Guest Post: Don Page on God and Cosmology

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:

  1. If the universe began to exist, then there is a transcendent cause
    which brought the universe into existence.
  2. The universe began to exist.
  3. 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 t = 0) 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 t' (increasing with increasing entropy) that for t >> 0 increases with t but for $latex t << 0$ decreases with $latex t$ (so there $latex t'$ becomes more positive as $latex t$ becomes more negative). For example, if one said that $latex t'$ is only defined for $latex |t| > 1$, say, one might have something like

t' = (t^2 - 1)^{1/2},

the positive square root of one less than the square of t. This thermodynamic time t' only has real values when the absolute value of the coordinate time t, that is, |t|, is no smaller than 1, and then t' increases with |t|.

One might say that t' begins (at t' = 0) at t = -1 (for one universe that has t' growing as t decreases from -1 to minus infinity) and at t = +1 (for another universe that has t' growing as t increases from +1 to plus infinity). But since the spacetime exists for all real t, 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 t for all real t). But if we exist for t >> 1 (or for $latex t << -1$; there would be no change to the overall behavior if $latex t$ were replaced with $latex -t$, 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 $latex t' \sim t$ (or with $latex t' \sim -t$ if $latex t << -1$). 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

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960 Responses to Guest Post: Don Page on God and Cosmology

  1. Ben Goren says:

    Don,

    I do believe you owe it to yourself to read Richard Carrier’s latest book, On the Historicity of Jesus. It is a peer-reviewed scholarly work that performs a Bayesian analysis of the evidence for Jesus and the events of the Gospel. And, despite it being of top academic quality, it’s also most readable and engaging.

    I dare say you’ll find much cause to reevaluate your priors.

    Cheers,

    b&

  2. Coel says:

    Two quick comments:

    First, I’m rather amazed that anyone other than a Biblical literalist would even claim that there is any “historical evidence for the resurrection”.

    Second, regarding:

    “I do believe that God exists and think the world is actually simpler if it contains God than it would have been without God.”

    If the claim is that God is simple, can you give us a blueprint for a being of the capabilities of such a god? One side of a piece of paper should suffice if this god is “simple”. But, surely all our evidence is that as beings get more intelligent and sentient and capable, they get vastly more complicated.

  3. “…despite it being of top academic quality….”

    I have tried to take the book (and Carrier in general) seriously and simply cannot.

    Sean — thanks for posting Don’s comments.

  4. Mario R Silveira says:

    Dear Iuda, these people are calling on me! Arguably, the best part of my religiously scientific inquiring is target on the God-Guy on the Cross…. The synthesis I am after requires undertanding Jesus on my body, on my heart, on my mind and then on my whole spirit.

    To give it the necessary scientific strength, like Spinoza´s Ethics, I take the words of Martin Buber as an axiom: The Sacred Bible is focused solely on the “Revelation of God in History”. This is true for both the Jewish and Christian Testaments. God give eternal glory to Buber since this axiom is as beautiful, ethical and glorious as the principle of equivalence of Einstein. And God forgive Martin Buber for not being able to target the true messianic role of Christ.

    Love

  5. Torbjörn Larsson says:

    There is no “debate” between science and religion about how the world works, since religion lost out long ago.

    So I am simply going to make the same two points that everyone else has and will:

    – Adding a factor makes a model more at risk for statistical over-fitting (“less parsimonious”, “razed by Occam”, …), independent of the causal ordering of the process. This is elementary statistics.

    And religious magic is superfluous, indeed rejected by age old theories like thermodynamics (no magic observed acting on closed systems), et cetera.

    – The mythical founder of a religion described in its own myth is simply not a historical person, to the degree of standards of historians (such as contemporary descriptions or depictions, connections with buildings, et cetera). JC (Julius Caesar) is a historical person, “JC” (the myth) is not.

    Indeed, it is an interesting observation that none of the mythical founders of religions, who are always self-described by the religion’s own myths, are verified as historical persons. That is, up until the invention of the printing press and more extensive public education, after which follows a long line of verified scam artists (such as Smith, Blavatsky, Steiner, Hubbard, Moon, Asahara, …) One can make of that what one wants.

    To close, when someone entertain the idea that a religious myth is describing something real, despite historians have clear tests re historicity, I use to recommend the Outsider Test for religion. It goes something like this:

    – We can observe that religions evolve like species, they are sourced at an origin and members learn it from their society. Therefore a religious person should be able to recognize that he or she needs to level the same kind of criticism against his own religion that he or she does against all the rest.

