think, even in his post-debate comments clearly doesn't understand the argument from contingency, because what he says is, “Contingent things happen all the time and they have natural explanations, and there could be a natural explanation of the origin of the universe.” Well, merely positing another contingent being, Kevin, to explain the origin of the universe doesn't do anything to answer our question “Why are there any contingent beings at all rather than nothing, or rather than just necessary beings, like, say, mathematical objects?” [4] So he's just failed to understand the argument, and merely posits another contingent being in existence, which doesn't answer the question why do contingent beings exist?

Kevin Harris: It kind of puts the problem back a step?

Dr. Craig: Exactly—just moves the problem back a notch. And in the contingency argument, as you know, the argument has nothing to do with the origin of the universe, as Dr. Krauss seems to assume. The universe could be eternal and yet we could still ask why does an eternal contingent universe exist rather than nothing or rather than just mathematical objects? How is it that this eternal universe should exist rather than nothing, or rather than merely necessary beings? So merely positing the eternality of the past of the contingent universe just doesn't go any distance to answering the question “Why do contingent beings exist at all?”

Kevin Harris: The beginning of the universe—this should have been a place where Dr. Krauss just really shined. I couldn't wait to hear what he'd say.

Dr. Craig: Right, this should have been in his wheelhouse.

Kevin Harris: Yeah. Well, in his postmortem responses he's presents, coupled with the debate, three objections. One: every physical event has a physical cause.

Dr. Craig: Now, even if that were true, Kevin, notice that doesn’t do anything to refute either premise of the kalam cosmological argument, which says everything that begins to exist has a cause; the universe began to exist; therefore the universe has a cause. It doesn't refute either of those premises, therefore it doesn't refute the argument. It would simply raise the question, when you get to the cause of the universe: “Could this be a physical cause as opposed to an immaterial cause?” And what I would argue is that when you get to a cause of the universe you have to have a being that transcends space and time in order to bring space and time into existence. And therefore this cannot be a physical or material cause. So that it is the nature of the case that leads us to infer that the cause we're dealing with here has to be an immaterial or nonphysical reality, rather than a physical reality because we're dealing here with the origin of spacetime itself.

Kevin Harris: So what's shown here: a naturalistic bias of saying it's got to have a natural explanation (material or physical)?

Dr. Craig: I suppose so. One could simply ask him what warrant is there for thinking that the cause of the universe is physical or even could be physical. As I explained in the debate, the Borde-Guth-Vilenkin theorem requires that the physical universe and even the multiverse, if there is such a thing, cannot be extrapolated to past infinity. It had a beginning. And therefore space and time themselves came into being, and so the cause of the universe has to be a being beyond space and time, and therefore nonphysical and immaterial.

Kevin Harris: Have you been able to ascertain what Dr. Krauss thinks of the Borde-Guth-Vilenkin theorem?

Dr. Craig: No, I haven't, Kevin. And this was a big surprise to me because I had anticipated – since I was using this in my opening speech – that he would attempt to challenge that theorem, or perhaps to craft some models of the universe that escaped the theorem, and could restore an eternal past. But he didn't try to do that at all.

Kevin Harris: “The ekpyrotic cyclic model of Paul Steinhardt and Neil Turok will avoid the beginning of the universe.” In other words if you want to try to avoid the beginning of the universe, well, this is the model that will do it.

Dr. Craig: This really surprised me, Kevin, because Dr. Krauss ought to know that the Borde-Guth-Vilenkin theorem applies to the Steinhardt-Turok ekpyrotic cyclic model. It is precisely one of those so-called brane cosmologies that are governed by the Borde-Guth-Vilenkin theorem, and therefore even its proponents admit that it cannot be past eternal, but that the universe had a beginning. So I was really surprised that he made this mistake in thinking that somehow this model would restore a past eternal universe in the face of the Borde-Guth-Vilenkin theorem.

Kevin Harris: In fact he doesn't himself accept the Steinhardt-Turok model.

Dr. Craig: That's true. That's the irony, as well. He makes a point of saying “I don't really believe this theory, but here's how you can explain why the universe is infinite in the past.” Well, that is very odd to appeal to a false theory to try to restore the past infinity of the universe.[5] But whether he believes in it or not is immaterial in the end because, as I say, it is governed by the Borde-Guth-Vilenkin theorem and therefore cannot be past eternal.

