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Life, the Universe, and Nothing (II): Why Is There Something Rather Than Nothing?

August 2013

William Lane Craig vs. Lawrence Krauss

Sydney, Australia - August 13, 2013

Moderator - Introduction

Introduction: It is now my pleasure to introduce our moderator, Dr. Rachael Kohn. She is an academic, author, and broadcaster. Canadian born, Rachel taught religious studies at universities in Canada, the U.K., and Australia before joining the ABC in 1992. She is perhaps best known as the producer and presenter of The Spiritual Things on Radio National. She has won three international radio awards and produced documentaries for ABC TV’s Compass. She’s also gained a doctor of letters from the University of New South Wales in 2005 for services to the community, fostering religious understanding through broadcasting, public speaking, and writing. Will you now, ladies and gentlemen, please welcome Dr. Rachael Kohn and our speakers Professor Krauss and Dr. Craig!

Moderator: Welcome (to Craig).

Craig: Thank you.

Moderator: Welcome (to Krauss).

Craig: Thank you (to Krauss).

Moderator: Thank you, Peter! Hello, I’m very pleased to be the host of this night’s exciting event: the discussion on Life, the Universe, and Nothing. The questions of belief and unbelief, and where and who we are in the universe, and how we got here, continues to animate human thought today, as it has in the past since the written word gave us the Upanishads, the Sutras, and the books of the Bible, to name just three religious bodies of thought. But then there were the philosophers of ancient Greece and Rome and later of the medieval world where Muslims, Christians, and Jews exchanged philosophical and theological ideas, sometimes under duress and other times voluntarily. Today, I think, we might be engaging in these debates with a mixture of reasons. But whatever they are, rational thought and the imagination continue to chart new vistas of knowledge and plumb new depths of human and spiritual understanding.

Tonight we have two world-renowned thinkers in two very different fields and yet they overlap. As they face each other, much as our politicians recently did, my guess is that these two will be more daring, more forthright, and definitely more illuminating than we have so far witnessed in our political leaders. So let me introduce to you each of them:

Lawrence Krauss is an American theoretical physicist and cosmologist who is Foundation Professor of the School of Earth and Space Exploration and director of Arizona State University’s Origins Project. He is the author of several best-selling books including The Physics of Star Trek and A Universe from Nothing. He is an advocate of public understanding of science, public policy based on sound empirical data, scientific skepticism, and science education; and he works to reduce the impact of superstition and religious dogma in popular culture.

William Lane Craig is a Research Professor of Philosophy at Talbot School of Theology in La Mirada, California. He spent fifteen years in Europe obtaining two doctorates, one in philosophy, one in theology. He spent seven years at the Higher Institute of Philosophy at the Catholic University of Leuven, Belgium. His research interests include the interface of philosophy of religion and the philosophy of space and time, and the philosophy of mathematics. He’s authored or edited over thirty books including: The Kalam Cosmological Argument; Theism, Atheism, and Big Bang Cosmology; Time and the Metaphysics of Relativity; and Einstein, Relativity, and Absolute Simultaneity. His aim, contrary to Lawrence Krauss, is to argue that science does not nullify faith nor the existence of God.

So may I, without further ado, invite each of you in turn to give your fifteen-minute presentations successively? First, I call on Lawrence Krauss.

Dr. Krauss - Presentation

Krauss: [To Dr. Kohn] Thank you very much. That was, that was very brief. Thank you.

[To the audience] Thank you. I had a poem up so you could read something while I was being introduced.

Before I begin my fifteen minutes I want to just first of all thank all you for coming. It’s kind of amazing to see all of you here in this beautiful auditorium. But I also want to thank the City Bible Forum. Everyone has been remarkably gracious to me, personally. And I’ve come to respect everyone I’ve gotten to know in the Forum. And, and, that’s Peter, and Robin, and Emma, and Danielle, and particularly, and, right now, Ian, who provided me with some whiskey in honor of my friend, late friend Christopher Hitchens. But I think that’s one real distinction between an Australian Christian group and an American one is that I would never get whiskey at an American one. So applause to—I really would like to thank all of you, and I think they all deserve an incredible round of applause for putting this on.

O.K., so now I’m going to begin. Just so you know. I’ll check my time. O.K.

One of my—that was a long poem that I happen to like because it’s depressing, but this is a less depressing one and one of my favorite quotes which is: “The Initial Mystery that attends any journey is: how did the traveler reach his starting point in the first place?” [1] Now in some sense that’s the subject of this—of tonight’s discussion. But it’s,—you know, we’re going to discuss in some sense how the universe began—but it’s also more important because we’re at a new starting place; that’s what I want to point out. What I want to talk to you about is how we got to the starting place we are now, which actually depends upon learning and knowledge and empirical evidence. We’re at a very different starting point now than we were in an iron age when peasants wrote down some book before they even knew the, the earth orbited the sun. And so I want to try to take you to the present time.

And—but before I do that, I want to, in the interest—because I’ll be talking about full disclosure—I want to disclose a few things. I want to talk about science primarily, and that’s the reason I come—I do these kind[s] of things because I think science has an incredible ethos that’s important. It involves open questioning, no authorities (there are no scientific authorities), honesty, transparency, reliance on evidence, understanding uncertainty—which I’m sure is a topic that’s going to come up tonight—peer review, and testability. And I also believe that those things actually make the world a better place by overcoming myths, superstition, dogma, and fanatical certainty. Some of which we’ll hear later.

I, I—I also have respect for rational discussion,—I hope we’ll have one—but I also—I’ve come to know Dr. Craig a little bit. He is a fine gentlemen, and nevertheless—and it’s very difficult because he seems to be a very pleasant and gentle man. I have no respect for dishonest distortion and misrepresentation. And I do feel, unfortunately, that Dr. Craig does that considerably. In Brisbane I discussed it at greater length, and that’s, that’s coming out on video, so I don’t want to waste that—your time; you can watch that video. I think—I hope to demonstrate some of that tonight when it comes to the science.

And, also, clearly, this is an amazingly complex topic, and neither Dr. Craig nor I are going to have time to do it justice. But I hope, at the very least, to raise questions and to raise discussion, and I hope that is what we’ll both do—and motivate, in particular, skeptical thinking—not just about him, of course, but about what I say—and rational and open inquiry. O.K. Good.

Now, now once we get to the discussion it’s going to turn to gobbledygook. So I thought I’d at least—so it wouldn’t be a total lost cause—I’m going to give you a ten-minute science lecture because—so that way, at least, if the rest of it turns into philosophical mumbo jumbo, at least there will be some content.

So the question is: Why is there something, rather than nothing? And there are lots of different ways to answer it. You could write a book about it, which doesn’t say anything about anything. It doesn’t explain anything. Or you could do—you could do something else: you can ask the universe! And that’s the point. The main point of what I often try to convey is the sense that we force—should force our beliefs to conform to the evidence of reality. And if we understand that about the universe, we should look at the universe and try to learn from the universe, and whether we like it or not, accept those results; not something we like, but the way it actually is.

O.K., so the main thing—the first thing that I want to get straight is, in fact, modern cosmology essentially began observationally eighty-some-odd years ago when (ninety years now, almost) when Edwin Hubble (eighty years ago, I guess) discovered that the universe is expanding. So Edwin Hubble was looking out ([pointing to his diagram] these are not sperm, these are galaxies) —but, and what Edwin Hubble discovered when he looked out, remarkably, was that if you look out at distant galaxies, they’re all moving away from us and those that are twice as far away are moving twice as fast, those that are three times as far away are moving three times as fast and so on. Now when you look at this it drives you to the Christian worldview: that we’re the center of the universe. But of course that’s wrong, like everything else about the Christian worldview. It—we get that impression because of our myopic place: we are stuck in our universe—most of us are (as I often say, the Republican party in my country isn’t, but the rest of the . . . many of the other people—most of us are stuck in our universe), so to see that this really implies that the universe is expanding we have to get outside of our universe, which is something we may—which may actually be possible in the real world, but, in fact, now it’s very simple.

I can create—sorry—I can create a universe—a two-dimensional universe—that I can watch very easily, and from the outside—see I put galaxies here at regular intervals. And you can see at time T1 that that region of the universe is smaller than it is at time T2. It’s expanding. You can see it from the outside. But what would you see if you lived in that universe? Well pick a galaxy, any galaxy—say, that one. To see what you’d look like from that galaxy, I just want to superimpose this image on top of this one, putting that galaxy on top of itself. What do you see? You see exactly what Hubble saw: every galaxy is moving away from you, and those that are twice as far away from you are moving—have moved twice the distance in the same time, those that are three times as far away have moved three times the distance, and so on. And the point is, it doesn’t matter what galaxy you pick. It happens for any galaxy. So it depends on your theology, I suppose. Either there is no center of the universe or every place is the center of the universe. It doesn’t matter. That’s semantics. The point is: there’s no special place. Every place is the same and we are just in some random place. And what Hubble discovered is that the universe is expanding. Well that changed everything, as I’m sure Dr. Craig will point out, too. It meant, of course, if you worked backwards it appears that the universe had a beginning.

