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
Circular logic:
1. Fine-tuning implies theism because it took fine-tuning to produce men (as well as everything else that exists in the form that it exists in this universe – rocks, trees, beetles, bacteria, etc.).
2. The object of fine-tuning must have been to produce men in the form that men exist in this universe, rather than all the other stuff (although there is much more of it), because men are special and important to the god who produced this universe, because the Bible says so. (Which it would say both if true and inspired by a Holy Spirit and if false and men are arrogant about their place in the universe, but that has nothing to do with the circularity. I just thought it worth pointing out that, just as many Americans think that theirs is the best nation with the best possible form of government, and many Frenchmen think France is the best nation with the best form of government, that men in general tend to think men are the best possible creatures.)
Do you see the circularity now? Without the presumption that men (in just our specific form, bad knees and all) are important to the supposed creator-god of theism, fine-tuning per se offers no support for theism. Which, is to say (since that presumption is the basic tenet of theism) that fine-tuning implies theism because of theism. One could just as well say there is no fine-tuning; things had to exist in some forms for there to be a universe, and we and the rest of the things that exist just happen to have the forms we have, which obviously must be consistent with the universe’s rules (barring the supernatural, e.g., angels and demons which have no respect for the laws of physics or chemisty). If we had some other form, say four arms, and used liquid methane instead of water in our bodily chemistry, theists would probably say that was what god wanted instead.
One could (if one believed our human properties are special on a universal scale,which I don’t) say that fine-tuning is consistent with theism, but not that it is independent evidence for theism. As I mentioned, fine-tuning is also consistent with evolution (with the arrow of causation reversed, to the more humble direction).
This is elementary stuff , far below the pay grades of Dr.s Page and Jefferys and other expert commenters on this thread. We shouldn’t be cluttering up their thread with it. I try not to, and have refrained from clicking “Post Comment” for several half-baked comments, but the evolutionary drive to compete on behalf of my point of view keeps drawing me in.
P.S. Did the Holy Spirit inspire King James to have his translators substitute “witch” for “poisoner” in “Thou shalt not suffer a poisoner to live”, in the King James version of the Bible, or did he do it because he (incorrectly) blamed witches (midwives) for causing his son to be born with syphilis? If the latter, how do we know which parts were inspired and which parts were not?
No need to answer – just a minor example to show why “inspired by the Holy Spirit” is an assertion that does not inspire confidence in some of us, containing as it does another hint of circularity.
Has CPT been reconciled with the second law of thermodynamics? Or is physics still in ‘contextual nibbles’? Do the experts know?
Jim V
I have been looking again at Ernst Mayr ‘What Evolution is’ and I still don’t see much. All looks circular/inconclusive to me.
Hi everybody!
I’ve been closely following the debate in this comment section. Being a devote christian, and a physicist, I find this debate fascinating, and, regardless of the outcome, I think it is a worthy debate to have, if for no other reason, but to gain excellency in the process. Now, I don’t think that anybody is particularly keen on giving up his or her position in this debate. I think it is a highly emotionally charged topic, even in this medium. We’re all human, after all. Even so, I think that change *is* possible, in either direction, given the right input.
Having all that in mind, I’d like to try and stir up the mindset on both sides (see what comes out).
Please consider the ‘Cognitive-Theoretic Model of the Universe’, by Christopher Langan. I’ve read it, and it is clear to me that it contains ‘new’ information, not yet expressed in this debate, about the nature of reality, etc.
http://www.megafoundation.org/CTMU/Articles/Langan_CTMU_092902.pdf
Wikipedia writes
“The CTMU has gained both praise, and controversy in the scientific community. Robert Seitz, a former NASA Executive and Mega Foundation director stated “every physicist is inundated with amateurs’ ‘Theories of Everything,’ but Chris’ CTMU is very, very different”.[14] On the flip side, the CTMU theory has been criticized for its use of convoluted language. Langan’s use of terms he has invented (or redefined) has made his exposition obscure, leading some to question his honest intention to make himself clear.[15]”
Josh, that helps a lot, thanks! I was kind of also hoping that there’d be some published work – like Stephen Hawking’s A Brief History of Time which explains about the psychological and thermodynamic arrows of time – which covered more of the above. The bit of it that Hawking covered, helped me enormously.