Kevin Harris: And certain quantum gravity models: space and time are created at the moment of the Big Bang itself. Now that is something that he also said in order to avoid the beginning?

Dr. Craig: Yes, and I would say, “Exactly.” That's exactly right. In, for example, the Hartle-Hawking no-boundary proposal, or Vilenkin's quantum tunneling model, these semi-classical quantum gravity models involve an absolute origin of the universe, of space and time, in the finite past. They are not extrapolated to past infinity. And so these models support the second premise of the kalam cosmological argument: that the universe began to exist. What they do not do, and cannot do, is explain how the universe could come into being from non-being, from non-existence.

Kevin Harris: Now, Dr. Krauss is writing a book about this.

Dr. Craig: Yes.

Kevin Harris: Is his book going to be an attempt – as far as you can tell – to avoid a beginning of the universe?

Dr. Craig: I don't think so. As I understand it he wants to explain how the universe came into being from nothing, according to science.

Kevin Harris: In a sense he believes in a beginning.

Dr. Craig: I take it that he does, Kevin, because he seems to want to affirm models like the Hartle-Hawking model, for example, that does have an absolute beginning. But he thinks that these will be self-explained, that they'll explain how the universe came into being out of nothing. But what the reader has to watch very carefully is how he uses the word “nothing” because, as Dr. Krauss put it in our debate, he says there are different kinds of nothing. That is to say he's using the word “nothing” to describe what are in fact physical states of affairs, physical realities like the quantum vacuum, or this topological sector in the Hartle-Hawking model out of which our universe emerges. But these are not extrapolatable to past infinity, they're not past eternal. And so he really is equivocating on the use of the word nothing, here.

Kevin Harris: Is this the objection that goes something along the lines of, there was no moment prior to the Big Bang because moments came into being; time, space, temporality, and everything?

Dr. Craig: Yes, yes, that's right.

Kevin Harris: So therefore there would be no way for God to create because there would be no moment for the creation?

Dr. Craig: I don't know that that's what Dr. Krauss would say, but that is something that I've seen in the literature. And it is correct to say, on these models, time began to exist. That is to say there is an interval of time which is absolutely first, before which no time existed. My own position is that God, sans the universe (without the universe), exists timelessly and that at the moment of creation he enters into time in order to sustain a causal relationship with the universe, and that the moment of creation is simultaneous with the moment of the universe coming into being.

Kevin Harris: The fine-tuning of the universe. Dr. Krauss kind of appears to deny the fine-tuning of the universe.

Dr. Craig: Yes, this represented a shift of ground in the debate. He tried to explain away the fine-tuning through the many worlds hypothesis. But now he seems to want to deny the fact of fine-tuning altogether.

Kevin Harris: Well, you gave examples of fine tuning, like the subatomic weak force, the cosmological constant, the low-entropy condition of the early universe. What is his reaction there?

Dr. Craig: Well, he tries to explain two of these away as being merely apparent. He says that the initial low-entropy condition of the universe can be explained through inflationary scenarios of the universe. But, as Roger Penrose of Oxford University has said, this is simply not accurate. The second law of thermodynamics would require that in any single universe the entropy state of the universe prior to inflation would be lower than it is after inflation, and therefore you haven’t explained away the initial low-entropy condition. Now if you try to get around that by having a multiverse hypothesis then you're going to have the problem that I raised in the debate with these so-called Boltzmann brains. That is to say, you can have observable universes which are not fine-tuned for intelligent, interactive life by having these brains that just pop into being through thermal fluctuations in the vacuum and observe the illusory universe around them. [6] In order to try to explain away the fine-tuning of the universe he would have to show that these observable universes by Boltzmann brains are not a significant proportion of the observable worlds in the multiverse. And there's simply no way he can do that because these things, on any standard measure of probability, are vastly more probable than fine-tuned universes. So he could not show that observable universes have to be fine-tuned for the existence of intelligent, interactive agents, rather than just observable universes that have these Boltzmann brains in them. And he simply never responded to that, neither in the debate nor in the post-debate comments.

Kevin Harris: What about the cosmological constant that you brought up?