But it also implies something else. It also implies that the universe may have an end. Because if it’s expanding, the question is: what will happen in the future? Many of us are worried about the future, not about the past. And it turned out Einstein told us an amazing thing: matter and energy curve space. And because of that the universe can exist in one of three different geometries: so-called open, closed, or flat. And, you know, I can’t draw three-dimensional curved universes. I can draw two-dimensional curved universes, so these are analogies. But in a, in a three-dimensional closed universe, if you looked far enough in that direction, you’d see the back of your head. O.K. I can’t, I can’t draw the picture for you. But so—this is a closed two-dimensional universe, an open one, and a flat one. And the big question of 20th century and 21st century cosmology became: Which universe do we live in? Because as you add matter, you go from an open universe—if you add energy, you go from an open universe to a flat universe to a closed universe. And interestingly if you live in a universe full of matter a closed universe will expand and then contract in a Big Crunch, the reverse of the Big Bang, whereas an open universe will go on expanding forever. So if you want to find out if the future is fire or ice, you have to weigh the universe. And that’s what we spent about one hundred years doing. And the key quantity that we need to measure is this quantity—physicists, whenever we have an important quantity, we give it a Greek letter to sounds scholarly—and we call this Ω. Ω is the ratio of the actual density of the universe divided by the density of an exactly flat universe. So if Ω is bigger than one, the universe is closed; if it’s less than one, the universe is open. And we’ve been trying to measure Ω for ninety years. And we now know the answer, (I don’t have time to tell you. I’m happy to talk about it in the question period if you want) we have discovered, remarkably, that Ω (as far as we can tell) is precisely equal to one: we live in a flat universe. And that’s not flat like a pancake. That’s a flat universe [holds up hand demonstrating x, y, and z-axis]. It’s just one where the three axes, the x, y, and z-axis (and notice I said zed because I’m in Australia) point in the same direction absolutely everywhere. Just the universe you always thought you lived in. So Ω is equal to one. That’s an amazing discovery.

Now I want to take you back to one of your favorite times in school: high school physics. And I want to ask the question: How will the universe end? We are going to focus on the beginning, but it turns out beginnings and endings are irrevocably tied together, not just in literature but in reality. So to answer the question, “How will the universe end?” I can ask the question, “What happens if I throw a coin up in the air?” As you may have learned in high school—probably, in Australia, in primary school—if I throw a coin up in the air it comes back down. If I throw it up harder, it comes back down. If I throw it up really hard, hard and there is no ceiling, it doesn’t come back down at all. And physicists, we teach high school students how to do the calculation: When will a coin escape? Well, we write down the total energy of the coin (I’m sure this brings back fond memories)—there’s a—it doesn’t matter what it is—there’s a positive piece we call the kinetic energy and a negative piece we call the—potential energy. And the amazing thing is we turn it into bookkeeping; we turn the whole thing into bookkeeping. Because it turns out, if the total energy is positive, the coin will escape. If the total energy is negative (so this term beats that term) the coin will come back down.

Well, we can do the same thing for the whole universe. If we look at Mr. Hubble, and we’re standing here, we can ask, “What’s going to happen to the universe?” Well, if the universe is the same everywhere, then whatever happens to every galaxy will happen to any galaxy. So we just have to look at a given galaxy and ask, “Will it escape? Will it keep going forever?” And the positive piece, the velocity of that galaxy, depends on something Mr. Hubble measured called the Hubble constant, the expansion rate the universe. The negative piece comes from the mass density of the universe. And we just compare those two. If B, if the negative piece, is bigger than the positive piece, or B/A is bigger than one, the universe will collapse (if it’s matter dominated). If B/A is less than one, it will expand forever. But what we’ve—what is really amazing, is that B/A is nothing other than this quantity Ω, which we’ve measured to be precisely one. And that means B is precisely equal to A. And what does that mean? That means the negative piece is precisely equal to the positive piece. And what does that mean? That means the total energy of the universe is precisely zero. Now if you were going to create a universe from nothing, what would you make the total energy? That’s the first hint that perhaps you could create a universe with a hundred billion galaxies, each of which contains a hundred billion stars, from absolutely nothing without any supernatural shenanigans.

Now, “nothing” is an interesting concept. And, in order to try and shorten things, I actually discovered this week a video of me in two minutes and thirty seconds talking about it. I figured I couldn’t do it that fast on stage, so here you go:

"When you think about nothing you have to be a little more careful than you normally are because, in fact, nothing is a physical concept because it’s the absence of something, and something is a physical concept. And what we've learned over the last one hundred years is that nothing is much more complicated than we would have imagined otherwise. For example, the simplest kind of nothing is the kind of nothing of the Bible, say, an infinite empty space, an infinite dark void of the Bible. You know, nothing in it, no particles, no radiation, nothing. Well that kind of nothing turns out to be full of stuff, in a way, or at least much more complicated than you might have imagined. Because, due to the laws of quantum mechanics and relativity, we now know that empty space is a boiling, bubbling brew of virtual particles that are popping in and out of existence at every moment. And, in fact, for that kind of nothing, if you wait long enough, you are guaranteed by the laws of quantum mechanics to produce something. So the difference between empty space with stuff it and empty space with nothing in it is not that great anymore. In fact, they’re different versions of the same thing. So the transition from nothing to something is not so surprising.

Now you might say, “Well that’s not good enough because you have space. Where did the space come from?” Well, a more demanding definition of nothing is no space. But, in fact, once you apply the laws of quantum mechanics to gravity itself, then space itself becomes a quantum mechanical variable and fluctuates in and out of existence. And you can literally, by the laws of quantum mechanics, create universes, create spaces and times where there was no space and time before.

So now you’ve got no particles, no radiation, no space, no time. That sounds like nothing. But then you might say, “Well you know what, you’ve got the laws of physics. You got the laws of nature. The laws themselves are somehow something,”—although I would argue, in fact, that is not at all obvious or clear or necessary. But even there it turns out physics potentially has an answer because we now have good reason to believe that even the laws of physics themselves are kind of arbitrary. There may be an infinite number of universes, and in each universe that’s being created the laws of physics are different; it’s completely random. And the laws themselves come into existence when the universe comes into existence. So there’s no preexisting fundamental law. Anything that can happen does happen, and therefore you’ve got no laws, no space, no time, no particles, no radiation. That’s a pretty good definition of nothing."

So, science has demonstrated that, in fact, that it’s not only plausible but likely that you could create a universe from nothing by the laws of quantum mechanics and relativity. And a measurement, which could have been falsified—every property of the universe that we measure is consistent with the universe which came from nothing by the laws of physics. Does that prove it was the case? Absolutely not! But it makes it plausible, which is a key point, without miracles.

The other key thing is that “nothing,” in my case—we’ll talk a lot about “nothing.” I’m sure, in fact, we probably will—but the—“nothing” is the absence of everything that characterizes our universe. You could make lots more fancy definition of “nothing,” but the real miracle that the Bible is trying to explain is how you get all this stuff. You can get all this stuff without having any stuff. And that’s the key point that I care about, without any miracles.

Now, I want to spend the last two minutes just mentioning some things that I think Dr. Craig will talk about, having listened to him. Now, in fact, this—you can’t see it very well—this is something he showed—and he may show again, he showed in Brisbane. It’s something like he likes to do, sort of like a syllogism, some logical argument which makes it appear necessary to have God. And he said, well, every existing thing that has an explanation, has an explanation of its existence, O.K. And then he said if the universe has an explanation of its existence that explanation is God, and the universe is existing, and therefore the explanation of the existence of the universe must be God. Boy, that’s ironclad. Is it?

Well, you know, the key point is here [Krauss points to the screen]. You’ve got to accept, when you have these syllogisms, you have to accept that this is true, and this is just a random statement: That if the universe has an explanation the explanation is God. Well, great, but that sort of assumes the answer before you ask the question.

Syllogisms are very dangerous. Here’s an example: All mammal—if you make the wrong logical statement at the beginning you can get wrong results:

1. All mammals exhibit homosexual behavior.


2. William Lane Craig is a mammal.


3. Therefore, William Lane Craig exhibits homosexual behavior.

Now that isn’t true! Well, as far as I know. But the point is, you can get that if you, if you just blindly accept the assumptions at the beginning. And those assumptions are the ones I don’t want you to blindly accept.

Now, we’ll—I’ll probably zip through this because I think William is going to talk about the Kalam, maybe, and Islamic wisdom. Get it, Islamic wisdom? I had this exact same debate with an Islamic fundamentalist who used exactly the same arguments to prove that the Qur'an was absolutely true that, that William will do in this case. But again, the arguments are not—the statements are—none of which are true, and I, I won’t go through them because we’ll have a chance to talk about them. But none of those statements are true in, in modern physics, and therefore, the argument is irrelevant.

Now it is true that the Bible said the universe had a beginning well before science did. Great! But so did everything else. So did the Norse creation myths and the Rig Veda. And the Bible got it wrong! They do the creation in the wrong order. So, in fact, as, as St. Augustine would remind—I’m sure Dr. Craig—the Bible isn’t a scientific document. And therefore, to argue that it got it right—well, you know, every creation myth indicated there was a creation. It’s a natural thing. And I won’t even go into Lemaître.

