Don Page is one of the world’s leading experts on theoretical gravitational physics and cosmology, as well as a previous guest-blogger around these parts. (There are more world experts in theoretical physics than there are people who have guest-blogged for me, so the latter category is arguably a greater honor.) He is also, somewhat unusually among cosmologists, an Evangelical Christian, and interested in the relationship between cosmology and religious belief.
Longtime readers may have noticed that I’m not very religious myself. But I’m always willing to engage with people with whom I disagree, if the conversation is substantive and proceeds in good faith. I may disagree with Don, but I’m always interested in what he has to say.
Recently Don watched the debate I had with William Lane Craig on “God and Cosmology.” I think these remarks from a devoted Christian who understands the cosmology very well will be of interest to people on either side of the debate.
Open letter to Sean Carroll and William Lane Craig:
I just ran across your debate at the 2014 Greer-Heard Forum, and greatly enjoyed listening to it. Since my own views are often a combination of one or the others of yours (though they also often differ from both of yours), I thought I would give some comments.
I tend to be skeptical of philosophical arguments for the existence of God, since I do not believe there are any that start with assumptions universally accepted. My own attempt at what I call the Optimal Argument for God (one, two, three, four), certainly makes assumptions that only a small fraction of people, and perhaps even only a small fraction of theists, believe in, such as my assumption that the world is the best possible. You know that well, Sean, from my provocative seminar at Caltech in November on “Cosmological Ontology and Epistemology” that included this argument at the end.
I mainly think philosophical arguments might be useful for motivating someone to think about theism in a new way and perhaps raise the prior probability someone might assign to theism. I do think that if one assigns theism not too low a prior probability, the historical evidence for the life, teachings, death, and resurrection of Jesus can lead to a posterior probability for theism (and for Jesus being the Son of God) being quite high. But if one thinks a priori that theism is extremely improbable, then the historical evidence for the Resurrection would be discounted and not lead to a high posterior probability for theism.
I tend to favor a Bayesian approach in which one assigns prior probabilities based on simplicity and then weights these by the likelihoods (the probabilities that different theories assign to our observations) to get, when the product is normalized by dividing by the sum of the products for all theories, the posterior probabilities for the theories. Of course, this is an idealized approach, since we don’t yet have _any_ plausible complete theory for the universe to calculate the conditional probability, given the theory, of any realistic observation.
For me, when I consider evidence from cosmology and physics, I find it remarkable that it seems consistent with all we know that the ultimate theory might be extremely simple and yet lead to sentient experiences such as ours. A Bayesian analysis with Occam’s razor to assign simpler theories higher prior probabilities would favor simpler theories, but the observations we do make preclude the simplest possible theories (such as the theory that nothing concrete exists, or the theory that all logically possible sentient experiences occur with equal probability, which would presumably make ours have zero probability in this theory if there are indeed an infinite number of logically possible sentient experiences). So it seems mysterious why the best theory of the universe (which we don’t have yet) may be extremely simple but yet not maximally simple. I don’t see that naturalism would explain this, though it could well accept it as a brute fact.
One might think that adding the hypothesis that the world (all that exists) includes God would make the theory for the entire world more complex, but it is not obvious that is the case, since it might be that God is even simpler than the universe, so that one would get a simpler explanation starting with God than starting with just the universe. But I agree with your point, Sean, that theism is not very well defined, since for a complete theory of a world that includes God, one would need to specify the nature of God.
For example, I have postulated that God loves mathematical elegance, as well as loving to create sentient beings, so something like this might explain both why the laws of physics, and the quantum state of the universe, and the rules for getting from those to the probabilities of observations, seem much simpler than they might have been, and why there are sentient experiences with a rather high degree of order. However, I admit there is a lot of logically possible variation on what God’s nature could be, so that it seems to me that at least we humans have to take that nature as a brute fact, analogous to the way naturalists would have to take the laws of physics and other aspects of the natural universe as brute facts. I don’t think either theism or naturalism solves this problem, so it seems to me rather a matter of faith which makes more progress toward solving it. That is, theism per se cannot deduce from purely a priori reasoning the full nature of God (e.g., when would He prefer to maintain elegant laws of physics, and when would He prefer to cure someone from cancer in a truly miraculous way that changes the laws of physics), and naturalism per se cannot deduce from purely a priori reasoning the full nature of the universe (e.g., what are the dynamical laws of physics, what are the boundary conditions, what are the rules for getting probabilities, etc.).