Dr. Craig: Ah, yes. What he says here is that the cosmological constant – which is responsible for the acceleration for the expansion of the universe – could be decreased right down to zero without detriment to life. And that's true—that's correct. But, as he himself admits, it cannot be very much increased without disaster because then the universe would accelerate so rapidly that galaxies and stars and planets would never form, and you would have no sites on which life could evolve. So the cosmological constant exhibits what Robin Collins calls one-sided fine-tuning. That is to say it can't be increased very much in one direction, even though it could be decreased in the other direction. And when you take the range of life-permitting values of the cosmological constant and you compare it to the range of possible values it's infinitesimally small, Kevin. So that it most definitely is one of the most powerful evidences of fine-tuning that there is in the cosmos.

Kevin Harris: So he seems to deny all these amazing fine-tuning constants and quantities.

Dr. Craig: Yeah, that's a little bit surprising because I think that the majority of physicists would say that the fine-tuning is here to stay, and that any attempt to craft a higher theory that would explain certain values of these constants or quantities will itself involve fine-tuning of other constants or quantities, so that whatever the final theory is it's going to exhibit this kind of fine-tuning.

Kevin Harris: We're still going to have to fight the anthropic principle – I guess it's going to come up – and it seems to come up here a little bit.

Dr. Craig: Yes.

Kevin Harris: Aren't Boltzmann brains the observers that would come in and they would say, “If there would be no one here to observe it then we're only reporting what we observe.”

Dr. Craig: Yeah, and that's his final gambit. He tries to deny the reality of fine-tuning, but when push comes to shove he'll appeal to the many worlds hypothesis, and the fact that you can only observe a universe that is fine-tuned for your existence. And the problem is that's just demonstrably false, as you said, because you could have a world that is observable by Boltzmann brains and that wouldn’t be fine-tuned for the existence of intelligent, interactive life. And so he really hasn't been able to show that observable universes have to be fine-tuned for the existence of these interactive agents in the way that it is.

Kevin Harris: That would be a good name for a rock group: Boltzmann Brains—don't you think?

Dr. Craig: [laughter] Yeah.

Kevin Harris: Well, there's another thing that he said against fine-tuning for life. He says, “We have no idea if other values would allow other non-human-like intelligent life forms to evolve.”

Dr. Craig: Yeah, and I think that that's just a misunderstanding or a failure to appreciate the truly disastrous effects if these constants and quantities weren't fine-tuned. For example the cosmological constant. As I said, if it were much increased the universe would just fly apart so that there would never even be planets on which any sort of lifeforms could evolve. In many cases there wouldn't even be matter, there wouldn't even be chemistry, Kevin. So I think he's simply failing to appreciate the truly, truly disastrous effects that would result in the absence of the fine-tuning of these constants and quantities.

Kevin Harris: I'm curious if certain people are – perhaps Dr. Krauss, as well – saying this: that there could be life forms that were not made of carbon atoms, such as we were. And they may end up being intelligent, or things like that.

Dr. Craig: That has been suggested – maybe silicon could be used – but, again, biologists and physicists who have examined the properties of carbon compared to silicon have shown that silicon would not enable an organism to be a functioning, reproducing organism, so that silicon based life would in fact be impossible.

Kevin Harris: Well, even if it were possible, if there were no planets and no matter.

Dr. Craig: Yeah, exactly. Right, if there's not even any elements for chemistry it wouldn't matter.

Kevin Harris: Again, the many worlds hypothesis – that seems to be the going thing right now to try to get around God, if you want to just get down to brass tacks. If there are many universes odds are we would certainly expect to find ourselves only in those in which we can live. And so the odds are in favor of us being here.

Dr. Craig: Right, and that is the chief alternative today to theism. This is where the debate lies: many worlds verses theism. And the problem or the challenge for these many worlds theorists is they've got to answer the problem of these Boltzmann observers because it is simply false that only fine-tuned universes can have observers in them, which is what Dr. Krauss is claiming or assuming here.

Kevin Harris: You call some of these many worlds hypothesis bloated ontologies that just require really preposterous scenarios and multiple universes, and universes that look like a loaf of bread . . .

Dr. Craig: It's a lot to ask for in order to avoid a cosmic designer – isn't it? – and especially if you have other independent arguments for a cosmic creator then why go to these extravagant metaphysical lengths to avoid the existence of such a being?

Kevin Harris: There's some other things that Krauss has written after the debate and, Bill, next time we'll want to pick up on that—your responses to some of the things that he has said. We'll do that on the next podcast from Reasonable Faith. Thank you for being here. [7