I’m going to try to end in one minute with the, with another statement that Dr. Craig has made because for Dr. Craig the beginning of the universe is very important because if it had a beginning he believes it must have come from God. And he quotes a theorem due, due to a few friends of mine that basically says the universe, if it’s expanding now as, as we measure it, had to have a beginning. And he argues that that’s, that’s irreconcilable with anything else. And I—as we argued in Brisbane, I said that’s not true. And he said, no, Alex Vilenkin, one of the authors, has recently shown it’s true. So I wrote Alex, who’s a good friend of mine, and he just emailed me. And he said, “Any theorem is only as good as its assumptions.” There’s a loophole for a contraction prior to expansion, and, “there’s no such thing as absolute certainty in science . . . Note for example that the BGV theorem uses the classical picture of spacetime.” In the case of quantum mechanics, it’s out the window. And at the beginning of the universe that’s when quantum mechanics matters.

So, the last thing that is often used is the question of fine-tuning: The universe appears to be fine-tuned for life. Well that’s an old argument. You should have heard it before. Life appeared to be fine-tuned for life. Every form of life appeared to be fine-tuned for the environment in which it lived, and that’s why God existed. But we now know that is not the case because Darwin told us, you know what, natural selection produces that kind of possibility in the form of life. Well, if there are many different universes we would be amazed to find ourselves living in a universe in which we couldn’t live. That would be worth having a discussion on stage about. O.K.? So the fact that—if there are many different universes—the fact that we happen to be fine-tuned to the universe we live in is not too surprising. But in fact it’s worse because, just like evolution, the fine-tuning is miserable. I get backaches because I am not designed to sit at a computer. And in fact the fine-tuning could be much better than it is; life could be much more prevalent in the universe. So this fine-tuning argument is garbage.

And I think I will conclude with that, and just say, what we mean by something and nothing has completely changed. And that’s the important point. And that change is not a bad thing—it’s called learning. And the important question, I would argue, is not the question we’re talking about, “Why is there something rather than nothing?” but rather, “How did the universe evolve, and how—what, what’s going to happen? How can we find out?” And the way we can find out is by asking the universe questions and not making it up.

Thank you.

Dr. Craig - Presentation

Craig: Well, thank you very much! It is a delight to be here. And I also want to begin by thanking the City Bible Forum for putting on this extraordinary series of three dialogues between Dr. Krauss and myself. And I want to thank Lawrence Krauss for his participation in these dialogues.

The great German philosopher and scientist Gottfried Wilhelm Leibniz famously wrote, “The first question which should rightly be asked is: Why is there something rather than nothing?” Before we can even begin to address Leibniz’s question it’s important that we clarify the concepts involved.

The word nothing is a term of universal negation. It means not anything. So, for example, if I say, “I had nothing for lunch today,” what I mean is that I didn’t have anything for lunch today. If you read in an account of World War II that “nothing stopped the German advance from sweeping across Belgium,” what it means is that the German advance was not stopped by anything. If a theologian tells you that “God has created the universe out of nothing,” he means that God’s creation of the universe was not out of anything. The word nothing, to repeat, is simply a term of universal negation, meaning not anything.

There’s a whole series of similar words in English that involve universal negation: nobody means not anybody, none means not one, nowhere means not anywhere, no place means not in any place.

Now because the word nothing is grammatically a pronoun, we can use it as the subject or direct object of a sentence. By taking these words, not as terms of universal negation, but as words referring to something, you can generate all sorts of funny situations. If you say, “I saw nobody in the hall,” the wiseacre says, “Yeah, he’s been hanging around there a lot lately!” If you say, “I had nothing for lunch today,” he says, “Really? How did it taste?”

These sorts of puns are as old as literature itself. Do you remember the scene in Homer’s Odyssey, where Odysseus introduces himself to the Cyclops as “No man” or “Nobody?” One night Odysseus puts out the Cyclops’ eye. His fellow Cyclopses hear him screaming and yell to him, “What’s the matter with you, making so much noise so that we can’t sleep?” The Cyclops answers, “Nobody is killing me! Nobody is killing me!” They reply, “If nobody is attacking you, then you must be sick, and there’s nothing we can do about it!”

In Euripides’ version of the story, he composes a sort of Abbott and Costello “Who’s on first?” routine:

Leader: “Why are you crying out, Cyclops?”

Cyclops: “Nobody has undone me!”

Leader: “Then there is no one hurting you after all.”

Cyclops: “Nobody is blinding me!”

Leader: “Then you’re not blind.”

Cyclops: “As blind as you!”

Leader: “How could nobody have made you blind?”

Cyclops: “You’re mocking me! But where is this Nobody?”

Leader: “Nowhere, Cyclops!”

The use of these words like nothing, nobody, no one, as terms referring to something, is a joke.

How astonishing, then, to find that some contemporary popularizers of science, whose mother tongue is English, have used these terms precisely as substantive terms of reference. They’ve told us with a straight face, for example, that

“There are a variety of forms of nothing . . . and they all have physical definitions.” [2]

“The laws of quantum mechanics tell us that nothing is unstable.” [3]

“70% [of] the dominant stuff in the universe is nothing.” [4]

“There's nothing there, but it has energy.” [5]

“Nothing weighs something.” [6]

“Nothing is almost everything.” [7]

All of these claims take the word “nothing” to be a substantive term referring to something, for example, the quantum vacuum or quantum mechanical systems. These are physical realities and therefore clearly something. To call these realities “nothing” is at best misleading, bound to mislead and confuse laypeople, and at worst a deliberate misrepresentation of science. Such statements do not even begin to address, much less answer, Leibniz’s question as to why there is something rather than nothing.

In his review of Dr. Krauss’ book A Universe from Nothing, David Albert, an eminent philosopher of quantum physics, explains with respect to Dr. Krauss’ first kind of nothing:

“Vacuum states are particular arrangements of elementary physical stuff. . . . The fact that some arrangements of fields happen to correspond to the existence of particles and some don’t is not a whit more mysterious than the fact that some of the possible arrangements of my fingers happen to correspond to the existence of a fist and some don’t. And the fact that particles can pop in and out of existence, over time, as those fields rearrange themselves, is not a whit more mysterious than the fact that fists can pop in and out of existence, over time, as my fingers rearrange themselves. And none of these poppings . . . amount to anything even remotely in the neighborhood of a creation from nothing. . . .” [8]

He concludes, “Krauss is dead wrong and his religious and philosophical critics are absolutely right.” [9]

Now I think that Dr. Krauss really knows he’s not talking about nothing. He just pretends to be talking about nothing. In a dialogue at the Australian National University he candidly admitted that the question “Why is there something rather than nothing?” sounds like “a religious question,” but—and I quote— “I use it to sneak in modern cosmology,” [10] which is what he really wants to talk about. This is most unfortunate. Modern cosmology is fascinating enough in its own right that we don’t need to sneak it in by having it masquerade as an answer to a philosophical question like Leibniz’s. The cosmological theories to which Dr. Krauss refers have exactly zero relevance to Leibniz’s question. As Christopher Isham, Britain’s leading quantum cosmologist, has written, “The one question that even a very ambitious creation theorist cannot (or, perhaps, should not) address is: ‘Why is there anything at all?’” [11] I propose that henceforth we simply avoid the troublesome word “nothing” and focus on this question: Why does anything at all exist?

Leibniz came to the conclusion that the answer is to be found in God, Who exists necessarily and is the explanation why anything else exists. We can put Leibniz’s thinking into the form of a simple argument. So, premise (1):

1. Every existing thing has an explanation of its existence (either in the necessity of its own nature or in an external cause).

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

3. The universe exists.

Now what follows logically from these premises? From premises (1) and (3), it follows:

4. Therefore, the universe has an explanation of its existence.

And from (2) and (4) the conclusion logically follows:

5. Therefore, the explanation of the universe is God.

Now this is a logically airtight argument. It is not guilty of the equivocal fallacy that Dr. Krauss’ mammalian argument is guilty of. That is to say, if the three premises are true, then the conclusion is unavoidable. So if the atheist wants to reject the conclusion he has to say that one of the three premises is false.

But which one will he reject? Premise (3) is undeniable for any sincere seeker after truth. Obviously the universe exists! So the atheist is going to have to deny either premise (1) or (2), if he wants to be an atheist and remain rational. So the whole question comes down to this: Are premises (1) and (2) more plausibly true or false? Well, let’s look at them.

According to premise (1) there are two kinds of things: things which exist necessarily and things which exist contingently. Let me explain.

(a) Necessary: Things which exist necessarily exist by a necessity of their own nature. It’s impossible for them not to exist. Examples? Many mathematicians think that numbers, sets, and other mathematical objects exist in this way.

(b) Contingent: By contrast, things that are contingent do not exist necessarily. They exist because something else has caused them. Examples? Familiar physical objects like people, planets, and galaxies belong in this category.

So what shall we say about premise (1)? Well, if you reflect on it, premise (1) seems very plausibly true. Imagine that you were hiking through the outback and came across a translucent ball lying on the ground. You would naturally wonder how it came to be there. If one of your mates said to you, “It just exists inexplicably. Forget about it!” you’d either think that he was crazy or else he just wanted you to keep moving. No one would take seriously the suggestion that the ball just exists there with literally no explanation. Now suppose you increase the size of the ball in this story so that it’s the size of a car. That wouldn’t do anything to remove or provide [the need] for an explanation of its existence. Suppose it were the size of a house, same problem. Suppose it were the size of a planet, same problem. Suppose it were the size of the entire universe, same problem. Merely increasing the size of the object does nothing to provide or remove the need for an explanation of its existence. Something has to explain why it exists.

