Tag Archives: KCA

William Lane Craig lectures on naturalism at the University of St. Andrews

Lets take a closer look at a puzzle
Lets take a closer look at a puzzle

Note: even if you have heard Dr. Craig’s arguments before, I recommend jumping to the 48 minutes of Q&A time, which starts 72 minutes in.

About Dr. William Lane Craig:

William Lane Craig (born August 23, 1949) is an American analytic philosopher, philosophical theologian, and Christian apologist. He is known for his work on the philosophy of time and the philosophy of religion, specifically the existence of God and the defense of Christian theism. He has authored or edited over 30 books including The Kalam Cosmological Argument (1979), Theism, Atheism and Big Bang Cosmology(co-authored with Quentin Smith, 1993), Time and Eternity: Exploring God’s Relationship to Time (2001), and Einstein, Relativity and Absolute Simultaneity (co-edited with Quentin Smith, 2007).

Craig received a Bachelor of Arts degree in communications from Wheaton College, Illinois, in 1971 and two summa cum laudemaster’s degrees from Trinity Evangelical Divinity School in Deerfield, Illinois, in 1975, in philosophy of religion and ecclesiastical history. He earned a Ph.D. in philosophy under John Hick at the University of Birmingham, England in 1977 and a Th.D. underWolfhart Pannenberg at the University of Munich, Germany in 1984.

Dr. Craig was in Scotland to lecture at a physics conference, but a local church organized this public lecture at the University of St. Andrews.

Here is the full lecture with Q&A: (2 hours)


  • Naturalism defined: the physical world (matter, space and time) is all that exists
  • Dr. Craig will present 7 reasons why naturalism is false
  • 1) the contingency argument
  • 2) the kalam cosmological argument
  • 3) the fine-tuning of the universe for intelligent life
  • 4) the moral argument
  • 5) the ontological argument
  • 6) the resurrection of Jesus
  • 7) religious experience

Dr. Craig does mention an 8th argument early in the Q&A – the argument from the non-physicality of mental states (substance dualism), which is an argument that I find convincing, because a materialist conception of mind is not compatible with rationality, consciousness and moral agency.

Questions and Answers

He gets a couple of questions on the moral argument early on – one of them tries to put forward an evolutionary explanation for “moral” behaviors. There’s another question the definition of naturalism. There is a bonehead question about the non-existence of Jesus based on a Youtube movie he saw – which Craig responds to with agnostic historian Bart Ehrman’s book on that topic. There’s a question about God as the ground for morality – does morality come from his will or nature.

Then there is a question about the multiverse, which came up at the physics conference Dr. Craig attended the day before. There is a good question about the Big Bang theory and the initial singularity at time t=0. Another good question about transfinite arithmetic, cardinality and set theory. One questioner asks about the resurrection argument. The questioner asks if we can use the origin of the disciples belief as an argument when other religions have people who are willing to die for their claims. One of the questioners asks about whether the laws of nature break down at 10^-43 after the beginning of the universe. There is a question about the religious experience argument, and Craig has the opportunity to give his testimony.

I thought that the questions from the Scottish students and faculty were a lot more thoughtful and respectful than at American colleges and universities. Highly recommended.

Alexander Vilenkin: “All the evidence we have says that the universe had a beginning”

I’ve decided to explain why physicists believe that there was a creation event in this post. That is to say, I’ve decided to let famous cosmologist Alexander Vilenkin do it.

From Uncommon Descent.


Did the cosmos have a beginning? The Big Bang theory seems to suggest it did, but in recent decades, cosmologists have concocted elaborate theories – for example, an eternally inflating universe or a cyclic universe – which claim to avoid the need for a beginning of the cosmos. Now it appears that the universe really had a beginning after all, even if it wasn’t necessarily the Big Bang.

At a meeting of scientists – titled “State of the Universe” – convened last week at Cambridge University to honor Stephen Hawking’s 70th birthday, cosmologist Alexander Vilenkin of Tufts University in Boston presented evidence that the universe is not eternal after all, leaving scientists at a loss to explain how the cosmos got started without a supernatural creator. The meeting was reported in New Scientist magazine (Why physicists can’t avoid a creation event, 11 January 2012).

[…]In his presentation, Professor Vilenkin discussed three theories which claim to avoid the need for a beginning of the cosmos.

The three theories are chaotic inflationary model, the oscillating model and quantum gravity model. Regular readers will know that those have all been addressed in William Lane Craig’s peer-reviewed paper that evaluates alternatives to the standard Big Bang cosmology.