    – Those religions have obviously failed to get to standards, in the eyes of the religious person. What do we expect would be the result of fair criticism re his or hers idiosyncratic religion?

    Rejecting religious special pleading, such as historicity then it is not generally accepted, is a good start.

  6. Bob Zannelli says:

    Don Page is a first rate cosmologist, and a very nice guy to boot. He is scrupulously honest and while I reject his evangelical Christianity I have great respect for him. Thanks for posting this Sean.

  7. Daniel Kerr says:

    That was really engaging and it’s refreshing to see rational arguments for theism in a space usually flooded by atheistic rhetoric. I do not identify with theism but I feel it’s important for atheists to know the strong arguments for them.

    My only confusion in this work is the use of the term “simple.” Both when discussing theories describing the universe and the last claim that naturalism is simpler than theism. Much like the point that probabilities (read as a metric) depend on the model, so does simplicity depend on the choice of metric.

    I think it’s fair to say this argument uses a linguistic metric for simplicity. The theory that nothing exists is certainly the linguistically most simplistic theory, but if we used a mathematical basis for our metric for simplicity, “nothing” is the most complex object that can be expressed. In order to state it logically, rigorously you need to formulate that it is the negation of every other expressible theory. The situation is less clear when you use a physical basis for the simplicity metric. There is no correspondence between linguistic simplicity and physical simplicity. “Nothing” is especially complex physically. This is mired by the fact that a physical metric already assumes a model for physics. So I don’t really see how linguistic simplicity is the default concept of simplicity to use especially since in a complete theory of the universe, our languages and thus this concept of simplicity has to emerge from the theory. It isn’t fundamental.

  8. Tom Murphy says:

    I got off the religious bandwagon when I realized that a god worthy of the moniker, at least as Christians see it, would be perfect—i.e., lacking nothing of what is, including all perceivers. To my mind, that comprises nothing less than the universe. Anything more is superfluous; indeed impossible, as it would, by definition, be included in the universe.
     
    FWIW, the big question for me is that of the origin of the universe, which I tend to regard as an erstwhile naked singularity equivalent to no-thing.

  9. Jason says:

    Don,

    Ben and Coel got to the main points first in their comments so I would just add one more thing: Even if there is a god of some sort, how do you read the bible -e.g., Matthew 27:52 where it says holy people came out of their graves when Jesus died- and come away with any confidence you’re reading actual history?

    I don’t think I’m being hyperbolic when I say “the historical evidence for the life, teachings, death, and resurrection of Jesus”, as you put it, doesn’t register on modern historical radar. To compound the issue, the Gospels are clearly theological arguments. It’s not arbitrary why the author of Matthew chose zombies for his story (look no further than Daniel 12:2. Voila, zombies). It’s not only that we’re assigning a very low probability to these claims. It’s that there exists much more probable explanations for the claims.

    Regards.

  10. Kasuha says:

    First of all, God is personification of unreliability. Where God acts, things happen out of order. Believing in God taking care of things following laws of physics over and over again is the same as believing in science as the true explanation of the Universe and I think the notion of God in such case is possible but unnecessary. Unless we choose to see the God behind everything, the only places where we can find our God is where things happen in a way science cannot explain.

    God may not be a good scientific theory as it can’t be used to produce any testable predictions. But in my opinion, God still is a good default scientific theory. If there is no explanation of a phenomenon or all available non-god-involving explanations are too crazy to believe or choose from, there’s nothing wrong on choosing to believe God caused it.

    For humans, God is an answer, an explanation. This goes up to the point what a human conscience is. I’ll reiterate my idea that conscience is a running comparison of an Universe model running in our mind with reality. The difference between results of that model and what our senses provide us, the process of figuring out the order in these differences and improving the match and the strive to get rid of all these differences, that is conscience. God is the default answer here, the default way of dealing with a mismatch. Things are different from what we expect because someone superior to us decided that way and there’s no way to find out why or when it will happen again. We might find better answers eventually, but if we choose not to, by believing in God we move such differences to the area where we don’t care about them.

  11. barry goldman says:

    Another piece of writing with god and science in the title which describes the science in some detail, but never describes why the author was led to be interested in this god creature let alone what observations he made to lead him to want to discuss the god creature.

    arghh… so dishonest.