So it seems to me that premise (1) is more plausibly true than false.

So, what about premise (2), if the universe has an explanation of its existence, that explanation is God? Is it more plausibly true than false? Now at first blush this premise might strike us as controversial. But in fact atheists typically agree with premise (2). For what does the atheist typically say in response to Leibniz’s argument? The atheist typically asserts the following:

A. If atheism is true, the universe has no explanation of its existence.

But this is logically equivalent to:

B. If the universe has an explanation of its existence, then atheism is not true.

And notice that (B) is virtually synonymous with premise (2)! So when the atheist says that, given atheism, the universe has no explanation, he is implicitly admitting premise (2) that if the universe does have an explanation, then God exists.

Besides that, premise (2) is very plausible in its own right. For think of what the universe is: all of physical reality, including all matter and energy. It follows that if the universe has a cause of its existence, that cause must be a non-physical, immaterial being beyond space and time. Now only two sorts of things could fit that description: either an abstract object (like a number) or else an unembodied mind (or person). But abstract objects can’t cause anything. That’s part of what it means to be abstract. The number 7, for example, has no effect upon anything. So it follows that the cause of the universe must be a transcendent Mind. And this is what the theist typically means by God.

Thus, premise (2) also seems to be plausibly true.

Given the truth of the two premises—or three premises the conclusion logically follows: God is the explanation of the existence of the universe. Moreover, the argument implies that God is an uncaused, unembodied Mind who transcends the physical universe and even space and time themselves and who exists necessarily. We’re not talking about some ill-conceived Flying Spaghetti Monster but a being with specifiable attributes. This conclusion is staggering.

I hope you begin to grasp the power of Leibniz’s argument. If successful, it proves the existence of a necessary, uncaused, timeless, spaceless, immaterial, personal Creator of the universe. And He is the answer to the question of why anything at all exists.

Krauss: Boy, that is really you.

Moderator: Thank you! Whew, I don’t know if you feel as overwhelmed as I do, but where to begin? It seems that we must begin with terms. How can we have a dialogue about “nothing” if we simply do not agree on what it is? Lawrence?

Krauss: Well, I, I . . .

Moderator: And may I call you by your first names—


Moderator: —since we are in Australia,—

Krauss: Yes.

Moderator: —that’s the convention here—

Krauss: Yeah.

Moderator: —even though we are—

Krauss: No, no. Absolutely.

Moderator: —all from North America—

Krauss: Yeah, Yeah. No, no.

Moderator: —originally.

Krauss: And, and I appreciate you calling me Lawrence because we’re both from Canada so you don’t call me Larry.

Moderator: Yes, that’s right, he is a fellow Torontonian.

Moderated Dialogue - Q&A

Krauss: Well, I agree, and, and . . . and I tried, with that little video, I tried to be quite clear about what I mean. But in some sense I don’t think there’s a big difference. “Nothing,” in this case, is non-existence. The question is: Did the universe go from non-existing to existing? If it—it’s quite plausible that it did. It’s not required, by the way, it could have been eternal. It certainly could be eternal given the laws of physics. But as I said to—and, and William just told me that I could call him Bill so I am going to do so without any disrespect, O.K.?

Craig: Right!

Krauss: As Bill said in, in, in Brisbane, as I told him, I bet that the universe did have a beginning. That doesn’t bother me. In fact, I think that it’s more likely than not, although not required. But that means it did not exist. Now, did anything else exist? Maybe. But our universe didn’t. Everything we see, everything we touch, the space that we live in, and the laws the we—that govern us didn’t exist, and then did. Now, the problem with definitions, though, is that—it’s when you have modern physics certain ideas that for which there’s words, classical jargon, don’t mean the same thing. For example, if time begins, if time begins at the Big Bang, how do you discuss cause and effect? Those—so, so words begin to fail you—as T. S. Elliot would have said. And, and so, but I think the idea is, I, I’m arguing exactly the same thing as Bill is in some sense: non-existence.

Moderator: Lawrence, if, if, if all the materials or elements are present for life to exist, that is, that you detect in the universe, that of course doesn’t make them cohere into life. So how would you explain how such elements become life, in the same way that words in the dictionary do not become an essay or a poem?

Krauss: That’s, that’s the beauty—that’s what I do. That’s why I do science—because it’s so remarkable. It’s so much more remarkable than saying, “Let there be light!” It’s so much more remarkable to see how you can begin with a universe with no matter or radiation, create matter and radiation; understand the growth of fluctuations; understand how stars form; understand how planets form; understand how organic materials form in, in bulk, in supernova explosions from stars; understand the amazing processes that happen in the earth; and understand of course the most remarkable aspect, that complex organic materials seem to become—able to become self-ordered, and from a very simple self-reproducing object that appears to take energy from its environment, using natural selection, you can create everything. This illusion of design is probably the biggest obstacle—that when you see something it looks like it’s designed. And I often—and I have pictures of, you know, what would look like beautiful Christmas ornaments, but of course they’re snowflakes. Geodesic domes look like they’re designed, but Carbon sixty—soot—has the most beautiful geodesic dome. So, you have to be very careful when you look at something and say, “Ah ha, it’s designed!”, because most often it’s just an accident.

Moderator: Well, Bill, should God be subject to scientific or philosophical arguments, when to do so would make God vulnerable to the disproofs of new science?

Craig: Oh, of course! Now God isn’t subject to scientific investigation because science is the study of the physical natural realm, and so science doesn’t have at its disposal the methods to do this kind of metaphysical work. That’s why the name of that discipline is Meta physics

Moderator: Metaphysics.

Craig: —it’s beyond physics.

Moderator: And yet . . .

Craig: But now, I, I’d like to respond to what Dr. Krauss just said a moment ago about the beginning of the universe.

Krauss: You can call me Lawrence, Bill.

Craig: Lawrence, all right! Leibniz’s argument doesn’t presuppose that the universe had a beginning. It’s very important to understand that Leibniz’s argument applies equally if the universe is eternal—beginningless and endless. In fact, Leibniz actually uses the example of a series of geometry books which have been copied from one another from eternity, and he says that still wouldn't explain why geometry books exist at all and why they’re being copied. So we can still ask, “Why is there an eternal universe rather than nothing?”

But secondly, Lawrence, I have heard you in your YouTube videos, and elsewhere, make a number of times this claim that anything that begins to exist comes—goes from non-existence to existence and in that sense comes from nothing. And I think that’s a misconception. Take yourself. You didn’t exist prior to your conception, but that doesn’t mean that in beginning to exist you came from nothing.—

Krauss: Absolutely.

Craig: —There was a sperm and an egg that brought you into existence. That was a cause. So for something to come from nothing would mean that it comes into being without any sort of cause. That’s the way we’re using the term.

Krauss: O.K., well, I think, I think there is a really important point there, and it’s one of the reasons why that Kalam argument is so nonsensical. Because it says that everything that begins to exist has a cause, O.K. Well, that statement you have to parse a little more carefully, but classically nothing begins to exist. Classically, everything, you know, radiation, matter, does not spontaneously come into existence, classically. So, from that argument, that claim is completely unobserved because, as you point out, everything that you see coming into existence, including me, came from raw materials—

Craig: Yes.

Krauss: —that preexisted—

Craig: But surely—

Krauss: —so nothing begins to exist.

Craig: Surely you believe that you began to exist?

Krauss: Well, but the point is—you just said, I exist from preexisting materials—

Craig: Yes, I said they were causes of your existence.

Krauss: —and that’s what happens. But in quantum mechanics often things can come into existence spontaneously.

Craig: Well, that, that’s a different question.

Krauss: For example, let’s, let’s—here’s a good example, you seem to have problems with the creation of the universe, so let’s talk about the light that’s bombarding us—

Craig: Well, wait a minute. You’re changing the subject here.

Krauss: Well, I think I’m, I’m trying to make a point.

Craig: Well, but you’re changing—

Krauss: Let me, let me finish my sentence, if you think it’s irrelevant then just say—

Craig: All right.

Krauss: —it’s irrelevant, O.K.?

Craig: Yes.

Krauss: Good. And we know what your answer is going to be. But, so take a, so take a photon, take the light that is bombarding us so that I cannot see the audience. O.K., what was the cause of the photon that, that is hitting your eye? What’s the cause? There’s no physical cause; it was emitted spontaneously. You can’t say that there was that—you cannot say that that photon, which was emitted by an electron, which changed energy levels in [the] atom, had a cause; it just randomly did it. In fact, there’s some probability it might take ten to the ten to the tenth years to do it. It happened to happen now, and we can argue about probabilities, but in quantum mechanics the idea of, of cause in that sense is very different. That’s O.K. that it’s different, but it means these classical arguments of Leibniz, who didn’t know about quantum mechanics, are irrelevant.

Craig: Now wait—that, that was irrelevant—that comment that you just made! You were saying, before you went on this digression, that anything that begins to exist comes into being from nothing. And I was suggesting that that’s misconceived because things that begin to exist, like yourself, have causes. So they don’t come from nothing. Beginning to exist—x begins to exist if x exists at t, some time t, and there is no time t´ earlier than t at which x exists. And things like yourself—

Krauss: So what’s the cause of the photon?