In view of these beliefs of mine, I am not convinced that most philosophical arguments for the existence of God are very persuasive. In particular, I am highly skeptical of the Kalam Cosmological Argument, which I shall quote here from one of your slides, Bill:
- If the universe began to exist, then there is a transcendent cause
which brought the universe into existence. - The universe began to exist.
- Therefore, there is a transcendent cause which brought the
universe into existence.
I do not believe that the first premise is metaphysically necessary, and I am also not at all sure that our universe had a beginning. (I do believe that the first premise is true in the actual world, since I do believe that God exists as a transcendent cause which brought the universe into existence, but I do not see that this premise is true in all logically possible worlds.)
I agree with you, Sean, that we learn our ideas of causation from the lawfulness of nature and from the directionality of the second law of thermodynamics that lead to the commonsense view that causes precede their effects (or occur at the same time, if Bill insists). But then we have learned that the laws of physics are CPT invariant (essentially the same in each direction of time), so in a fundamental sense the future determines the past just as much as the past determines the future. I agree that just from our experience of the one-way causation we observe within the universe, which is just a merely effective description and not fundamental, we cannot logically derive the conclusion that the entire universe has a cause, since the effective unidirectional causation we commonly experience is something just within the universe and need not be extrapolated to a putative cause for the universe as a whole.
However, since to me the totality of data, including the historical evidence for the Resurrection of Jesus, is most simply explained by postulating that there is a God who is the Creator of the universe, I do believe by faith that God is indeed the cause of the universe (and indeed the ultimate Cause and Determiner of everything concrete, that is, everything not logically necessary, other than Himself—and I do believe, like Richard Swinburne, that God is concrete and not logically necessary, the ultimate brute fact). I have a hunch that God created a universe with apparent unidirectional causation in order to give His creatures some dim picture of the true causation that He has in relation to the universe He has created. But I do not see any metaphysical necessity in this.
(I have a similar hunch that God created us with the illusion of libertarian free will as a picture of the true freedom that He has, though it might be that if God does only what is best and if there is a unique best, one could object that even God does not have libertarian free will, but in any case I would believe that it would be better for God to do what is best than to have any putative libertarian free will, for which I see little value. Yet another hunch I have is that it is actually sentient experiences rather than created individual `persons’ that are fundamental, but God created our experiences to include beliefs that we are individual persons to give us a dim image of Him as the one true Person, or Persons in the Trinitarian perspective. However, this would take us too far afield from my points here.)
On the issue of whether our universe had a beginning, besides not believing that this is at all relevant to the issue of whether or not God exists, I agreed almost entirely with Sean’s points rather than yours, Bill, on this issue. We simply do not know whether or not our universe had a beginning, but there are certainly models, such as Sean’s with Jennifer Chen (hep-th/0410270 and gr-qc/0505037), that do not have a beginning. I myself have also favored a bounce model in which there is something like a quantum superposition of semiclassical spacetimes (though I don’t really think quantum theory gives probabilities for histories, just for sentient experiences), in most of which the universe contracts from past infinite time and then has a bounce to expand forever. In as much as these spacetimes are approximately classical throughout, there is a time in each that goes from minus infinity to plus infinity.
In this model, as in Sean’s, the coarse-grained entropy has a minimum at or near the time when the spatial volume is minimized (at the bounce), so that entropy increases in both directions away from the bounce. At times well away from the bounce, there is a strong arrow of time, so that in those regions if one defines the direction of time as the direction in which entropy increases, it is rather as if there are two expanding universes both coming out from the bounce. But it is erroneous to say that the bounce is a true beginning of time, since the structure of spacetime there (at least if there is an approximately classical spacetime there) has timelike curves going from a proper time of minus infinity through the bounce (say at proper time zero) and then to proper time of plus infinity. That is, there are worldlines that go through the bounce and have no beginning there, so it seems rather artificial to say the universe began at the bounce that is in the middle just because it happens to be when the entropy is minimized. I think Sean made this point very well in the debate.
In other words, in this model there is a time coordinate t on the spacetime (say the proper time t of a suitable collection of worldlines, such as timelike geodesics that are orthogonal to the extremal hypersurface of minimal spatial volume at the bounce, where one sets 
) that goes from minus infinity to plus infinity with no beginning (and no end). Well away from the bounce, there is a different thermodynamic time 
(increasing with increasing entropy) that for 
increases with 
but for 
decreases with (so there becomes more positive as becomes more negative). For example, if one said that is only defined for 
, say, one might have something like
the positive square root of one less than the square of . This thermodynamic time only has real values when the absolute value of the coordinate time , that is, 
, is no smaller than 1, and then increases with .