But let’s see what Vilenkin said.


One popular theory is eternal inflation. Most readers will be familiar with the theory of inflation, which says that the universe increased in volume by a factor of at least 10^78 in its very early stages (from 10^−36 seconds after the Big Bang to sometime between 10^−33 and 10^−32 seconds), before settling into the slower rate of expansion that we see today. The theory of eternal inflation goes further, and holds that the universe is constantly giving birth to smaller “bubble” universes within an ever-expanding multiverse. Each bubble universe undergoes its own initial period of inflation. In some versions of the theory, the bubbles go both backwards and forwards in time, allowing the possibility of an infinite past. Trouble is, the value of one particular cosmic parameter rules out that possibility:

But in 2003, a team including Vilenkin and Guth considered what eternal inflation would mean for the Hubble constant, which describes mathematically the expansion of the universe. They found that the equations didn’t work (Physical Review Letters, DOI: 10.1103/physrevlett.90.151301). “You can’t construct a space-time with this property,” says Vilenkin. It turns out that the constant has a lower limit that prevents inflation in both time directions. “It can’t possibly be eternal in the past,” says Vilenkin. “There must be some kind of boundary.”

A second option explored by Vilenkin was that of a cyclic universe, where the universe goes through an infinite series of big bangs and crunches, with no specific beginning. It was even claimed that a cyclic universe could explain the low observed value of the cosmological constant. But as Vilenkin found, there’s a problem if you look at the disorder in the universe:

Disorder increases with time. So following each cycle, the universe must get more and more disordered. But if there has already been an infinite number of cycles, the universe we inhabit now should be in a state of maximum disorder. Such a universe would be uniformly lukewarm and featureless, and definitely lacking such complicated beings as stars, planets and physicists – nothing like the one we see around us.

One way around that is to propose that the universe just gets bigger with every cycle. Then the amount of disorder per volume doesn’t increase, so needn’t reach the maximum. But Vilenkin found that this scenario falls prey to the same mathematical argument as eternal inflation: if your universe keeps getting bigger, it must have started somewhere.

However, Vilenkin’s options were not exhausted yet. There was another possibility: that the universe had sprung from an eternal cosmic egg:

Vilenkin’s final strike is an attack on a third, lesser-known proposal that the cosmos existed eternally in a static state called the cosmic egg. This finally “cracked” to create the big bang, leading to the expanding universe we see today. Late last year Vilenkin and graduate student Audrey Mithani showed that the egg could not have existed forever after all, as quantum instabilities would force it to collapse after a finite amount of time (arxiv.org/abs/1110.4096). If it cracked instead, leading to the big bang, then this must have happened before it collapsed – and therefore also after a finite amount of time.

“This is also not a good candidate for a beginningless universe,” Vilenkin concludes.

So at the end of the day, what is Vilenkin’s verdict?

“All the evidence we have says that the universe had a beginning.”

This is consistent with the Borde-Guth-Vilenkin Theorem, which I blogged about before, and which William Lane Craig leveraged to his advantage in his debate with Peter Millican.

The Borde-Guth-Vilenkin (BGV) proof shows that every universe that expands must have a space-time boundary in the past. That means that no expanding universe, no matter what the model, can be eternal into the past. No one denies the expansion of space in our universe, and so we are left with a cosmic beginning. Even speculative alternative cosmologies do not escape the need for a beginning.


If the universe came into being out of nothing, which seems to be the case from science, then the universe has a cause. Things do not pop into being, uncaused, out of nothing. The cause of the universe must be transcendent and supernatural. It must be uncaused, because there cannot be an infinite regress of causes. It must be eternal, because it created time. It must be non-physical, because it created space. There are only two possibilities for such a cause. It could be an abstract object or an agent. Abstract objects cannot cause effects. Therefore, the cause is an agent.

Now, let’s have a discussion about this science in our churches, and see if we can’t train Christians to engage with non-Christians about the evidence so that everyone accepts what science tells us about the origin of the universe.

The kalam cosmological argument defended in a peer-reviewed science journal

Here’s the peer-reviewed article. It appears in a scientific journal focused on astrophysics.