Moderator: Bill, can I—can you finish your thought, and I’d like to ask you a question?

Craig: All right. Actually, I don’t want to rehash the Brisbane debate.—

Moderator: Yes, O.K.

Craig: —We, we had an opportunity there to talk about the Kalam argument and fine-tuning. Tonight is a different subject, which is Leibniz’s argument. And on Leibniz’s argument there’s no presupposition that the universe began to exist, nor is there a sort of claim that the universe is not eternal. So this is a quite different question.

Krauss: But there is that second . . .

Moderator: May I ask a question here. If it is clear to you that the universe has a cause, why should that cause necessarily be God? And is it because you—

Craig: Yes.

Moderator: —already believe in God’s existence or because you define God to be anything that is outside the observable universe?

Craig: That was premise (2) in, in the argument, as I stated it. And remember that I gave two defenses for thinking that if the universe has an explanation that explanation is God. The first one is that it’s logically equivalent to what atheists typically say in response to Leibniz. Atheists typically say that the universe just exists and that’s all. It’s a brute fact—

Krauss: No, I—look—I mean, it’s—look, I’m—you might call me an atheist, I don’t label myself, but I certainly never say that. You are confusing explanation and purpose.—

Craig: Oh no, no—no, not at all!

Krauss: —Those are two very different things. We—one of the reasons I am a scientist, one of the reasons I do what I do, is I want to find out the explanations. I want to ask questions and find out what—is, is there an explanation of how our universe came into existence?

Craig: Right.

Krauss: And that’s—and I, and I, and I’m agnostic about the answer.

Craig: Yeah, I think you concede, from what I can understand, premise (1). But it’s not about purpose, Lawrence. We’re, we’re talking here about explanations. And these could be causal.—

Krauss: So why God, why God?

Craig: —There’s nothing to do with teleology.

Krauss: That’s the most ridiculous thing I’ve ever heard!

Craig: Well, that’s premise (2). That was premise (2), and, again, as I said, premise (2) is logically equivalent to what most atheists say in response to Leibniz. But then the second argument for premise (2) was that the only two candidates that I can possibly think of which—for being an immaterial, spaceless, timeless, transcendent thing would be either an abstract object or an unembodied mind—

Krauss: But why does it have—I mean, I mean—

Craig: —or consciousness, and abstract objects—

Krauss: That, that—all that does is show the limitation of your thinking.

Craig: Well, you—

Krauss: I mean—and that’s what, that’s what’s, that’s what’s—but that’s what’s great about science. It forces you to change your thinking. There’s lots—

Craig: I’m ready to change.

Krauss: —of things—Sorry, listen, the point is, why does it have to be immaterial. Why—I mean—

Craig: Oh, that’s easy to answer!

Krauss: —and so to say, the only thing I can think of—the point is, I’ll give you one very clear example, is in the case of the multiverse. Our universe could exist—

Craig: Yes.

Krauss: —could come into existence, in the concept—in the context of something that’s far greater, far bigger—

Craig: Sure.

Krauss: —in which universes may be even be created now, and it’s physical. There’s no, there’s no, there’s no transcendent—

Craig: Right.

Krauss: —mind. It’s like saying—

Craig: Right.

Krauss: —that life exists, and therefore there has to be a creator. Well, there doesn’t!

Craig: No, no, it’s much more subtle than that. When—the way I defined universe in my opening remarks was as all of physical reality. And that would include not only our universe but any wider encompassing multiverse.—

Krauss: What do you mean by—wait, hold on, but now you’re being vague and now you’re being, look, we have to be more careful. What do you mean by “all of physical reality?” Do you mean all of space and time? Is that—do you mean all of space and time? I want to know what you mean, because as a physicist it makes a difference.

Craig: Yeah, yeah—yeah well, I mean any sort of spacetime reality or, or something that’s matter and energy.

Krauss: All of space and time in which events happen. Maybe a good way to say it would be: all of space and time in which events can happen. But there could be a lot more than that. My point is: that’s not everything. All of space and time in which events can happen is just our universe.

Craig: No, no, it’s not, because you can have an encompassing spacetime. It’s larger—

Krauss: No, no,—

Moderator: Lawrence.

Krauss: —because it may have a very different time, it may not involve events. It certainly doesn't involve anything that happens in our universe.—

Craig: No.

Krauss: —So if you say physical reality, do you mean space and time? If you mean space and time, then we live in a four-dimensional spatial universe, but there could be other universes in which even the concept—

Moderator: Lawrence.

Krauss: —of classical space doesn’t exist.

Craig: Not classical space. But look, Leibniz’s question can easily be reposed: “Why does the multiverse exist rather than nothing?” It’s—and then you’re onto the same argument.

Krauss: You could do that, but multiverse could be eternal.

Craig: Again, Leibniz’s argument doesn’t presuppose a beginning.

Krauss: But it’s a great question, but it’s not the question we’re asking, which is: Why does our universe exist? And that has a simple answer.

Craig: No, no—no, it’s—

Moderator: Well, can I ask—

Krauss: O.K.

Moderator: —a question because it’s becoming pretty difficult to get in-between here.

Krauss: Well, actually, you can ask questions. But I think we want to hear between the two of us.

Moderator: Of course! Now today many of you would have read an interesting news item in the press that John Billingham had died. He was the man who had established the SETI project—scouring the skies, the universes, for extraterrestrial life. Now, Lawrence, you have said that you are painfully aware that humans need to know they are unique, their, their earth is unique, their universe is unique. But what evidence is there that we are not? And does the failure of the SETI project to find any sign of extraterrestrial life even remotely akin to ours a further confirmation that we are unique?

Krauss: Well, it’s a good question. My—the simple answer is one that Carl Sagan gave, the absence of evidence is not evidence of absence. And the point is that, that we live in a really big universe. And, in fact, there’s nothing unique about our location in the universe. There’s nothing unique, in fact, about the, the conditions that led to life on earth. Organic materials exist in profusion in space. Not only have we discovered the basis of amino acids in comets, but we’ve discovered complex, in fact, complex peptides. And, and so, organic materials exist everywhere, water exists everywhere, sunlight exists everywhere, [and] as far as we can tell those are the conditions that produced life on earth. Now, we are looking—

Moderator: But none of them have cohered in—into life.

Krauss: No, hold on, hold on! But, but—what was that?

Moderator: But none of them have cohered into anything that resembles life.

Krauss: Well, we know—one thing we do know is in our solar system, on the surface of planets there, right now, and, and, and moons, the conditions don’t exist for life like us to exist. So we’re looking. But the point is: it’s a very difficult task. It’s a big universe. One thing we have discovered, which increases our, our optimism that there may be life elsewhere, is the fact that, as many of us astrophysicists have said, all stars have solar systems around them. If you make a star on a computer you tend to get an accretion disk, and you make a solar system. We’ve discovered not only do solar systems exist, planets exist that we never thought were possible: rocky planets on the outside of solar systems, gas giants on the inside. The universe always surprises us every time we open a new window. So there’s probably a hundred billion solar systems in, in, in our galaxy alone.

But let me give you a brief example of why it’s so difficult. How would I know life existed on earth, O.K.—intelligent life? Let’s say I lived on some other star—now our sun is only 4.5 billion years old. The galaxy is twelve - thirteen billion years old. So most stars are older. I could’ve looked at our sun for the last five billion years—if I was in an advanced civilization—only during the last fifty years could I have gotten evidence that life existed by listening to I Love Lucy or Q and A, or whatever the heck it is. And, and—but then I’d have to know the right channel to listen to. So even if I knew exactly where to look, and what channel to listen to, I have a one in fifty million chance of finding the right time on earth to find intelligent life. It’s a hard process. But hard things are what science is all about. So we, undaunted, we look. We don’t know the answer. But many of us would suspect there’s life elsewhere, and where—and in fact maybe even life elsewhere, microbial life, on Mars, or in the oceans of Europa. And we’ll just—and the point is we don’t know, and that’s why we keep looking.

Moderator: Bill, now this, this sort of vision is, is rather infinite, is it not? I mean, are—you, you have said, well, Lawrence you, you’ve said that physicists are uncomfortable with infinity. But Bill you seem to be more comfortable with it. Is, is that right? Or—I’m trying to figure out how an infinite universe, which you have said is meaningless, no—

Craig: Oh?

Moderator: —you, you have said an infinite universe is meaningless. Have I got that wrong?

Craig: I, I don’t think so, no.

Moderator: No? No. O.K.

Craig: But in any case, this, this question—

Moderator: How does, may I just ask you—

Krauss: He said that infinity isn’t physical. So he did say that.

Moderator: —how does your interest in immortality connect or relate to a notion of an infinite universe?

Craig: Well, I—do we really want to talk about this? I mean, it’s off topic. We’re, we’re supposed to be talking about why is there something rather than nothing. But—

Moderator: Than nothing.

Krauss: No, no, I think, I think it’s not off topic because the universe could be infinite in temporal extent—

Craig: Yes, but Leibniz’s argument is independent—

Krauss: —or infinite in a special extent. So if we’re—if we want to talk about how the universe came into being, we might want to know whether it’s infinite or not, for example.

Craig: No, no, we don’t! No, no, as I said, Lawrence, Leibniz’s argument is very clearly independent of the question of whether the universe had a beginning or an end. You can ask: Why does an eternal universe exist?