One might say that begins (at 
) at 
(for one universe that has growing as decreases from -1 to minus infinity) and at 
(for another universe that has growing as increases from +1 to plus infinity). But since the spacetime exists for all real , with respect to that time arising from general relativity there is no beginning and no end of this universe.
Bill, I think you also objected to a model like this by saying that it violates the second law (presumably in the sense that the coarse-grained entropy does not increase monotonically with for all real ). But if we exist for 
(or for 
; there would be no change to the overall behavior if were replaced with 
, since the laws are CPT invariant), then we would be in a region where the second law is observed to hold, with coarse-grained entropy increasing with 
(or with 
if ). A viable bounce model would have it so that it would be very difficult or impossible for us directly to observe the bounce region where the second law does not apply, so our observations would be in accord with the second law even though it does not apply for the entire universe. I think I objected to both of your probability estimates for various things regarding fine tuning. Probabilities depend on the theory or model, so without a definite model, one cannot claim that the probability for some feature like fine tuning is small. It was correct to list me among the people believing in fine tuning in the sense that I do believe that there are parameters that naively are far different from what one might expect (such as the cosmological constant), but I agreed with the sentiment of the woman questioner that there are not really probabilities in the absence of a model. Bill, you referred to using some “non-standard” probabilities, as if there is just one standard. But there isn’t. As Sean noted, there are models giving high probabilities for Boltzmann brain observations (which I think count strongly against such models) and other models giving low probabilities for them (which on this regard fits our ordered observations statistically). We don’t yet know the best model for avoiding Boltzmann brain domination (and, Sean, you know that I am skeptical of your recent ingenious model), though just because I am skeptical of this particular model does not imply that I believe that the problem is insoluble or gives evidence against a multiverse; in any case it seems also to be a problem that needs to be dealt with even in just single-universe models.
Sean, at one point your referred to some naive estimate of the very low probability of the flatness of the universe, but then you said that we now know the probability of flatness is very near unity. This is indeed true, as Stephen Hawking and I showed long ago (“How Probable Is Inflation?” Nuclear Physics B298, 789-809, 1988) when we used the canonical measure for classical universes, but one could get other probabilities by using other measures from other models.
In summary, I think the evidence from fine tuning is ambiguous, since the probabilities depend on the models. Whether or not the universe had a beginning also is ambiguous, and furthermore I don’t see that it has any relevance to the question of whether or not God exists, since the first premise of the Kalam cosmological argument is highly dubious metaphysically, depending on contingent intuitions we have developed from living in a universe with relatively simple laws of physics and with a strong thermodynamic arrow of time.
Nevertheless, in view of all the evidence, including both the elegance of the laws of physics, the existence of orderly sentient experiences, and the historical evidence, I do believe that God exists and think the world is actually simpler if it contains God than it would have been without God. So I do not agree with you, Sean, that naturalism is simpler than theism, though I can appreciate how you might view it that way.
Best wishes,
Don
Some theists believe in god because he does miracles (faith-healing, causing them to win football games, etc.), or used to (e.g., the resurrection). I did not know there were also some, like Dr. Page, who believe in god because he does not do miracles but rather runs his universe in a consistent, orderly fashion (although this would seem to leave the resurrection unexplained) under a simple set of rules which however includes General Relativity tensors and the Standard Model Lagrangian, at least as limiting cases.
Without a stable set of forces, chemical reactions, and so on, our type of life could not have developed via evolution. There might be other universes with more unstable conditions, but we won’t be found there if so (although some better class of beings might well). Once again, the evolutionary model explains the universe as I know it so far, and unlike the god hypothesis, does not cater to those on both sides of the fence.
Don, thanks for your active reading of the comments section. While you’re here, could you define “simple” for us? Preferably as used in the original post Sean provided and in your paper, “Religious and Scientific Faith in Simplicity.”
I admire others who wish to attack your points without even knowing your semantics, but I personally cannot agree or disagree with your claims until I know them.