Here’s the abstract:

Both cosmology and philosophy trace their roots to the wonder felt by the ancient Greeks as they contemplated the universe. The ultimate question remains why the universe exists rather than nothing. This question led Leibniz to postulate the existence of a metaphysically necessary being, which he identified as God. Leibniz’s critics, however, disputed this identification, claiming that the space-time universe itself may be the metaphysically necessary being. The discovery during this century that the universe began to exist, however, calls into question the universe’s status as metaphysically necessary, since any necessary being must be eternal in its existence. Although various cosmogonic models claiming to avert the beginning of the universe predicted by the standard model have been and continue to be offered, no model involving an eternal universe has proved as plausible as the standard model. Unless we are to assert that the universe simply sprang into being uncaused out of nothing, we are thus led to Leibniz’s conclusion. Several objections to inferring a supernatural cause of the origin of the universe are considered and found to be unsound.

The whole text of the article is posted online here.

Here’s an excerpt in which the author, Dr. William Lane Craig, explains the Big Bang cosmology:

The monumental significance of the Friedman-Lemaitre model lay in its historization of the universe. As one commentator has remarked, up to this time the idea of the expansion of the universe “was absolutely beyond comprehension. Throughout all of human history the universe was regarded as fixed and immutable and the idea that it might actually be changing was inconceivable.”{8} But if the Friedman-Lemaitre model were correct, the universe could no longer be adequately treated as a static entity existing, in effect, timelessly. Rather the universe has a history, and time will not be matter of indifference for our investigation of the cosmos. In 1929 Edwin Hubble’s measurements of the red-shift in the optical spectra of light from distant galaxies,{9} which was taken to indicate a universal recessional motion of the light sources in the line of sight, provided a dramatic verification of the Friedman-Lemaitre model. Incredibly, what Hubble had discovered was the isotropic expansion of the universe predicted by Friedman and Lemaitre. It marked a veritable turning point in the history of science. “Of all the great predictions that science has ever made over the centuries,” exclaims John Wheeler, “was there ever one greater than this, to predict, and predict correctly, and predict against all expectation a phenomenon so fantastic as the expansion of the universe?”{10}

As a GTR-based theory, the Friedman-Lemaitre model does not describe the expansion of the material content of the universe into a pre-existing, empty, Newtonian space, but rather the expansion of space itself. This has the astonishing implication that as one reverses the expansion and extrapolates back in time, space-time curvature becomes progressively greater until one finally arrives at a singular state at which space-time curvature becomes infinite. This state therefore constitutes an edge or boundary to space-time itself. P. C. W. Davies comments,

An initial cosmological singularity . . . forms a past temporal extremity to the universe. We cannot continue physical reasoning, or even the concept of spacetime, through such an extremity. . . . On this view the big bang represents the creation event; the creation not only of all the matter and energy in the universe, but also of spacetime itself.{11}

The popular expression “Big Bang,” originally a derisive term coined by Fred Hoyle to characterize the beginning of the universe predicted by the Friedman-Lemaitre model, is thus potentially misleading, since the expansion cannot be visualized from the outside (there being no “outside,” just as there is no “before” with respect to the Big Bang).{12}

The standard Big Bang model thus describes a universe which is not eternal in the past, but which came into being a finite time ago. Moreover,–and this deserves underscoring–the origin it posits is an absolute origin ex nihilo. For not only all matter and energy, but space and time themselves come into being at the initial cosmological singularity. As Barrow and Tipler emphasize, “At this singularity, space and time came into existence; literally nothing existed before the singularity, so, if the Universe originated at such a singularity, we would truly have a creation ex nihilo.“{13}

[…]On such a model the universe originates ex nihilo in the sense that at the initial singularity it is true that There is no earlier space-time point or it is false that Something existed prior to the singularity.

Every theist should be able to understand and defend this argument. It is a scientific refutation of materialism, and it is supported by six lines of scientific evidence – all of which emerged as science has progressed.

Scientific evidence:

  1. Einstein’s theory of general relativity (GTR)
  2. the red-shifting of light from distant galaxies implies an expanding universe
  3. the cosmic background radiation (which also disproves the oscillating model of the universe)
  4. the second law of thermodynamics applied to star formation theory
  5. hydrogen-helium abundance predictions
  6. radioactive element abundance predictions

Those are the scientific discoveries that have led us to the beginning of the universe, which support’s Dr. Craig’s argument.