Bill Jefferys
“Simon, then I do not understand your argument. Please restate it more clearly.”
Just prior to the place I picked up, you used a three point argument to attempt to prove that the anthropic principle supports atheism, at April 7 at 8:27 am. Your first two statements gives room for the theistic argument to manifest in a particular form. That would be by means of testing for adherence to parameters which support a deterministic naturalistic universe resulting in us and looking for any violations. You are inferring that there is no need for tweaking of the parameters/physics if the anthropic principle applies. I agree, provided you acknowledge that you are only testing for ongoing interventions by God that manifest as violations of the parameters/physics used. Your third point, given the condition I just stated, I agree with also. Given an arbitrary prior of 0.5 for theism manifesting as parameter/equation deviation, we would build a case for no external agency by this mechanism.
However, I would also say one may argue from the perspective of ‘creation’ of a single universe, which is what theists do here of course. We are testing for the likelihood that our parameters were chosen to get the universe to produce human life. We can start with the same arbitrary prior. At each successful waypoint towards the facilitation of human life, our confidence grows that the parameters have been selected for the outcome. We have got a high confidence that the physics of the creation process has fortuitous parameters for a human outcome.
I am sure you understand all this. You then said, “Simon, your comment ignores the point of my last posting, on the need to condition probability statements on all relevant prior information.”
You are presumably referring to “In the case of anthropic arguments, you cannot ignore your own existence as an observer.”?
I replied:
“My potential future existence is neutral regarding theism in the prior when projecting forward in time.”
I think I would be agreeing with you by saying that Bayesian arguments for massively open information scenarios are extremely hard to quantify, and anything with a large bearing on the prior needs to be included. I feel the real problem is that we are awash with subjectivity before we start, so we need to state our starting assumptions or use an arbitrary prior of 0.5. Even then, as your scenario shows, we need to state what that 0.5 is for, precisely. With the first scenario, set forth by yourself, we are starting by acknowledging our own existence. This is implicit in the definition of what we are calculating. We are calculating from the premise that humans came about. In the second, set forth by me, we are not making any assumptions about our existence because we are trying to see how likely it would be. The fact that I am actually here doing the thought experiment is not a reason to include that into the starting conditions of this particular thought experiment.
Josh-
“This is how much of our common sense about what is “logical” is formed and thus goes to show that much of what we think is “logical” is observed in nature. Such discussion is relevant because, in some sense, the recognition can be used to support a naturalistic worldview.”
This fascinating discussion made me wonder. If a un-repeatable, illogical , un-explainable event is observed , can the observer not claim un-natural reality? And can that observer not use it legitimally to support his non-naturalistic worldview?
Don Page says:
“First, Jesus is the only religious leader I know who claimed to be the Son of God and lived a life that supported such a claim”.
The meaning of the titles “Son of Man” and “Son of God” is much debated by historians. It is unsure that he claimed to be the Son of God. And what is the meaning of Son of God? Again, hotly debated topic.
———————–
“Second, in the time of Jesus that was before the printing press and the web, so that people did not have an easy way of making and rapidly copying physical written records, people were much more skilled at remembering things mentally and passing them on orally. So I do not see that method of passing on the eyewitness accounts of the Resurrection as being much more unreliable than current methods that give only very weak support for claims such as UFO’s, government conspiracies, bigfoot, etc.”
The great difference is that is was almost impossible to correct an error or an intentional change in the story. Nowadays investigations about government, UFO’s are possible thanks to fast and safe travels, internet, videos, people that can dedicate their lifes to debunking… At that time, if an apostle said A and the listener changed it to B, it was very improbable for the apostle to have any way to correct the listener, since he will probably never see him again. So stories got changed, embellished and invented all the time. Not just for Christianity, also for Buddhism, Hinduism… Just look at the differences between John and Mark!!
—————————–
“the hypothesis of the Resurrection seems to me to be the simplest explanation for the historical reports if one also makes the wider hypothesis that a God exists who might want to resurrect someone He considers very special.”
Again I may ask, like in my previous post, how do we possibly know God’s intentions (especially his ideas about the resurrection of people) and make claims or evaluate probabilities about it?