Dear Don,
You looked over my previous questions, but in view of the supplemental information—about you as well as about your alleged positions—being “shared” (as premises of their questions) by the other (mostly) non-linked readers, here is one more (and possibly my last) question to you:
How does your idea of God differ from Aristotle’s?
Explanation is in order.
Aristotle was an ancient Greek; his work preceded Christianity. Aristotle’s God in the main was something like this (and please do correct me if I go wrong somewhere):
He Created the Orderly universe, Set everything in an Orderly motion, and just then, “leapt out the window” to “sit in meditation,” so to speak. He thus Created but also Refused to Participate. He Contemplates (whatever that means), but Focusing only on Himself—neither the world He Created nor the rest of us. He is the Prime Mover (because He Created it) and also the Unmoved Mover (because, Contemplating only Himself, He wouldn’t be aware of you and hence wouldn’t be moved either by your prayers or your pleas).
BTW, via his metaphysics—the most fundamental (and therefore the most consequential) branch of philosophy—Aristotle also denied any other world, including Plato’s world of ideas. A metaphysics of a purely imaginary world, one that is completely removed from (and perhaps also transcending) this world (which is both material and mental) has always served as the first anchor in every theory for every shade of mysticism, the religious mysticism included.
But, Don, let’s not worry too much about philosophy—esp. about delineation and refutation of the bad philosophies. Let’s think of God. Aristotle’s God.
Saint Thomas Aquinas “cut Aristotle loose” in the medieval Church. Realizing that God is Busy Contemplating only Himself, and not this world, some of the Christian monks—first, Aquinas’ students (the scholastic scholars)—and then still some others, began looking at this world, instead of to the God, to find answers to their problems. We were God’s products, but He was not whimsical; He would not help but the universe that He Created was Orderly, making reason efficacious, their Master had told them. The Rennaissance followed, as a product—and also, a slightly changed Christianity. Reason had virtuously gone beyond the Tipping Point. The Enlightenment, and then the Industrial Revolution followed—with further, and by now dramatic looking, changes to Christianity.
A lot else also followed, but let’s not go there: Plato, Kant, and their effects. Let’s try to keep ourselves on our track: what we mean by God.
In the wake of the far more recent (mostly contemporary) attempts at the revival of Christianity and the Christian God (both which got a great impetus during and after the Reagan era), how does a scientist of your standing, view Aristotle’s God? How does your God differ from Aristotle’s? For instance, as in contrast to, say, The Bible’s?
[Please allow me a personal note: It may come as a surprise to you, but frankly, when I posed my questions in my previous comment, I didn’t know much about your background or work. The link to your Alberta Web page that Sean supplied is broken, and so, I had then very briefly checked the Wiki article on you—and only that, nothing else. Once I knew you were a cosmologist with a PhD from CalTech and a later MA from Cambridge under Hawkins, I closed the Wiki article—you were not a theologian, I had confirmed. … It’s only now (after reading the other reader’s replies) that I revisited the Wiki and browsed more on you, notably, your Jewell interview (a link at the Wiki), etc. … Of course, though I stick by my previous comment questions, I thought of further asking the current question—it would be more pertinent, given your background.]
Best,
–Ajit
[E&OE]
“Are you alive, or not? Is there nothing in your head?”
But
O O O O that Tiplerian Rag—
It’s so elegant
So intelligent
Ray
You mention 1 Corinthians 9. You actually highlight why I believe Christian scripture, and it is a little Bayesian in the subjective sense. The apostles had a right to support, in the view of Paul, because they laboured hard to spread the gospel and oversee the church, not so they had a comfortable and privileged life. Some modern Christian TV personalities don’t help much here. But Paul forfeited this right where he felt the church needed to see that his motivation was not their financial support (1 Thessalonians 2v9, 2 Thessalonians 3v8). Elsewhere Paul says that a man who will not work should not eat (2 Thessalonians 3v10). In 2 Corinthians 11 he discusses what he has gone through personally for the gospel.
If you are going to try to drill scripture full of holes, (the parts which clearly purport to be historical discourse and not perhaps poetic/allegorical) and those holes don’t bear much scrutiny, then perhaps it’s just all basically true. There was a BBC series called Credo a few years ago where some learned woman attempted to dismantle the NT scriptures with her intellect. It only worked if you don’t know them well. Basically it was garbage. There is too much insight and coherence.