    I just found this book in the library yesterday: “God’s Planet” by Owen Gingerich. He spends PAGES describing copernican cosmology, darwin on evolution, Hoyle on cosmology but NEVER comes out and even mentions why he personally would be motivated to add a god to this picture. let alone a broad history of observation and thought about what this god is. at one point he throws in some confusing stuff about “adam and eve” and mitochondrial eve. nothing even on the archeology/philology etc… of the hebrew bible from which ‘adam and eve comes from.

    I first was alerted to this annoying practice when i skimmed through Ken Miller’s “finding Darwin’s God”. again pages and pages of detailed analysis of biology, and physics (presumably Miller practiced some biology (though he said he got interested in it to attact a babe)) but NO mention of his EXPERIENCE of this god and jesus and mary he very oddly brings into the discussion.

    If a scientist wants to talk about god, let’s see him do some experiments on this god and report them in the journals. that’s all i ask.

  12. My impression is that Don is not an Evangelical Christian in the sense in which that is normally understood (e.g. “God said it, I believe it, that settles it”). Perhaps it would help if he defines this term.

    Question for Don: I suspect that you did not become a Christian because of arguments like the ones presented here, but for other reasons. Is that true?

  13. It is called “faith” and not “knowledge”, so debate about religion with true believers is usually rather fruitless. If someone has some information which, by definition, is not scientific, and which I don’t have, then I can’t refute his arguments in debate. As Pirsig said, such a person might be right, but is probably better off in a monastery than in a university.

    I do have a question for Don, though: What is the reason you believe in your God and not in, say, Zeus or Odin? Most of the arguments are applicable to all three (and, indeed, to many other gods).

    Almost everyone is a completely confident atheist, with respect to all gods, except perhaps his own. In other words, I think the easiest way for a religious person to understand how atheists think is to ask himself how he thinks about, say, Quetzelcoatl or Baal.

  14. Bob Zannelli says:

    The idea of a universe evolving in both directions of time, which the late Vic Stenger called a Biverse in his writings, is a feature of a lot of origin models. Linde’s quantum tunneling model, the Hawking Hartle No Boundary model ( pointed out by Don Page) , the Carroll Chen model, The Aguirre Gratton steady state model , the Gasperini Veneziano pre big bang model , the Loop Quantum Gravity folks with their bounce prediction and so on.

    We of course don’t know how the Universe came into existence ( or if it eternal in some way to the past) but it is at least plausible that when space and time are brought into the quantum realm ( Third Quantization) we get quantum fluctuations that produce universes. This is analogous to zero point quantum fluctuations in standard Quantum Field Theory.

    In the case of QFT we model these quantum field fluctuations as the creation and annihilation of virtual particles. The thing to note is that we always get time reversed particle pairs. ( In a vacuum Bubble loop
    diagram we also include a boson connecting the creation and annihilation vertexes.) Therefore, we might think of two entangled universes fluctuating into existence in the “void” of third quantization. Most of these fluctuations don’t produce universes, but there is a non zero probability that they can be in the right energy condition to begin to inflate. Then these “universe pairs” cross the line from virtual to real.

    Also as Page has argued , the Decoherence functional is time symmetric , in that we can expect it to produce Decoherent histories in both directions of time, i.e. time reversed histories. So I would argue that the “Biverse” is at least a plausible idea, assuming that these third quantization proposals are plausible.

  15. Ron Murphy says:

    “such as my assumption that the world is the best possible”

    Why would anyone make such an assumption? Based on what? Compared to what? What’s a worse world? What are the metrics?

    “I mainly think philosophical arguments might be useful for motivating someone”

    Like propaganda?

    “ … raise the prior probability someone might assign to theism. I do think that if one assigns theism not too low a prior probability …”

    You shouldn’t have a prior probability about something for which you have zero data. The prior probability isn’t 100%, isn’t 0%, isn’t 50% – it’s unknown. No data. Making a guess, or expressing a bias from personal religiosity and assigning a probability is doing a great injustice to probability.