Now to answer the question, I would distinguish between—well not just I but mathematicians—between an actual infinite and a potential infinite. An actual infinite is a collection which has a definite and discrete number of finite members which is equal in number to the natural numbers.

Krauss: No, no, that’s one kind of infinity, there are non-countable infinities.

Craig: Yes, that’s À0. That’s the lowest—

Krauss: That’s the low—there are non-countable infinities, like irrational numbers—O.K. O.K.

Craig: Of course, there are. There are non-denumerable infinities. I’m talking about the lowest denumerable infinite.

A potential infinite, by contrast, is a limit concept. Something can approach infinity as a limit but never get there. For example, you can keep dividing this finite distance in half further and further and further, and infinity can serve as a limit to that process. And I would say with respect to immortality that we will live forever in the sense of a potential infinite. The number of years of our existence will always be finite but growing toward infinity as a limit. They would grow without—

Krauss: How—you always say these things, but how the hell do you know it?

Craig: Well, that’s a different debate, Lawrence.

Krauss: I mean, what, what, this [unintel] a statement that has no basis in empirical fact. It’s what you’d like to be, and that I find offensive.

Craig: No, I mean—come on, you, you’ve not—obviously not read my books!

Krauss: Well, how do you know what immortality is?

Craig: Well.

Krauss: It may seem like this talk is taking forever, but other than that?

Craig: Now look, you are really trying to chase red herrings here to get away from the topic.

Krauss: Well, you just said it, Bill. You just said, “I know that immortality is not infinite.” Well, that’s great, I’m glad you know it?

Craig: No, she asked—she asked me what was my conception.

Krauss: Well, you said it. O.K.

Moderator: O.K., let me ask you something, Lawrence. This is another ridiculous question. Given that everything that science discovers is perceived and mapped out by the human brain, what do you think is greater: the brain, the human brain, or the universe that—or the universe that it recognizes?

Krauss: Well, first of all, with all due respect, I don’t understand what you mean by greater. Is that a value judgment?

Moderator: Significant—yes! What, I mean, what is more necessary?

Krauss: Well, I—it appears, it certainly appears to me that the universe’s existence is necessary for my existence. That seems to be the case. Although, who knows? I mean it could be that, that you—that I, that I could spontaneously pop into existence without a universe. And maybe I have. But . . . but, but so—but greater is the kind of thing that, you know, it’s just—it’s, it’s an irrelevant question. The point is, the human brain is remarkably complex, and we don’t understand it. The universe is remarkably beautiful, and we don’t fully understand it—which is the joy, the joy of not understanding, is what makes life worth living. Not the joy of certainty that immortality is potentially finite, or that certainty that there will be seventy-two virgins in heaven if you blow up the World Trade Center or something. I mean, that kind of nonsense is, is what just stifles, it seems to me, what makes being human worth being human. It’s, it’s the uncertainty, it’s the mystery, it’s not knowing, and that effort to understand this incredibly complex thing, which we—I admit we may never understand. I mean, some people think that, you know, physicists are the most obnoxious of all scientists, that’s true, well, I’d say that—

Craig: No, just, just you!

Krauss: Just me, O.K.

Moderator: Do you . . .

Krauss: And I may be the most—no, I can say from, from experience that I’m not the most obnoxious physicist I know, but anyway—although I’m up there. But, but (now you’ve confused me), but the, the point is that, that we don’t, we don’t claim to know everything. That’s, that’s the whole point. We don’t claim certainty. And that’s great.

Moderator: Well, do you claim certainty, [Dr. Craig]?

Craig: No! No! This is—

Moderator: I, I, I don’t get that impression in your work.

Krauss: Are you certain that God exists?

Craig: No!

Krauss: Good.

Craig: I mean, this is so crazy, Lawrence. You do this all the time in contrasting science and religion with these false dichotomies.

Krauss: Well, you demonstrate them.

Craig: I think not! I mean—I, I would say that science and theology are very similar in that they’re both on a quest for understanding. Christian faith—

Krauss: Well let me . . .

Craig: —is not a brain-dead faith. It is a rational, inquiring faith. St. Anselm had a slogan: “fides quaerens intellectum,” which means “faith seeking understanding.” And so, like science, which we as Christians celebrate, theology has also embarked on the process—

Krauss: Give me one example. I’m going to ask you a question that I have asked other theologians—

Craig: Yeah.

Krauss: I don’t think I have ever asked you this question, maybe I have—

Craig: No, but you’ve asked others.

Krauss: You know the question—

Craig: Yes.

Krauss: —you’ve prepared the answer? Good! Good, because I’d like to learn about this.

Craig: All right.

Krauss: I’ve asked a lot of theologians what contributions to human knowledge has theology provided in the last, say, three hundred years? Give me one example. The answer I always get is, “What do you mean by knowledge?” Now if I ask a biologist or a chemist or a historian, I get a different answer.

Craig: Theology is the queen of the sciences. The proper object of theology is God. Theology is the study of God. It gives us the—

Krauss: But didn’t you say that God isn’t subject to science? So in what—didn’t you say God—didn’t you say science can’t—God is not subject to science, didn’t you say God is outside science?

Craig: Yes.

Krauss: So for that case—

Moderator: Lawrence, let—

Krauss: —if theology is the study of God, then how can it be a science?

Craig: Well—

Moderator: Lawrence, let him answer the question, please!

Krauss: Well . . .

Moderator: Because I—we’re not, we’re not—we’re not actually going to get anywhere if you’re constantly talking over Bill. Please!

Krauss: O.K.

Craig: My—

Krauss: Actually, actually, I actually do think we’ll get somewhere. We’ll get rational definitions.

Craig: O.K.

Moderator: Bill, if you can respond—

Craig: All right, I’ll try to be succinct.

Moderator: —and then, and then we will go to the questions from the floor.

Craig: My theology students from Germany often wrestled with the question: Is theology a Wissenschaft? That is to say—that’s the word for science in German. But what they meant by science was in the classical sense: scientia, knowledge. And certainly theology is a source of knowledge. It gives us knowledge of God, his existence and nature, what he requires of us, what our moral obligations are to him, how to find eternal life and forgiveness of sins. These—you may not be interested in, in this, but that doesn’t do anything to deny the fact that, that theology is a scientia, it is a body of truth, it is a body of knowledge, just as much as science is scientia about the natural world.

Krauss: But, but—

Moderator: And it might—and, and I might also say that in, in the way that Bill is defining knowledge in this way, you also have redefined something like “nothing” in your way.—

Craig: Right!

Moderator: —So—

Krauss: Well, let me, let me say that there’s a difference. And, and the fact is that, if theology gives us knowledge of God, how come different theologies give you different knowledge? I mean, science—physics that’s done in, in the Islamic world is the same as physics that’s done in this world. That, that, you know, balls fall, Newton’s laws work. But, in fact, theologians of different religions come up with—

Craig: Sure.

Krauss: —completely inconsistent views of what God is, and what eternity is.—

Craig: But, but you—

Krauss: —And so if it is really knowledge it’s very particular to where you grew, grew up.

Craig: But you celebrate uncertainty, right?

Krauss: Yes.

Moderator: [Laughter] O.K. Well . . .

Craig: Yeah, so, so what what’s the, why—just as quantum physicists have at least ten different physical interpretations—

Krauss: But they’re not inconsistent.

Craig: —of the equations of quantum mechanics.

Krauss: They’re not—the difference is, if two scientific ideas are inconsistent, one is right and one is wrong, or they’re both wrong.—

Craig: Yeah.

Krauss: —They’re not both right.

Craig: Oh, oh, but Lawrence, I am not a relativist! I am not a pluralist. I, I think that the same holds for theology. In fact I am, I am gratified—

Krauss: And you think that Christianity is right, and Islam is wrong?

Craig: —I am gratified to hear you affirming the law of contradiction here and affirming the laws of logic.

Krauss: O.K., so Islam is wrong?

Craig: I do believe that Islam is not fully true; that there are elements of Islam that are false. For example, its view of Jesus of Nazareth, I think, is, is patently wrong. According to—

Krauss: And, and Zeus is wrong?

Craig: —Yes, but let me—

Krauss: So you’re an atheist about all those other religions?

Moderator: Well—

Craig: No.

Krauss: O.K., O.K.

Craig: Could I just finish my statement about where I disagree with Islam because this is important, I think. There’re probably many Muslims here tonight. According to the Qur’an, Jesus was never crucified. And that is a view which is rejected by every historian of Jesus—

Krauss: Hold up, every theologian! I’m not sure every historian.

Craig: No, every—no—there is no historian—

Moderator: We will—

Krauss: No, no, that is not true! I—we’ve had this discussion.

Craig: The one fact—the one indisputable fact about Jesus of Nazareth was that he was crucified; he died by crucifixion. So here—

Krauss: If he existed.

Craig: —so here we have in the Qur’an, a, a book written six hundred years after the event by a man who had no firsthand sources with regard to this event, and, and he denies the crucifixion of Jesus. And I think that if for that reason it’s not the correct view.

Moderator: O.K. At this point—

Krauss: As, as, as opposed to the Bible, which was written maybe fifty or one hundred years after the fact.

Moderator: Thank you, Lawrence and Bill! At this point we really must go to questions from the audience otherwise none of you will get a chance. And since I’ve had to trash most of my questions at this point because this has really been a very dynamic argument!