Don
Thanks for your post and comments. I am a mediocre BSc applied physicist who became a Christian at university. I am perhaps a ‘cosmology defeatist’ in terms of ultimate origins. Could be because I’m not that bright or could be because I see probable inherent limitations in the human processes of investigation. I am however interested in seeing the beliefs you hold about the veracity of the Bible in general; the sort of questions asked by Peter above. Partly to know your thoughts, partly because if you don’t wish to then I might have a go!
Bob
You are hypothesizing from your pre-existing faith in evolution. It is your priority reality datum. As I said, one problem with that is your brain, allegedly a product of evolution by natural selection, is a piece of computational apparatus optimized to help you survive. Any function for absolute truth evaluation it has would be secondary, would it not? (An F 16 is a machine, but it is not optimized to solve cosmology conundrums). Are you therefore not really interested in absolute truth when it comes to origins? You did not answer this point. Yes, religion makes claims about absolute truth. Are you saying that science is not really after reality? What are your semantics here?
Daniel Kerr has it: the simplicity Prof Page refers to appears to be linguistic, but this is not the sense in which we prefer theories that are simple. Yudkowsky writes on Occam and Bayes, reminding us that what we’re talking about wrt complexity and Occam is “how long is a program that models this?”, not “how short is the sentence in English which describes this?”. Otherwise, it seems that the “simplest” explanation is something like Heinlein’s “the lady down the street is a witch, she did it”.
I am aware of a Christian tradition that says that God is simple in the sense of having no internal parts. Again, this is not the computational sense in which we say that a theory is simple. The Christian God is extremely complex in that computation sense, being all knowing and behaving in ways which are very hard to model.
Some theological elaboration for other commenters, from this former evangelical Christian physicist (only as an undergrad, now I write software): “evangelical” refers to a subset of Protestant Christianity which typically emphases the need for personal repentance and faith, as well as the inerrancy of the Bible. Quite what inerrancy means is debated, since evangelicals allow that the Bible contains different types of literature, not all of which are intended as reportage. Not everyone who describes themselves as an evangelical would be a young Earth creationist, for example. So, the opinion of the Pope is not that relevant to a discussion of Prof Page’s beliefs.
Ajit, I have learned that many Christians of the first 3-4 centuries were universalists, but after Augustine, the majority in the Western Church rejected this view. My universalism is probably still a minority view, but I have recently become convinced that it is the better fit to the entire Biblical evidence of a God of love and forgiveness. For example, one specific idea that I learned which was new to me was that the Greek phrase that is often translated “everlasting punishment” might be better translated “correction in the age to come” or “discipline from the One who is eternal.”
Peter, answering your 7 questions would, I think, take up more space than most others would want me to use here, but if you are interested, look up my email address in one of my cited papers and send me an email.
Andrew, I have been fortunate to be in a physics community that has generally been quite tolerant of my minority views within this community. I haven’t personally noticed increased hostility, though I have heard younger Christians express fear for this careers if they made their faith more public. I have probably become more forthcoming about my faith with age because of increasing confidence of its relation with science, though I readily recognize that my often minority views are highly tentative.
Daniel Kerr, by “simple” I mean not requiring much information to specify completely. For example, I regard the set of natural numbers (positive integers) as much simpler than nearly all of its individual members. An omniscient, omnipotent, omnibenevolent God I also regard as simpler than a god who has large but finite knowledge, power, and love. But I recognize that simplicity depends on background knowledge and does seem to be at least somewhat unavoidably subjective, which is a limitation to an unambiguous application of Occam’s razor in science and other fields of knowledge.
Ajit, on your later comment, I believe Aristotle had some good insights into the nature of God, but I believe that Jesus is the fullest revelation as God’s own Son. I believe that the Incarnation shows us that God loves us deeply and knows what we experience as His creatures. So I believe that God is not an impassive god but one who feels what we feel and partakes in our sufferings.
Simon Packer, if our universe were just random (or if we were Boltzmann brains), it would indeed seem surprising that our brains that evolved to survive would be able to arrive at truth in areas such as abstract mathematics that do not appear to have much survival value. But I believe that God designed the laws of physics so that Boltzmann brains do not dominate and so that evolution would lead to sentient beings like us who can know truth in areas far beyond that needed for survival. Of course, the differences in opinion about metaphysical areas shows that we are not designed to come to unique truths in all difficult areas.