Circularity
In JimV’s much elaborated response of April 7, 2015 at 11:12 pm, I see his point that Fine Tuning is circular than the one sentence of April 7, 2015 at 3:51 pm comment.
It seems to me that part of this argument is how does one account for fine tuning with all its finely balanced constants or parameters. To borrow John Leslie’s example, if one faced a firing squad and survived, one still must explain if the execution was a “fix” or a “put up job”.
Conditional on theism — no circularity here — I believe that God could have arranged matter for life to exist, so that the probability He would choose natural means seems to me higher than the probability that a single naturaltic universe and randomly chosen constant will somehow produce life. I read that Roger Penrose calculated there are 10 to the 10th all to the power of 125 number of universes and only 1 would have the order as ours.
JimV may not need to the aid of Post Comments because he’s an expert on this topic but you can bet there are many hundreds of readers who care not to comment in this blog and would find the sites useful. I dare say, even for this small sample of writers. So let’s be charitable to them and let’s be inclusive.
I really liked Freeman Dyson’s interview. But’s that my bias.
@Josh:
“logic” because everything abides by these rules (disregarding some mystical interpretations of quantum mechanics). —-what we think is “logical” is observed in nature.”
I have to disagree. As you probably know, from the results of Bell’s theorem and subsequent experiments, majority of physicists are led to the conclusion that “the particles are in some kind of suspended state devoid of any specific properties until they are observed.” If this is not mystical then I do not know what is mystical. How can you ignore conclusions of the most successful theory of science? As far as I can tell this conclusion is forced on us and we have to accept it even kicking and screaming!! You cannot use “logic” when it is convenient for your beliefs and ignore “logic” when it runs counter to your beliefs.
Kashyap/William,
I am not taking up this argument as it is not necessarily mine and somewhat off-topic. My comment was in response to Paul’s above asking for an explanation of a bit he cited from Don. Do remember though too Kashyap that physicists widely disagree how how to interpret QM (there’s quite a few ontologies, so it’s best not speak as if the mystical has been ‘shown’ true yet).
———–
Paul,
Sean Carroll writes on this. You might search for the topic in some of his blogs or check out his books.
Josh/ Kashyap/William:
On a closely related topic. What is “evidence”? Is it only derived through the scietific method? Are other kinks of evidence inadmissible in the search for understanding or for the basis of belief?
I think it’s germaine to this post.
As it seems a bunch of points are cropping up here, I think I’d like to try and highlight the base of the skeptical argument a bit. Here’s my take on the summarized version of what’s been said that runs contrary to Don’s ideas in plain terms:
———
Don has argued that it’s possible that god provides a simpler explanation of the universe than a purely naturalistic one. He has also argued that, given a type of theism as a prior, a Bayesian analysis might support Christianity (a la the resurrection).
What Don hasn’t done is show that his theism is simpler than a naturalistic view. He also has not provided such an analysis that either shows the specifics of Christianity must flow from his prior or that it can be meaningfully calculated to any confidence interval.
Therefore, Don’s arguments may provide that our world is consistent with his theism, but it does not offer any excluding evidence to cause one to prefer his theism over other theisms, naturalism, etc. Rather than employ hard skepticism then to his view and refrain from accepting it or simply claim only agnosticism towards it, Don puts his faith in this rather large and impressive claim (Christianity).
Don attempts to provide justification for his faith by suggesting that the resurrection would be likely in light of the prior of his theism, and also that theism would seem likely given the resurrection. Noting, as above, that he has provided neither the evidence that his theism must be simpler nor the exact Bayesian analysis linking it to Christianity (as well as evidence of the resurrection), we must acknowledge this argument as clearly circular and his noting of priors realistically only tantamount to biases.
Unless then Don provides some other strong reason for his theism, his faith must be entirely preferential rather than evidentially based. Although we are certainly welcome to accept things individually with varying personal requirements of evidence, many of us here would argue that such faith is misplaced and can lead to willingness to accept views that are untrue, harmful, or hinder personal or social growth.
———
Don,
I hope you’ll forgive me for listing this bluntly and impersonally, which was done only for the sake of clarity in discussion. You’ve been very gracious in the discussion so far, which is not only an impressive show of character, but also something quite appreciated.