This is the kind of evidence I expect all Christian theists to be using when discussing the question of whether God exists. Scientific evidence. When talking to non-Christians, we first need to show that we understand science, because science is a reliable and respected way of getting knowledge about the universe. Non-Christians do not accept the Bible, but they do accept science, so we begin evangelism with science. Science (experimental, testable, repeatable science) should set limits on what anyone can believe – including non-Christians, who might otherwise not be inclined to listen to Bible verses and theology. Important: it’s not a good idea to discuss the resurrection of Jesus with a person who does not accept the scientific evidence for a Creator of the universe.

The Big Bang is not compatible with atheism

According to the Secular Humanist Manifesto, atheism is committed to an eternally existing universe, (See the first item: “Religious humanists regard the universe as self-existing and not created.”). If something non-material brought all existing matter into being, that would be a supernatural cause, and atheists deny that anything supernatural exists. The standard Big Bang theory requires that all the matter in the universe come into being out of nothing. This falsifies eternal models of the universe, which are required by the atheistic worldview.

William Lane Craig debates atheist Lawrence Krauss: Does God Exist?

British Spitfire and German Messerschmitt Me 109 locked in a dogfight
British Spitfire and German Messerschmitt Me 109 locked in a dogfight

Here is the video from the third debate from Dr. William Lane Craig’s speaking tour in Australia.


  • William Lane Craig (15 min)
  • Lawrence Krauss (15 min, but was actually 21:40)
  • Moderated discussion
  • Question and answer

Dr. Graham Oppy, the moderator, is a well-known atheist philosopher. He let Dr. Krauss speak for 21 minutes and 40 seconds, which is why my summary of Krauss is so long.

The video:


After careful consideration, I decided not to be snarky at all in this summary. What you read below is what happened. There may be some small mistakes, but I will fix those if people tell me about them. I also included some quotes and timestamps for the more striking things that Dr. Krauss said.

The debate itself starts at 4:50 with Dr. Craig’s opening speech. He does use slides to show the structure of his arguments.

Dr. Craig’s opening speech. (4:50)

  1. The kalam cosmological argument:
    • God is the best explanation of the origin of the universe
    • The Borde Guth Vilenkin theorem supports the absolute beginning of the universe
    • Even if our universe is part of a multiverse, the multiverse itself would have to have an absolute beginning
    • Speculative cosmologies try to challenge the Big Bang theory, but none of them – even if true – can establish that the past is eternal
    • Only two types of things could explain the origin of spece, time, matter and energy – either abstract objects or minds
    • Abstract objects do not cause effects, but minds do cause effects (we do it ourselves)
    • A mind is the best explanation for the origin of the universe
  2. The unreasonable effectiveness of mathematics:
    • The underlying structure of nature is mathematical – mathematics is applicable to nature
    • Mathematical objects can either be abstract objects or useful fiction
    • Either way, there is no reason to expect that nature should be linked to abstract objects or fictions
    • But a divine mind that wants humans to understand nature is a better explanation for what we see
  3. The cosmic fine-tuning for the existence of intelligent life
    • There are two kinds of finely-tuned initial conditions: 1) cosmological constants and 2) quantities
    • These constants and quantities have to be set within a narrow range in order to permit intelligent life
    • There are three explanations for this observation: law, chance or design
    • Law is rejected because they are put in at the beginning or matter – they don’t emerge from matter
    • Chance must be rejected, because they odds are just too long unless you appeal to a world-ensemble
    • We do not observe what the world ensemble hypothesis predicts that we should observe
    • Design is the best explanation for finely-tuned constants and quantities
  4. The existence of objective moral values and duties
    • Our experience of morality (values and duties) is that it is objectively real and incumbent on us
    • When someone goes into a classroom and shoots at innocent children, that is objectively wrong
    • On naturalism, moral values and moral duties do not exist – they are conventional and variable by time and place
    • The best explanation for the existence of objective moral values and duties is that God exists
  5. The historicity of the resurrection of Jesus
    • There are three widely-accepted facts that are best explained by the resurrection hypothesis
    • 1) the empty tomb, 2) the post-mortem appearances, 3) the early church’s belief in the resurrection
    • Naturalistic attempts to explain these 3 boilerplate facts fail
    • The best explanation of the 3 minimal facts is that God raised Jesus from the dead
  6. The immediate experience of God
    • Belief in God is a “properly basic” belief – rational even without arguments because of experience of God

Dr. Krauss’ opening speech. (21:12)

Slides: (1234567891011121314)