    “the historical evidence for the life, teachings, death, and resurrection of Jesus”

    What, like hearsay of Josephus passed off as evidence? http://ronmurp.net/2015/02/08/josephus-on-christianity-is-hearsay/. There is no historical record of the words or teachings of Jesus. The death? We can barely support his existence, by extensive hearsay, but as ‘evidence’ it’s no better than claims made about Mohammed’s revelations. By the way, how do you set the prior probability that Mohammed was telling the truth about his revelations, or the likelihood he was lying, or delusional? What’s the prior probability that Jesus was a nutty preacher. Using the statistics of what we do know about how common nutty preachers were at the time the best evidence we have is he’s one of many. I’d really like to know on what basis all this is judged remotely true.

    “can lead to a posterior probability for theism (and for Jesus being the Son of God) being quite high.”

    Yes, but if I start with a priory probability of 100% that God does not exist then I can go straight to a posterior probability God does not exist that’s, well, 100%.

    This really will not do. For miraculous things to happen, such as a resurrection, you need a God. You presuppose a God. Then you find stuff that’s in a book that says, look, here’s a miracle of that God – without any evidence it happened beyond hearsay, and again I remind you your hearsay is competing with that about Mohammed. Then you say, look, it’s all real, Christianity rules, OK.

    “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.”

    You are mistaken in that direction too. There is no need to think theism is improbable. One has only to be totally open to it, and then look at the evidence. There is none. What is offered as evidence turns out to be unevidenced hearsay, nothing that can’t be illusions and delusions, lies and propaganda with at least some actual prior probabilities because we know that these latter human frailties do actually occur.

    “I tend to favor a Bayesian approach in which one assigns prior probabilities”

    But Bayesian stuff works only when you have actual statistics to form your prior probabilities. It’s no better than a pretence at mathematical credibility when there’s no data to work with.

    “when the product is normalized by dividing by the sum of the products for all theories”

    This is crazy talk. Are probabilites based on the human capacity to imagine ideas? This is not to be treated like some meta-analysis of numerous sets of actual statistical results. It’s a met-analysis of guesses. It’s pointless.

    “… 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.”

    So, the correct response to the question of whether there is some sort of intelligent agent creator of universes is to say: I haven’t got the foggiest clue. From there proceed to act on what we do have. The empirical investigation of the universe and what that tells us. Our understanding of minute physics may still be open to question, but at the level of chemistry, creating medicines, building planes that don’t fall out the sky randomly – and it’s all quite mechanistic, naturalistic.

    The working conclusion, then, is to live **as if** this that we empirically find is all there is, whether it is or not, because if we cannot detect a god of any kind knowingly then whether there is one or not makes no different.

    “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 …”

    The pretend evidence for the resurrection is most simply explained by being the myth of one of the many myth asserting religions.

    This is no more than affirming the consequent, invoking a circular argument. You could only make an argument if you have good evidence of a God, and then good evidence of a naturalism busting resurrection. You have evidence of neither. You are presupposing there’s a God that can do stuff like resurrections, taking one of the many myths and taking that to be caused by this presupposed God, and then using that resurrection of the evidence of the divine Jesus, who is God.

    “I do believe by faith…”

    In which case you can dismiss all you said before this point as it means nothing in that context. And I can dismiss anything that now follows.

    “We simply do not know whether or not our universe had a beginning, but there are certainly models”

    See, you can do it correctly if you try. We simply do not know. And, for God there are no models that are based on other confirmed models of physics and cosmology. Sean’s work does not come out of nowhere, but all religions do: there’s always someone that we know invented a religion, or the origins of the religion are lost entirely in time. You really should be applying this to God: we do not know and we have no models. There are no measurements, no mathematic models, nothing but hearsay and the occasional claims of messianic individuals that think they are hooked up with their own go.

    “In summary, I think the evidence from fine tuning is ambiguous”

    Ambiguous? It’s down right dumb. What do we know about extra-universe ‘physics’ of universe creation such that it does not necessarily cause universes just like this one. How do we know that all universes are such that only initial conditions determine whether life evolves abundantly, rarely or not at all in such universes. We don’t know that the constants that **allow** evolved like actually **necessitate** evolved life. With different initial conditions it could be that the universe evolve without ever experiencing intelligent life that wonders if the universe is fine tuned. We’d then have a ‘fine tuned’ universe tuned with no tuned products in it. What reason would we have to think such a universe is fine tuned?

    There’s a big difference between speculative interpretations of limited cosmological data with multiple speculatively viable theories, on the one hand, and believing ancient religious stories based on stuff that’s indistinguishable from all the other stories you too would pass off as myth. That difference is that with physics one does not tend to make assertions about behaviour an morality based on them – unless they very specifically inform our understanding of human behaviour and morality, such as evolution, psychology, neuroscience. There are no moral or behavioural prescriptions or proscriptions associated with Sean’s preference for Everett, but there are real human consequences that result from people believing stuff for which there is no evidence in religion, and the consequences are all too often not good.