Krauss: But I think that’s, that’s O.K. that we argue. I think that’s O.K.

Moderator: But, yeah, Yes. Can I just remind you once again to send your short questions to Twitter. It’s up there on the screen: #LUNQA, and the SMS to the number there on the screen. I already have some here, which have already been sent up. So, the first one is: “Dr. Craig, why is God exempt from your definition of something? That is, why can God exist alongside nothing?”

Craig: Right! Can we bring up slide thirty-nine, please? Notice premise (1) says, “Every existing thing has an explanation of its existence.” I don’t exempt God. Leibniz’s Principle of Sufficient Reason, which comes to expression in premise (1), does not exempt God. Rather, it would say that God is a metaphysically necessary being which exists by a necessity of its own nature, similar to the way mathematical objects exist, if you’re a Platonist. So I am not exempting God from this principle.

Moderator: Good! O.K., nice and straight! Lawrence, “by appealing to an infinite number of universes, aren’t you just requiring the existence of an infinite just as theists do?”

Krauss: Well, well, first of all I’m not appealing to an infinite number of universes. And the answer is, I don’t know. There may be an infinite number of universes, and I, you know, if that’s the case I’ll live with it. The, the—space itself may be infinite in spatial extent, and as I said, the universe may—although I would doubt it—well in the future, all the evidence says that the future of our universe will be infinite in temporal extent. So I don’t have—so infinities are, may or may not exist. The question is to find out why. And so I don’t appeal to anything. There may be an infinite number of universes. There may be 10500 universes, as some versions of string theory suggest, although, again, that calculation is very tenuous. 10500 is enough to, to give you, to give you what we would call the landscape of, of, of natural selection, of . . . of life, if you, if you accept the anthropic argument which may or may not be true. So you don’t need an infinite number of things to—just like you don’t need an infinite distribution of a population to talk about the natural selection in life. You just need a very—you need very long time and a very large number of, of members of a species in order to get genetic diversity in order to get evolution. And so you don’t have to appeal to infinity. But the answer is: I don’t know.

Moderator: Dr. Craig, “to prove that Leibniz’s argument—proof that Leibniz’s argument is false if God, in premise (2), was changed to Elmo.

Craig: The problem is I don’t know who Elmo is. Now, if Elmo is,—

Krauss: What?

Craig: —Well—

Krauss: You know who Elmo is.

Craig: —you mean the Sesame Street character?

Krauss: Yeah, yeah.

Craig: Well, obviously, Elmo is himself a contingent being, if that’s who you mean! I was thinking perhaps they’re just calling God “Elmo,” which is just God by another name. But if you mean the sock puppet, obviously that isn’t the reason why everything exists rather than nothing. That, that’s a silly question.

Krauss: I don’t . . .

Moderator: O.K. Lawrence, can you please clarify how it is possible to exit the universe.

Krauss: To exit the universe? Well . . . I could think of a lot of answers. But, look . . . from a physical perspective we are tied to our universe. It could be that there are, that there are—it could be—and one of the conventional ideas in modern physics is that perhaps one of the four forces of nature, gravity, actually does exit our universe, namely our four-dimensional spacetime; it may leak into extra dimensions. That’s an argument, which, by the way, I think is probably wrong, but it’s certainly got a lot of interest among physicists right now. So there may be forces that actually do exit our universe. Our—in those theories the particles that make us up, quarks and leptons, are confined to the four-dimensional membrane that makes us up. Now—but things can cease to exist in the sense that both me and Bill will cease to exist when we die, in the sense of, of our consciousness, just as my Mac, which is certainly more conscious than the PC that’s running that thing, is—will cease to exist when I, when, you know, if I break it. But that’s no problem. I don’t have any problem with that.

Moderator: Dr. Craig, if someone were—if a Christian were to exit the universe, where would he go, or she go?

Craig: If, if a Christian were to exit the universe? Well, since I believe in the reality of the soul distinct from the body, I think that it, it would be possible for the soul to exit the universe, that is to say, it would no longer exist in this four-dimensional spacetime, and in that case it wouldn’t be any where at all. To ask, “Where is it?” is to assume that it’s still in space. It would simply exist, but it wouldn’t exist in space. It, it wouldn’t be part of this four-dimensional spacetime.

Krauss: Can I ask a question?

Moderator: Yes.

Krauss: I mean we’re supposed to have a discussion? I waited for you to finish. I tried to do that.

Craig: You did!

Krauss: Yeah, O.K. Sometimes you make me so mad I can’t wait. But anyway . . . what’s the evidence for the existence of a soul separate from the body? What’s your evidence for that? Why,—

Craig: Yeah.

Krauss: —why do you have that belief is what I want to know?

Craig: O.K.

Krauss: And I mean that honestly, why you have that belief? I’m not trying to—

Craig: Right, right! I would say that there are a number of features that are best explained by some kind of dualism-interactionism. One of the most persuasive to me—and I’ll try to be very succinct—is intentionality: the idea of aboutness, or of something. For example, I can think of my wife or about my summer vacation. No physical object has this kind of intentionality. The desk, or the boards, or the chair, or a glob of tissue like the brain, isn’t about something. Only mental states, or states of consciousness, have intentionality. And this seems to me to be an undeniable feature of human experience and phenomena, that we have these states of intentionality. And I think it—they’re best explained by saying that there is a mind, a mental substance.—

Krauss: A consciousness, I mean there we agree. I think I agree.

Craig: —Yeah, a consciousness.

Krauss: The only evidence I can see of intentionality right now is conscious minds. But all you’ve done is demonstrate the existence of consciousness, not a soul.

Craig: Well, no, you have to have some thing that exhibits this property of intentionality—it can’t be the brain.

Krauss: Consciousness.

Craig: Well, but then, what is consciousness? Consciousness would be a thinking thing, a thinking substance, or mental substance.

Krauss: It’s, it’s—absolutely, yes, but that’s not a soul.

Craig: Well I, I would call a mind a soul.

Krauss: What about when—O.K., it’d be an interesting thing, when, when, when in one hundred years when computers are self-aware, will they have souls?

Craig: No. I don’t think that’s a good example. I don’t think that a computer will ever have intentionality—

Krauss: But again—well . . .

Craig: —because a physical object isn’t about something else. So—

Krauss: Aren’t we physical objects?

Craig: Excuse me?

Krauss: Are we not—I mean, it’s a key point, what seems to me, what you’ve done, and fairly clearly, is demonstrate that consciousness is a real example—is one of the only examples, and I agree with you—of intentionality. But all you’ve demonstrated is that a complex physical system can be conscious and be self-aware and have intentionality. But I—but there’s nothing non-physical about it. You’ve not demonstrated that any of that is non-physical. I mean, you may believe it, and I accept that belief. But there is no evidence for it.

Craig: Well, again, I don’t see how views—I think what you are espousing is sort of a non-reductive physicalism, where you have these mysterious mental properties of the brain. But the brain doesn’t seem to have these sorts of mental properties. And this view is also incompatible—

Krauss: But, you’re thinking right now. You are demonstrating—

Craig: Yeah.

Krauss: —I mean, sometimes.

Craig: Well but I—I would, I would say that the, the soul or the mind uses the brain as an instrument of thought. This is what Sir John Eccles, the Nobel Prize winning neurologist, put it in his—

Krauss: —Which shows that the Nobel Prize doesn’t mean anything.

Moderator: O.K. Lawrence, Lawrence . . .

Krauss: I mean, no, I mean, we—there are no authorities, that’s the great thing. I can say nonsense, as you’ve just argued, Sir John Eccles can. The key point is I, I accept that you think that there’s this thing that guides humans. And that’s fine that you accept that, but, but accept that there is no empirical evidence for it. Do you agree?

Craig: Empirical evidence? Well, I think there is the evidence of introspection. I sense my intentional states. There couldn’t be—could there be?—there couldn’t be empirical evidence.

Krauss: Have you ever fooled—have you ever fooled yourself about, about your senses?

Craig: Yes, but, you see, that’s the thing about intentionality, is that it can’t be—

Krauss: [To Dr. Kohn] I’m sorry to frustrate you, but I think this discussion is useful.

Moderator: Can I, can I ask you another question?

Krauss: O.K.

Craig: Well, let me just say one thing!

Moderator: Yes, alright.

Craig: Intentionality can’t be illusory because to have an illusion is itself an intentional state—it’s an illusion of something.

Krauss: Well, as, as Oliver Sachs has said, hallucinations are real to those people that have them.

Moderator: Those are certainly true.

Krauss: O.K. They are every bit as real as everything that happens to us in this room, if you have a hallucination.

Moderator: And what about investigating a largely unobservable flat universe?

Krauss: What?

Moderator: I mean, the flat universe, as you have written in your book, is, is, is largely unobservable.—

Krauss: No, no, I’m sorry!

Moderator: —I mean it’s just a very small part of it.

Krauss: That’s the whole point. I only talked about what we can observe. We observed—we measure the flatness of the universe. We don’t measure something that we can’t observe. We measure a triangle that’s very large and measure that the sum of the angles are one hundred eighty degrees—that’s measurement. The observable universe is flat. What happens beyond the observable universe, who knows?