  1. Religious pluralism I
    • There have been lots of different gods created by people through history
    • We’ve gotten rid of all of them by understanding how the universe works by doing science
    • Religion is just stories, and the stories are inconsistent with how the universe works
  2. Progress of naturalistic science I
    • Newtonian physics refutes the idea that angels push planets around
    • Darwinian evolution refutes design arguments, including the one that Dr. Craig presented (24:10)
    • Biochemistry hasn’t explained how life originated, but we will have the solution soon
    • Physics shows us that matter can be created and destroyed without need a God
    • Physics shows us that universes can be created and destroyed “no problem”
  3. Religious pluralism II
    • Since we have been able to disprove all the gods we’ve invented, why hang on to the last one
    • It’s unlikely that the God that Dr. Craig presented exists, because we disproved all the others he didn’t present
  4. Hiddenness of God
    • There is a complete lack of evidence for the other 999 gods, so how likely is it that the God Dr. Craig presented exists
  5. Religious pluralism III
    • There are inconsistencies between various religions, so therefore there can be no religion that is right
  6. Progress of naturalistic science II
    • Peasants had a very low level of knowledge about the world and they believed in God
    • But our level of knowledge has increased over time, so we shouldn’t believe in God now
    • Peasants thought that the Earth orbited the Sun, but this is now known to be false
    • The Scriptures said that the Earth orbited the Sun, but now we know that’s false from science
  7. Christianity plagiarizes from other religions I
    • There is nothing new or special about Jesus
    • He’s just as unpleasant as all the other gods
    • Everything particular to Jesus occurs in other religions
  8. Catholics are inconsistent about what they believe
    • I’ll bet most Catholics don’t really believe in transubstantiation
    • I’ll bet most Catholics don’t really believe in the virgin birth
  9. The resurrection is copied from many other religions
    • Dionysus, Osiris, etc.
  10. There is no evidence for the resurrection
    • The stories about Jesus were written “decades or hundreds of years after the fact”
    • The stories are inconsistent with each other
    • Dr. Craig tells me that historical Jesus scholars all accept that the resurrection happened
    • That’s like saying that all alien abductions experts agree that alien abductions happened
    • It’s unreasonable to think that the resurrection happened because no one saw it happen
    • I accept that people reported on appearances, but hallucination theory can explain that
  11. The timeline for the creation and incarnation are all wrong
    • The creation, planet formation, hominids, incarnation, etc. all take place in the wrong times
    • If God knew what he was doing, he would done everything at better times to be more efficient
  12. David Hume’s argument against miracles is sound
    • Extraordinary claims require extraordinary evidence – nothing wrong with this argument
    • Miracles are really just coincidences
    • Catholic apparitions at Lourdes disprove the historical argument that Dr. Craig made for the resurrection
  13. God is petty and jealous
    • God shouldn’t demand that we trust him, esteem him and consider his character when we make decisions
    • The atoning death of Jesus for the sins of the world also makes no sense
  14. Belief is based on geography
    • What you believe is clearly correlated with where you are born
    • There is even an Islamic clone of Dr. Craig who “uses the exact same arguments” that he does to prove Islam
    • Belief in God is decreasing in the Internet-accessible world
  15. Science can develop morals without God
    • Reason is able to guide our actions to be moral
    • Morality evolves over time, so there is no objective morality
    • Catholicism teaches things that are immoral
    • Some things are prohibited by biological revulsion, such as incest
    • But if a brother and sister have sex using condoms “is that morally wrong? I can’t say it is frankly” (37:24)
  16. Dr. Craig is irrational
    • “I came here convinced based on my past interactions and his writing that Dr. Craig was a dishonest Charlatan”
    • “Any argument that validates God is reasonable to him”
    • “And any argument against it is not only unreasonable but wrong and worth distorting”
    • “Because it must be wrong – he’s decided the answer in advance”
  17. Dr. Craig is immoral
    • Dr. Craig thinks it is OK for God to command that Canaanite children are killed
    • “So in fact if they were Canaanite children in that schoolroom that he talked about then it would be OK”
    • It’s not reasonable to justify genocide in that way, but Dr. Craig is willing to go to those lengths
  18. The cause of the origin of the space time universe need not be God
    • Dr. Craig says that if there is an explanation for the origin or space, time, matter and energy it must be God
    • But it could just as easily be turtles or Zeus
  19. Dr. Craig misrepresents the Borde Guth Vilenkin theorem
    • Alexander Vilenkin wrote me an e-mail that says that the theorem doesn’t work in all cases
    • “Dr. Craig is so convinced that these arguments must be true that he won’t listen to the fact that they’re not”
  20. Darwinian evolution explains the fine-tuning
    • “Life was fine tuned – we got rid of it with Darwin”
    • Mutation and natural selection explain the cosmic fine-tuning argument that Dr. Craig presented
  21. Suboptimal design disproves the fine-tuning argument
    • “We get back aches” therefore “This argument that [the universe] is fine-tuned for life is nonsense”
  22. William Lane Craig can be proven to exhibit homosexual behavior using logical arguments
    • Look, you can construct arguments that are clearly wrong
    • Premise 1: “All mammals exhibit homosexual behavior”
    • Premise 2: “William Lane Craig is a mammal”
    • Seems to be saying that logical arguments can prove false things “it’s nonsense”
  23. Dr. Craig distorted a podcast that some group made on pain receptors
    • Dr. Craig’s faith is so strong that it causes him to distort what this group said