“Gods are fragile things; they may be killed by a whiff of science or a dose of common sense.” – Chapman Cohen (1868 – 1954)
Simon Packer says
Bob
You are hypothesizing from your pre-existing faith in evolution. It is your priority reality datum. As I said, one problem with that is your brain, allegedly a product of evolution by natural selection, is a piece of computational apparatus optimized to help you survive. Any function for absolute truth evaluation it has would be secondary, would it not? (An F 16 is a machine, but it is not optimized to solve cosmology conundrums). Are you therefore not really interested in absolute truth when it comes to origins? You did not answer this point. Yes, religion makes claims about absolute truth. Are you saying that science is not really after reality? What are your semantics here?
))))))))))))
That you connect the word faith with evolution is quite telling. Religious people see the world through faith, that is choosing to believe what they want to believe in spite of any evidence refuting it. They sometime build elaborate rationalizations to create the appearance of a reasoned position build on evidence but it’s a sham. There is no evidence and no facts that can change their mind. Even worst, among the religious having “faith” is viewed as virtuous, even bestowing some kind of moral superiority on those holding faith.
This is not how science works obviously, faith is not operative in science, faith is exactly what scientists , when they think as scientists , never have. All we can do in science, is build models of reality , mathematical models in the case of physics, and test these models by their ability to make correct predictions as well as how logically consistent they are in the larger framework of successful theory.
In some sense, all we can do in science is prove things wrong. A given theory is accepted as long as an experiment or observation doesn’t prove it wrong. Our best theories , Quantum Mechanics and General relativity have survived many such tests, at least so far. Older theories, like Newtonian Gravity or Maxwell’s Electromagnetic theory , while found to fail in certain contexts , remain useful in many applications. This is because these were well tested theories of their time.
The theory of evolution is a very well tested theory. Biological knowledge is well beyond what Darwin knew, but this expanded understanding has only made Darwin’s hypotheses more secure, at least in general outline. I don’t have faith , let alone a pre existing faith whatever that means in evolution. For me , faith is simply not operative in my world view.
Don
Thanks for your kind and considered responses. I think we are both agreed that it is God’s intent in Christ to include all mankind in his family. You are inclined to believe he will succeed, I am not at all sure about that, though I want it because God wants it.
From your comments on abstract thought and survival I assume you believe in some sort of guided/intelligently seeded/constrained evolutionary scenario? Or is it all just an inevitable outcome of some minimal, to be discovered, basic physics? Emergent outcomes of a supremely elegant core mathematical model?
Bob
I am aware of the usual usages of the words ‘faith’ and ‘science’. In the case of QM, GR and Christianity I have no problem with the commonly accepted classifications. In the case of evolution by natural selection, I would put the theory in a different category to you.
Bob
I am aware of the usual usages of the words ‘faith’ and ‘science’. In the case of QM, GR and Christianity I have no problem with the commonly accepted classifications. In the case of evolution by natural selection, I would put the theory in a different category to you.
))))))))))))))
Why?
Simon Packer: So, did all life get specially created, or do you think things proceeded more or less as current science says they did, except that humans were created in 4004 BC or so? When was the Fall, in your model?
I was interested when you said that “God has allowed the creation, as well as the creatures, to reflect the cosmic fallen spiritual environment.” Natural evils (earthquakes and suchlike) are a reflection of laws of nature which do not care whether humans get hurt. If you think there was a Fall at a particular point in time after humans were created, are you saying the laws changed at some point? Did they change only on Earth, or throughout the Universe? If only on Earth, where was the interface between the two sets of laws, prior to the Fall? That would have been a truly interesting place for physics research 😉
Thank you for answer, Don. I guess I still don’t know if I could agree with your claims about faith in simplicity since the set of natural numbers requires a lot of complex information to specify in say mereology (with the appropriate choice of axioms) or the game of life. Both are Turing complete languages capable of expressing predicate logic, set theory, and thus all mathematical theories. Unless God has a preferred language to express such ideas and we can make an argument for why God prefers that language, I don’t know how to proceed.
One could argue naturalism, the empirical, physical world, is that language, but then specifying the set of natural numbers requires an impossible amount of information, as you have to encode every possible representation of the natural numbers in the physical world, a set which I feel is practically uncomputable if not completely uncomputable. This is analogous to Jerry Fodor’s “special sciences” where I’m claiming that if physics is God’s preferred language, then the language require to express mathematics is a special science emergent from physics.