Moderator: O.K. “If space and time originated from the Big Bang, how could a—how could a quantum tunneling even have occurred before there was spacetime?” This is to you, [Lawrence], obviously!

Krauss: Well, look, I mean, obviously it’s a complex thing. But the first point is, let me give two versions of an answer—it’s a complex thing.

Moderator: I, I confess . . .

Krauss: But let me, let me just basically say—general relativity, the beauty of general relativity, is that it’s a theory of space and time. It shows that what we experience as gravity is really a manifestation of the fact that spacetime is curved. It’s an amazing, amazing revelation that happens to be true, O.K. Now, the real problem in physics is that this theory, general relativity, this force of gravity, is different than the other three forces in nature, which have very good quantum mechanical definitions. Now quantum mechanics tells us that the variables of that system fluctuate, they, they pop in and out of existence, they change, over small scales they do lots of things that classically isn’t impossible. If you had a quantum theory of gravity, then the fundamental parameters of, of that quantum theory would be space and time. And they would fluctuate widely, pop in and out of existence, and do all of the other things that other, that, that, are associated with other quantum theories. So, if you had a quantum theory of gravity and we don’t—some people think that string theory is a good approximation—it would of necessity have that property by merging quantum mechanics with, with, with space and time. So it would be a natural, in fact it, it’d be impossible for it not to happen, that spaces, that universes, spacetimes, pop into existence. That can happen. But, let me say, having said that, there’s a problem with the words, not the mathematics, and that is, that since space and time are affected by matter, once, once you get to a point where, where you, where your, where the quantum mechanics and gravity becomes important, space and time themselves may not be appropriate variables. Time itself may arise out of the Big Bang. There may be no time before the Big Bang in which case the question “What happened before?” is simply not a good question.

Moderator: Lawrence, there are a lot of problems with words here tonight. And I would suggest that most of the people in the audience are not scientists at your level, and therefore, even by reading your lucid book, your, your latest one, A Universe From Nothing, they would, perforce, have to take so much of your science on trust, on faith, on belief—

Krauss: No, they shouldn’t.

Moderator: —because they really couldn’t assess it.—

Krauss: Well no. You . . .

Moderator: —They don’t have the reserves of knowledge to do so. So my question is,—

Krauss: Well . . . we all do that.

Moderator: —is anyone who is reading your book and accepting your explanations, any wiser, any brighter, any more intellectually fit, than someone who, who, who believes in a faith, or believes the doctrinal arguments for faith?

Krauss: Look, look—hold on, first of all—

Moderator: And, and . . .

Krauss: —people shouldn’t take my book on faith; they shouldn’t take anything on faith. They should say, “This interests me. I’d like to learn more about it. I’d like to see if other people are contradicting—I’d like to learn about it.” If they’re interested enough, they’ll, they’ll do that. That’s the point of writing a book. I—you, you can’t—I can’t explain everything but I can motivate people to learn. But I don’t want to suggest—there are many, there are many scientists who are religious.

Moderator: Indeed, there are.

Krauss: You know, when I go on FOX News or other brain-dead things in the United States, one of the only times I’ve—probably the most useful thing I can say, for example, is that you don’t have to be an atheist to believe in evolution. And that has huge impact because there are kids, unfortunately, who are taught in my country, go to church every week and are told you have to be an atheist to accept evolution. So, of course, they won’t accept evolution because they, they have faith. There are well-known scientists that are people of faith—

Craig: Or they lose their faith!

Krauss: —there are well-known scientists that are people of faith. And so being—having faith, all it represents—to me, all it represents is you can have completely—that human beings are wired to have completely inconsistent notions at the same time. But, you know, that’s an argument that I can make. But there’re scientists who are religious and, and yet they are very good scientists. So, you know, to argue that somehow believing things means you can’t do science is, is clearly wrong. What you do, though, when you go into the laboratory, is you become an atheist. You assume no one is twiddling the dials when you’re doing the experiment. O.K. And then you come out afterwards and, and you’re not. So I think that that’s where the scientists—they go in and assume that . . . that no one is twiddling the dials in their experiment.

Craig: Could I make a practical suggestion that I think Lawrence would agree with? For—because this is a question that really is hard: Whom do you believe?—especially the layperson reading popular science, or popular philosophy for that matter, or theology because, as you said, there’s so much disagreement. One thing that can help, and that I would encourage folks to do, is when you read a book, read book reviews of the book by other scholars. And that can often help to shed some light on the controversial issues.

Krauss: I, I, think what they should do is actually search the literature.

Craig: Yes. But remember, a layperson—

Krauss: Because, you know, I don’t know how many books are properly reviewed but, you know, the review could be nonsense, just like a movie review. So what you can do is—what you can do is question. Forget the reviews! The point is, you keep going to authorities—

Craig: Well, but—no, no, no!

Krauss: —hold on, does this seem reasonable? If it—you know, there’s a—one of my favorite quotes is from the former publisher of The New York Times. He said, “I like to keep an open mind, but not so open that my brains fall out.” And the point is, if some argument seems crazy, it might be, and so don’t accept it. Ask the questions and see what it implies. And also ask yourself the question: is this person selling me something to make money? Are they, are they, are they doing this—are they selling me something, literally, to make money, or are they selling me something not to make money? That’s an important difference . . . O.K.

Moderator: Just going down the list of possible questions here . . . “How did God decide to create the world if there was no time to make any decisions?”

Craig: Yeah, that’s a really interesting question!

Moderator: I must confess that, that’s original.

Craig: Deciding isn’t a necessarily temporal activity. One can have an intention that isn’t the result of a previous state of indecision. So I would say that God exists timelessly with the intention that a physical world exist, and then there is an exercise of his causal power that brings the universe into existence. But we shouldn’t think of God as existing, twiddling his thumbs from eternity, and then deciding to make a universe. That’s not only incompatible with his timelessness, it’s incompatible with his omniscience because God doesn’t need to reason from premises to conclusion; He already knows the conclusion. So I would say that God simply has a timeless, free intention of the will to do something, and then there’s an exercise of causal power that brings the universe into being.

Moderator: May I ask you a question that came from someone in the audience? “How do you know that other gods of humanity: Zeus, Zarathustra, Lord Shiva, or Krishna, etc., are not true, and have you falsified all these gods before believing that your particular view of the Christian God is true? And if so, isn’t that counter to the requirement of faith?”

Craig: It’s not counter to the requirements of faith to say that you need to investigate the alternatives, and look at the arguments and evidence. So I would say that in deciding whether—which—or if any God at all exists, you need to look at the arguments and the evidence and to search honestly with a humble and open heart and mind. Now that’s not incompatible with faith. Faith is believing what you have good reason to think is true. Faith is trusting in that which you have good reason to think is true. And that’s not incompatible with argument and evidence.

Moderator: And yet your own discovery of God from the depths of despair brought you joy when you were young, and that was surely something that came to you outside of an investigation.

Craig: Well, yes, that’s certainly very true, Rachael.

Moderator: [It] came in an experience.

Craig: I was not raised in a Christian home or even a church-going family. But I became a Christian my junior year in high school when a girl who sat in front of me in my German class, who was a radiant Christian, shared with me the story of God’s love in Christ. And I had never heard this before. And it overwhelmed me because the idea that the God of the universe could love me, that worm down there on that speck of dust called planet Earth, just overwhelmed me. So I went home that night, and I found a New Testament, and I began to read it. And I was captivated by the person of Jesus of Nazareth. There was a, an authenticity about this man’s life that I had never encountered before and a ring of truth about his words. And I went through a period of about six months wrestling with these issues until finally, yes, I came to the point of decision and did place my faith in him and, and became a Christian. And my life has never been the same since.

Moderator: Lawrence, you became a cosmologist, having been a physicist, because you wanted to be the first person to discover the end of the universe. Now that strikes me as a kind of an apocalyptic intention. What, what was it that made you—

Krauss: You have to understand when I’m joking, first! But I said I wanted to be the first one to know how the universe would end, and it’s just a matter of wanting to learn things. I became a physicist—I became a scientist, because my mother wanted me to become a doctor and unfortunately told me doctors were scientists, and it took me a while to discover they weren’t. But, I, I became a scientist, actually, there are lots of reasons, actually, and part of it is philosophy. I read a great book on physics and philosophy by Sir James Jeans when I was in high school, but before that I read about Galileo. It seemed to me the sexiest, most exciting, most exciting human activity, is to try to explore the unknown. And, I mean, I find Dr. Craig’s honest discussion of his road to Christianity, and his discussion of God, to me represents, while, while I accept it—and I don’t mean to demean—it’s going to sound like I am going to demean it—but I accept it as very real and means a lot to you, and so that’s fine. It, it’s what gets you through life, and that’s, that’s fine. But the point is, it gave you what you wanted and needed, and that’s wonderful. But the universe doesn’t give a damn what you want and need. And sometimes, it, you know, you just have to say, If I really want to understand the universe, I have to understand that my wants and needs, as much as I want someone to look after me and some universal love, and, it may not be there. I have to accept that possibility. And moreover,—

Moderator: But . . .

Krauss: —your discussion of God and, and when he decided is the perfect example of the problem. The problem is: (1) it’s, it’s in my mind intellectually lazy. This is—I can’t—this complex universe, I can’t understand, so I’m going to make a—I’m going to imagine a more complex thing, which I won’t give any