Discussion: (44:35)

I will not be summarizing everything that was said, just a few main points.

The segment from 52:18 to 57:12 about the Vilenkin e-mail on the BVG theorem is a must-see. Krauss is standing up and gesticulating while Craig is calmly trying to quote a paper by Vilenkin that shows that Krauss is misrepresenting Vilenkin. Krauss constantly interrupts him. After a while, when Craig exposes him as having misrepresented Vilenkin and gets him to admit that all current eternal models of the universe are probably wrong, he quietens down and can’t even look at Craig in the face.

Cosmological argument:

  • Craig: The e-mail says any universe that is expanding, on average, requires a beginning
  • Craig: There are two models – Aguirre & Gratton and Carroll & Chen – where there is a period of contraction before the expansion
  • Craig: The two models are the ones cited in the e-mail that Dr. Krauss showed
  • Craig: In the very paper by Vilenkin that I cited, he says that both of those models don’t work
  • Krauss: (agitated and interrupting) Vilenkin said that they have to make an assumption about entropy that they have no rationale for
  • (as Craig starts to talk Krauss makes an exaggerated, disrespectful gesture and sits down in a huff)
  • Craig: Yes, an unwarranted assumption means that they don’t have EVIDENCE for their theories being correct
  • Krauss: (agitated and interrupting) “All the evidence suggests that the universe had a beginning but WE DON’T KNOW!!!!!!!” (raising his voice)
  • Craig: I’m not saying that we know that the universe had a beginning with certainty
  • Craig: I am saying that the beginning of the universe is more probably true than false based on the evidence we have
  • Craig: And you  agree with me about that – you think the universe had a beginning
  • Krauss: (agitated and interrupting) (Unintelligible)
  • Moderator: One at a time
  • Craig: In your Vilenkin e-mail slide, at the end of the paragraph where the two models are mentioned that Vilenkin specifically shows…
  • (I am guessing that Craig is going to ask why so much of what Vilenkin wrote has been cut out of the e-mail that Krauss showed)
  • Krauss: (agitated and interrupting) Because it was technical…
  • Moderator: Lawrence! Hang on a sec!
  • Craig: He specifically shows that these models are not past eternal, and that they require a beginning just like the others…
  • Krauss: (agitated and interrupting) We can do the math if you want
  • Craig: Now wait. I couldn’t help notice that there on your slide there was a series of ellipsis points indicating missing text…
  • Krauss: (agitated and interrupting) “Yeah, because it was technical!”
  • Craig: “I wonder what you deleted from the original letter”
  • Krauss: (agitated and interrupting) “I just told you!”
  • Craig: “Now wait. Could it have been something like this:  (reads a quote from Vilenkin) ‘You can evade the theorem by postulating that the universe was contracting prior to some time. This sounds as if there is nothing wrong with having contraction prior to expansion. But the problem is that a contracting universe is highly unstable. Small perturbations would cause it to develop all sorts of messy singularities, so it would never make it to the expanding phase.’
  • Craig: “That’s Vilenkin.”
  • Krauss: “In this paper, that’s absolutely right”
  • Krauss: But it’s ok for theories to assume things that we know are wrong – they are still good theories – it’s unknown
  • (Craig turns away and looks through his papers)
  • Craig: “Isn’t it true that the only viable quantum gravity models on order today involve a beginning – have a finite past?”
  • Krauss: “No”
  • Craig: “Well, can you give us one then”
  • Krauss: (talks about a variety of possible eternal models) “In my experience in science, all of them are probably wrong”
  • Krauss: “You know most theories are wrong, which is why, you know, it’s hard”
  • Craig: “Right”

I noticed that a huge number of atheist web sites are taking the Vilenkin quote that Krauss used out of context, like this one and this one. There are probably a lot more of them like that, which I think is interesting. That’s why we have these debates, I guess. To set the record straight about who accuses people of being dishonest, and who is actually dishonest.