More to the point, unless God has a direct physical expression (physical existence), we run into the same problems of expression as we do for the natural numbers. If physics is God’s preferred language, there’s no way He is the simplest model expressible in that language if he doesn’t physically have a form in that language.
Don replied to Andrew this way:
—-
Since I believe in a God of order, whom I believe would create a very elegant universe, the experimental discoveries supporting a moderately simple Standard Model of Particle Physics (even though we hope for an even simpler ultimate theory) have increases my posterior belief in God, as has the cosmological data supporting the Standard Model of Cosmology (though here I also hope for an even simpler multiverse model).
On the other hand, all sorts of logically possible but crazy things would decrease my posterior belief, such as CERN not being able to reproduce any evidence for the Higgs boson next year, seeing electrons decay into uncharged particles with a lifetime much less than the current lower limits, not being able to see distant stars any more, and on and on with all sorts of things that could be different if God did not continue to run the universe in the orderly way He does now.
—-
What Don says here would make him more sure of the existence of a god would make me less sure, since physics predicts what it does and that’s what we observe.
Suppose we have, as Don imagines, a collection of possible pieces of observational evidence
E={E1, E2, …}
that we might make, some of which are consistent with the hypothesis
Q=”physics is all there is”
and some of which are inconsistent with Q but consistent with the alternative hypothesis
R=”physics is not all there is”
The possible pieces of evidence that Don imagines include some that are consistent with Q and some that are inconsistent with Q. If Q is true, we can be certain that any piece of evidence Ek that we happen to observe will be consistent with Q:
P(Having observed Ek, we determine that Ek is consistent with Q | Q) = 1
whereas we can be sure that that piece of evidence is not inconsistent with Q:
P(Having observed Ek, we determine that Ek is inconsistent with Q | Q) = 0
Having observed any random Ek, this is the likelihood that we will determine that it is consistent with Q, given that “physics is all there is”.
But suppose R is true. Suppose we happen to observe a particular En. What is the probability that we will determine that it is inconsistent with Q? Could it still be observed, given that R is true? The answer is “yes,” if we hypothesize that R entails the existence of a god that is omnipotent and therefore capable of making anything happen that it wishes (such as resurrections and other miracles, for example, that are contrary to physical law).
Therefore we have the following likelihood under the alternative hypothesis:
P(Having observed Ek, we determine that Ek is inconsistent with Q | R) > 0
and
P(Having observed Ek, we determine that Ek is consistent with Q | R) 1
That is, every time that we observe a piece of evidence Ek that is consistent with the hypothesis that “physics is all there is,” we find that it supports “physics is all there is” and undermines the alternative hypothesis that includes an omnipotent god (or for that matter, even a semi-powerful god that is capable of subverting physical law on some occasions).
Alternatively, every time we observe a piece of evidence Ek, we can compute the likelihood ratio that we will observe it to be inconsistent with Q:
P(Having observed Ek we determine that Ek is inconsistent with Q | Q) /
P(Having observed Ek we determine that Ek is inconsistent with Q | R) = 0
In other words, observing just a single piece of evidence, a single miracle, the Resurrection, for example, does not merely undermine the hypothesis that physics is all there is, it refutes it.
From a Bayesian point of view, regardless of your choice of prior probabilities of P(Q) and P(R), Bayes’ theorem tells us that as we continue to observe more and more data, each piece of which is consistent with Q, then the posterior odds ratio simply gets larger and larger, and regardless of your choice of prior, the posterior probability of “physics is all there is” approaches 1.
So I am mystified by Don’s comment that observing more and more data that is only consistent with what physics says we should observe makes him more confident of the existence of a god, whereas observing data inconsistent with physics would make him doubt the existence of god. It seems to me he’s got it entirely backward.
Now it may be that the god that Don believes in only produces results that are consistent with Q, and that he eschews miracles, the god of deism, if you will, who does not meddle with the universe. If this is what he believes, then the likelihoods corresponding to his god are identical to those under Q, that is, 1 if Ek is consistent with Q and 0 otherwise; in that case, all the likelihood ratios are 1, the posterior probabilities after observing a ton of data that are all consistent with Q is identical to the prior probabilities, and one learns nothing about the existence of that god regardless of how much data is observed. So even there, Don’s comment mystifies me.