  16. Mark Jones says:

    Good to hear from a really well scientifically informed theist.

    I haven’t had a chance to look at Don’s links, but looking at this piece he is persuaded by the accumulated evidence, I guess? Which includes the elegance of the laws of physics, the existence of orderly sentient experiences, and the historical evidence.

    I would question why the elegance of laws (if they are indeed elegant, whatever that means objectively), the existence of sentience (as opposed to, say, life?) increase the probability of a god. Then I would question what it is about the Christian story that is so much more persuasive than the thousands of other religious stories humans have told each other.

    Then I would wonder how Don would rule out his god being evil, since this evidence does not. In fact, of course, it equally suggests an evil god as much as God, since the the laws of physics facilitate all the suffering we see (as well as the pleasure), as does sentience.

    The Christian story bears witness to a god of some ill will too, which does not seem to add to the evidence for God, as modern Christians often describe Him (tri-omni-ish).

    So, all in all, I’m left once again interested in and confused by a theist’s reasons for believing!

  17. Magnema says:

    @Daniel: I don’t think nothing is as mathematically complex as you make it out to be. If you make the claim that in order to define “nothing” you need to state that it is not anything. As a counterexample, I say: take the empty set. Is the empty set more complex than, say, the set of every odd natural number? Well, assuming you cannot state either as a pattern (which would reduce to linguistic simplicity, trivially), then BOTH have to be stated by “this is in, this is out” for every possible element… which, of course, is “everything out” for the empty set, and (suppose natural numbers are the only things that exist, for the sake of argument) “in, out, in, out…” for the set of odd naturals. In this case, all sets have the same level of complexity, so this doesn’t give a good definition of simplicity. I don’t think I understand what you mean by “physical simplicity,” either. The standard metrics for simplicity are Minimal Message Length and Solomonoff induction, both information-theoretic, of course.

    As for my own opinions: if there were some evidence for specific ways God interacted with life at a higher level which did not exist at lower levels (i.e., some seemingly non-reductionist effects), I would agree with his conclusions. However, I see no reason to conclude that there exists such evidence, and so I reject that argument. (The “historical evidence,” to say the least, is weak on this point, and I don’t believe it is strong enough to overcome any reasonable degree of skepticism – he might call my a priori probability unreasonably low, but I don’t think it is that unreasonable; I think I just consider the history to be weaker evidence than he does.)

    Another criticism I have is of his lack of belief in “fine-tuning”: yes, it does require a class of models, but there are times when you can reasonably say that any “reasonable prior probability distribution” will not give something which is centered around a specific number to a large number of decimal places unless there is some special attribute of that number (e.g., something can be 1 or 0 to as many decimal places as desired without concern about probability distribution).

    While I disagree with his opinions, I respect the way he comes by them, as it seems to be an honest and logical assessment, albeit (I think) too strongly motivated (leading to flaws in probability assessments).

  18. “the world is the best possible”

    The optimist believes that he lives in the best of all possible worlds. So does the pessimist. 🙂

  19. Magnema says:

    Also, @Ron: First, see this regarding 100% certainty God does not exist (presumably, there do exist possible worlds where God exists); secondly, I believe Bayesian estimates work rather differently than you seem to be discussing them. For standard Bayesian reasoning, you take guesses as to what the probabilities are – based on what you believe to be reasonable assumptions – and come to conclusions from that. You don’t need to know the exact correlation coefficient and slope to know that eating more sugar causes worse teeth, and you can make a guess (albeit one that would have to be modified if actual statistics came up) at a conclusion. In practice, we don’t always have all the numbers, but we can make reasonable guesses. Furthermore, you seem to eliminate prior probabilities entirely, but we need some sort of prior probabilities in order to even reasonably talk about knowledge, or at least to talk about predictive power. Why do we assume that the Std Model Lagrangian is what we observe rather than fluctuating occasionally? Because that is a simpler model. Same problem holds for any scientific theory – they all require simpler theories be given a higher presumption for truth, on some level.