  • Krauss tried to argue that he had explained the fine-tuning with the Higgs particle, but Dr. Craig said that only applied to the cosmological constant, not all the other examples of fine-tuning. Krauss said that it wasn’t impressive that this universe permitted life and that “It would have been much more surprising if we evolved in a universe in which we couldn’t live”. Krauss argued the fine-tuning was only for “Life like us”. But Dr. Craig explained that the fine-tuning is what allows us to have the basics of any kind of life, like slow-burning stars, chemical diversity, etc. – things that are required for basic minimal life functions in any living system. Craig said that he was working with the current physical laws of this universe (F = ma, etc.) and that he was looking at what changed if we changed those even slightly. Krauss tried to say that if he changed things like the mass of particles then the strength of forces would change. (But the forces aren’t laws!) Krauss argued that the cosmological constant would be even better for life if it was zero, and Craig said that the life permitting range did include zero, but that the range of life-permitting values was narrow.

Jesus’ existence:

  • Craig reponded to the mystery religions charge, the charge that the evidence for the minimal facts is too late/too weak, the charge that grief visions explained the evidence better, and Hume’s argument against miracles. Craig brought up the early creed from 1 Cor 15:3-7 and explained to Krauss that it was 5 years after the events, and that Jewish standards of oral transmission were strong enough to ensure that the creed was reliable, and most of the eyewitnesses would still have been alive.

Audience Q and A: (1:21:09)

The first topic is the grounding of morality. Krauss agrees that there is no objective morality and no objective moral oughts. He also said that that standards of behavior are arbitrary, and that they change over time and they are adopted for promoting social order. Dr. Craig pressed the point that science itself would collapse without ethical values. It assumes them, but cannot ground them.

The next topic was free will. Krauss is a determinist. Craig asked him how he could reconcile moral responsibility with determinism.

The next topic was the effectiveness of mathematics. Krauss didn’t have an explanation for it and didn’t think it needed one. Then they got into whether the Genesis has been verified by science and whether it is meant to be taken literally.

The next topic was whether philosophy makes any progress. Craig gave the example of verificationism being rejected as too narrow, and self-refuting. Krauss: “I’m going to come to the defense of philosophy for the first time”. Craig: “That’s amazing!” Krauss said that science provides new knowledge. Craig said there were some things that could be known apart from science.

Sean Carroll debates William Lane Craig on cosmology and God’s existence

British Spitfire and German Messerschmitt Me 109 locked in a dogfight
British Spitfire and German Messerschmitt Me 109 locked in a dogfight

Here’s the video of the debate:

Carroll was as good of a speaker as Craig in terms of style. Very easy to listen to, very quick on his feet, very civil. There was no clear winner on style.

It was difficult to assess the truth value of scientific points being made, especially for the layperson. I explained a few of them in my posts earlier this week, but I think laypeople might struggle with them if they are hearing about these things for the first time.

A couple of Craig’s slides: (click for larger images)

Slide 1 of 2:

Dr. Craig slide #1 of 2
Dr. Craig slide #1 of 2

Slide 2 of 2:

Dr. Craig slide #2 of 2
Dr. Craig slide #2 of 2

Quick summary: (this is not complete, because I couldn’t get everything they were saying noted)

Dr. Craig defended two arguments: 1) the kalam cosmological argument and the fine-tuning argument.

Dr. Craig supported the origin of the universe with 1) the expansion of the universe and 2) the second law of thermodynamics.

Dr. Craig said that the BGV theorem supports a beginning for the universe.

Dr. Craig said that the consensus of scientists did not accept Carroll’s naturalistic cosmology, quoting Stephen Hawking in support.

Dr. Craig said that multiverse models fall victim to the Boltzmann brain problem, where we should observe Boltzmann brains coming into existence and then phasing out again far more probably than embodied minds. But we observe embodied minds, and no Boltzmann brains.

Dr. Carroll said that science cannot study metaphysical questions.

Dr. Carroll said that science is about making models that may or may not be consistent with the experimental data.