See here:
http://bayesrules.net/anthropic.html
…which was published in “The Improbability of God,” edited by Michael Martin and Rickie Monnier (starts on p. 150)
One line contains a typo. Should read:
P(Having observed Ek, we determine that Ek is consistent with Q | R) < 1
In partial summation (because I couldn’t do justice to all the fine comments above, mine excluded), we skeptics have what we feel are are sound reasons for considering the Jesus story to be mainly myth, and the need for a god to explain anything we see around us (including things we don’t understand and may never understand as a species) to be vanishingly small. I would hope our comments have at least established that we have given this matter considerable thought and are equally entitled to our conclusions as any theist. Particularly since, in my case, such conclusions were reached despite 19 years of attending Sunday School, Sunday morning Church service, Sunday evening Youth Service, Daily Vacation Bible School, and Thursday afternoon Release Time Religious Education at my public school. (The Protestants were marched out of school to nearest Protestant church and the Catholics to the nearest Catholic church. I wonder if this is still done these days, since it doesn’t seem very constitutional, albeit it was ‘voluntary’.) (This regimen was a de facto civic requirement in the U.S.A in the 1950’s and 1960’s, when I grew up.)
Thank you all for a wonderful discussion, especially to Don. Don, your gracious manners and honest assessment is appreciated.
All in all it is time, as Simon and others expressed in this blog, to acknowledge that in spite of science’s achievements, reality is more than what naturalist are prepared to accept.
Don it’s nice to see you participating in these comments. It’s also rare to get a theist’s viewpoint as yours, so that’s nice also.
I would like to ask how is it that god can be simple though? Certainly god has preferences of some sort that direct his action. Certainly god decided on a specific universe to create.
Perhaps you’d address these as saying god’s choices stem from the “best” result? But aren’t “good” and “best” contextual, if not entirely subjective, ideas? Or maybe you might mention that the universe is as it is because god didn’t have much of a choice in the matter. But wouldn’t we have little evidence for that?
Just wondering if you could respond to those thoughts.
Thanks, Dr. Carroll, for the opportunity to read Dr. Page’s thoughts. His post as a response to your debate with WL Craig sparked my interest. I refer your debate to others as the most civil debate I’ve reviewed.
I respect Dr. Page’s professional background and his congenial personality seems affirmed by you and several others. As a layperson in physics I can’t keep up with the details but can follow the gist of the arguments. What baffles me is he seems to easily put aside philosophical, fine tuning, and first causer arguments for deity, yet remains faithful that one exists AND the world is a better place for it.
I would find it stimulating to hear Dr. Page speak (or write) more at length over how he remains faithful rather than hopefully agnostic. He seems to me, at this point of brief introduction, to be similar to Dr. Collins at the NIH. It could even be interesting for the two of them to discuss “faith versus evidence,” as this seems to be at the heart of much heartburn.
Dear Don,
Thanks for responding. I really appreciate it.
… Ummm… I don’t think I agree with you (or that I ever possibly could), but then, guess this is not a forum or a place to look too closely or finely into all such points. … And, for that matter, as far as I am concerned, given the firmness of your religious and ideas-wise convictions, I am not even sure whether a further debate on my part would ever really be called for. Guess the exercise would be pointless.
In any case, when it comes to matters like these—I mean the matters of personal religious/philosophical convictions or opinions—debates and all are mostly of a secondary/tertiary importance to me. I am an engineer (also with interests in physics), not a theologian or philosopher, and I acknowledge that people, after all, do differ in their opinions; they do have quite different outlooks on many such issues.
The important point is the no-initiation-of-force principle. So long as this principle is honoured by every one involved, guess it is pretty easy to accept any differences of opinions or even of convictions—at least I am fairly comfortable with that.
But, yes, one is curious to know in a general sense where the other person stands, how he views the world, how he deals with some of the salient objections, and things like that…. So, on that count, thanks for being so forthcoming…
All in all, it has been nice interacting with you. … Let me close my own participation on this thread on that note (though I am sure I would come back later on, just to check out the further developments, if any, on this thread).
Best,
–Ajit
[E&OE]
We all acknowledge that the world is not perfect, so that means God must be operating under constraints. Can you please tell us who sets these constraints that God must follow?
Omnipotence ain’t what it used to be.
people typically use the word ‘God’ to refer to whatever it is that is responsible for the world being the way it is. So technically it is a question rather than an answer. The notion that God either does or does not exist is fundamentally idiotic; it is not like asking whether a theory is true or not, and even that gets complicated. What is in scripture tries to accumulate whatever has been learned the hard way, with memorable stories.