    I agree with you regarding the weakness of historical data and the fact that we should ignore God if there are no testable predictions, but I think you are overly dismissive here. Firstly, you seem to dismiss the historical data entirely – all of the data can, at the very least, serve as (at least) weak Bayesian evidence in favor of (a) God. Secondly, he seems to be making the claim that having a God should have testable predictions in the macroscopic realm – theoretically testable, albeit probably not in practice.

  20. Brad Jackson says:

    To even post an opinion on this subject is tantamount to mental suicide. But, putting aside all of the books and all of the opinions written about all the books on this subject you need to ask questions regarding the makeup of God (not Cover girl or Maybelline ). If your a deity living outside our universe in a multidimensional neighborhood and you want to create a new universe that will create life, but more important, specific types of life, how do you do it.
    You would need to gather together vast amounts of raw energy that you would then arrange in a particular way that would then expand while creating a new spatial dimension. It would have to have been formed in such a way that it would at some point start creating stars and galaxies and solar systems. These solar systems would then have to have been preprogrammed to allow for the conditions of life to emerge. You would have had to arrange things so that when you got down to the creation of life that fields would generate molecules that would also form DNA. You would have to have this preset so you would know the outcome of the genetic evolution of all the life forms and all of the possible outcomes from beginning to end of all of the combinations of DNA. Not just on earth but on every planet of every solar system of every galaxy.
    So then my question becomes, where did God get the information in order to create a universe that would harbor life? Which also leads me down the path that God could have been the left over information of a prior universe after its collapse and reemergence.
    I don’t believe or care for religion in any form. Its ability to turn people into lunatics is on pare with politics. But the question of a creator is interesting but just not practical to ask except as a philosophical exercise. If God created our universe it would mean that he exists outside of it and cannot interact except on some quantum entanglement level.
    OK, so that’s enough of that.

  21. Daniel Kerr says:

    Magnema: I was speaking in a model theoretic or formal language context, but in set theory your example is enough to support my point that that empty set is not any simpler than any other. I think a formal language metaphor is more suited since his argument is more naturally represented in formal logic rather than set theory. You don’t have the empty set in formal logic, there is no empty atom. Otherwise the set theory example is probably a better example than my own to be completely honest.

    And what I mean by physical simplicity is what physics allows to be the most simple. “Nothing” may not be the physically permissible most simple state. I just don’t have a good example to illustrate this. All I can say is we can’t assume “nothing” is the simplest physically permissible state.

  22. “Does God so love the multiverse?”: In Genesis, the first book of the Old Testament, God began a revelation through the family of Abraham, Isaac, and Jacob …, a revelation that said kill gays, devalue women, institute slavery, hate people of other religions, and so forth. (Why should one find value in such a God?) 🙂

  23. Joel Rice says:

    Some prefer ‘design of the world’ and others prefer ‘designer of the world’, but once the design includes minds and civilization looking for the design, one wonders whether the whole point of the universe isn’t “mind-like” in some serious sense. That is not a traditional notion of God but it would not be traditional atheism either.

  24. bostontola says:

    Thanks to Sean for providing diverse viewpoints, and thanks to Don for bravely positing his beliefs. It is rare to get a religious viewpoint from someone who fully understands the science.

    It all reminds me why science works in the first place. The human mind/brain is unreliable. Brains (not just human) are evolved to pull patterns out of it’s inputs. Evolution has made that job so good, that humans find patterns even when they don’t exist (elephants in clouds, faces on Mars, etc.). To combat the false detection probability, we have suppressed the power of authority and demand objective evidence. Dr. Page may want to review that protocol in regards to his conclusions.

  25. Magnema says:

    @Daniel: No empty axiom, perhaps, but (presumably; I don’t actually know much about model theory) there is an “empty model” which makes no assumptions and has no conclusions – i.e., which has literally nothing to it? I would think this could be said to be the simplest model (albeit, obviously, a trivial one).

    As for a set: Sure, if one has all the details, no set holds more information than any other; however, we can define some entropy-like-quantity corresponding to the information it contains with respect to a particular coarse-graining (e.g., if we said “the sets with one thing” vs. “the sets with no things,” the former would have more information because we know the empty set, we do not know the one thing in the set). This would allow you to define a “simpler set” as “one with less information” or something of that nature (granted, you need a precise way to measure that when all entropies are infinite, but that’s not the point), in which case the empty set is still the simplest set (within a particular perspective on the data, of course, but I would argue that’s an intrinsic part of Occam’s Razor on some level).