Dr. Carroll said that the BGV theorem does not support a beginning for the universe.

Dr. Carroll proposed 17 alternative cosmologies, but did not provide a shred of scientific evidence for any of them, the way that Craig did for the standard model.

Dr. Carroll refuted Dr. Craig’s citation of Stephen Hawking, and Craig yielded the point.

Dr. Carroll speculated that science might progress to the point where the fine-tuning can be explained without an intelligent cause, and he gave an example of where that happened (inflation).

Dr. Craig argued that all 17 of the models suggested by Carroll either conflicted with evidence, had serious problems or did require a beginning.

Dr. Craig argued that Carroll’s own model required a beginning.

Dr. Craig argued that Carroll’s own model fell victim to the Boltzmann brain problem.

Dr. Craig argued that Carroll’s own model violated the second law of thermodynamics.

Dr. Craig re-stated his point that the baby universe spawning in Carroll’s model was speculative and incomplete, and cited Christopher Weaver’s work.

Dr. Carroll denied that things that pop into being out of nothing require a transcendent cause.

Dr. Carroll reiterated that science can only make naturalistic models, and that he did not have to answer questions about ultimate causes.

Dr. Carroll showed a photo of Alan Guth expressing his opinion that the universe is “probably” eternal. No evidence was given for this assertion.

Dr. Carroll said that the fine-tuning was not done in an optimal way, because one fine-tuned value was lower than it needed to be, and it should be exactly what it needed to be if God did it.

Dr. Carroll said that a finely-tuned universe is more probably in naturalism than in theism, because God can do anything he wants and doesn’t need a fine-tuned universe.

Dr. Carroll said he would stop defending his model now, and would instead defend Aguirre-Gratton.

Dr. Craig gave three reasons why the universe popping into being out of nothing requires a transcendent cause.

First, he said that nothing cannot cause anything to happen, because nothing is nothing.

Second, he said that if things pop into being out of nothing, then why don’t we see it happening all the time with other things.

Third, he said that we have no reason to dismiss the causal principle, especially when it is the basis of scientific inquiry and has been so fruitful in the progress of science.

Dr. Craig reiterated that baby universes in Carroll’s model would be dominated by Boltzmann brains, and we don’t observe that.

Dr. Craig said that even on the quantum gravity models that Carroll mentioned, there would still be a beginning.

Dr. Carroll said that Craig mustn’t say “popped into being” but instead that “there was a first moment of time”.

Dr. Carroll said that his model does indeed violate the second law of thermodynamics “YES!”.

At this point Carroll stopped talking about the topic of the debate and started expressing personal opinions about religion. It’s funny how often atheists do this in debates.

Dr. Carroll said that most theists don’t believe in God because of cosmology, but because of community and feelings.

Dr. Carroll said that science had learned a lot in the last 2000 years, so theism was false.

Dr. Carroll said that most philosophers don’t think that God exists, so theism was false.

Dr. Carroll said microscopes and telescopes were absent 2000 years ago, so theism was false.

Dr. Carroll said that religion should be about community and feelings, not about what is true.


My conclusion was that Carroll lost because he is just satisfied to throw theories out and not to argue that they are true by citing evidence. Carroll never seemed to be interested in finding out what is true, but instead he just wanted to tell a story that didn’t include God, and assert that by Occam’s Razor, his story was a better explanation. I am not impressed with theoretical speculations, although the layperson might be. I kept waiting for him to respond to Craig’s points about how his model was falsified by experimental evidence and observations, e.g. – the Boltzmann brains or the baby universe generation, and he never cited the evidence I wanted him to cite. Craig did have some evidence for his views, but he could have been stronger in making his case. He could have shown the e-mail from Vilenkin that stated that he had understood the BGV theorem, and was using it correctly, for example.

For me the winning side comes down to evidence. The standard model is the standard model because of scientific evidence. Until that evidence is overturned, then speculative models are of no interest to anyone who is evidence-driven. Speculations are not science. A philosophical presupposition of metaphysical naturalism is not science.

If you want to see a good lecture on scientific evidence related to cosmology, then there is the particle physicist Michael Strauss lecture on cosmology and fine-tuning at Stanford University and his more recent lecture at the University of Texas. Note that Strauss is an experimental physicist, not a theoretical physicist like Carroll.

Here’s another review of the debate by Randy Everist of Possible Worlds blog. He explains the back-and-forth over Boltzmann brains and the BGV theorem in more detail.