Josh writes April 8, 2015 at 9:55 am: “Don has argued that it’s possible that god provides a simpler explanation of the universe than a purely naturalistic one. He has also argued that, given a type of theism as a prior, a Bayesian analysis might support Christianity (a la the resurrection).” That a good synopsis and it focuses the debate.
Here is one view from Professor Aron Wall (who in the “same” intellectual league as Professor Carroll and Prof. Page.) I prefer to quote Prof Wall entirely so nothing is taken out of context. Professor Don made reference to Professor Aron in a previous post; also for the broader community of readers looking for information and clarity. I owe it to them as well., Sts Don and Aron are of the same mind on this subject, in my view, and Don might want to weigh in here.
Beginning of quotation mark:
“Putting everything together, I have argued—using plausibility arguments, not strictly deductive proofs—that it is reasonable to believe in a metaphysically ultimate being, and that given the reality of Ethics or Consciousness, it is probable that it is more like a mind than like a set of equations. More specifically, my arguments pointed to just one eternal God, existing necessarily, who is all-powerful, all-knowing, and good, who is the source of all other things, yet is distinct from them, and who appreciates mathematical beauty, conscious life, and ethical behavior.
Of course there are a lot of mysteries left in this view. Even though God is supposed to be the explanation of all other things, we cannot predict, from this information alone, exactly which laws of physics God would select, nor whether he would intervene in the Universe thus created in other ways. Not sharing the divine knowledge about what is best, we have to make additional stipulations about the world he has created, adding to the complexity of any specific Theistic worldview.
But then again, Naturalism by itself cannot tell us either (apart from experiment) which specific laws of nature to expect. All views contain a certain amount of irreducible mystery. The difference is that Naturalism hides or denies the mysteries, and pretends to solve problems that it cannot possibly really solve, while Theism puts them up-front and center and does the best it can to fit them into a consistent picture of the world.
It does not matter so much whether you are convinced that my conclusions have to be right. Maybe there were several places in the argument where I selected one of two paths, but you think it was a toss-up, or that the other way was somewhat more plausible. That’s part of the hazards of armchair reasoning. Personally I am primarily concerned with the arguments for Theism as a prelude to Christianity, which is founded on the Resurrection of Christ and the testimony of God’s Spirit, not philosophical discourse. But plausibility arguments still have their place. If you are thirsting after goodness and beauty and meaning, and if you learn that there could well be a fountain capable of slaking that thirst, shouldn’t this increase your incentive to search for it?
A purely intellectual philosophy can only get you so far. Actual religion involves opening yourself up to the divine being, over a continued period of time, allowing God to get hold of you. Any approach must be by his initiative rather than yours, but your attitude can determine whether or not you are receptive to his advances. Without this, philosophy is sterile. If it advances only to savoir, conceptual knowledge, it might as well have remained atheistic. All of these philosophical arguments are only there to help you make further steps, to connaître or knowledge by acquaintance. Arguing for the existence of the Good is one thing; tasting the reality of the Holy is another.
When that happens, the purely intellectual arguments—and the doubts which are a necessary corollary of any honest attempt to evaluate them—can be kicked aside like a ladder that has served its purpose, and replaced with something far better.” End of quotation mark
http://www.wall.org/~aron/blog/fundamental-reality-xiv-conclusion/
TY
I like that quote, thanks as I never got round to following him up.
Bill Jefferys (April 7, 2015 at 9:49 am) argued that “it is absolutely necessary to condition all probability statements on any relevant data that is already known as prior information before the experiment, whatever it is, is carried out.”
However, in his own paper that he cited, at http://bayesrules.net/papers/OldData.pdf, Bill noted, “As Jaynes ([3], p. 89) points out, probability theory, like logic, is time-independent. All of the relationships in probability theory are logical relationships and have nothing to do with the order in which we happen to learn about the evidence or write down the Bayesian equations. … it does not matter when we have actually observed E; the relationship between the two is purely a logical relationship, and the quantities that go into the calculation (likelihoods, priors) will be the same, regardless of when E is observed.”
Therefore, we don’t actually need to conditionalize upon something like life as Ikeda and Jefferys did, even though we learn of its existence before we formulate probabilistic arguments. Indeed, if we were forced to conditionalize upon all that we know, we could not calculate the probability that any hypothesis assigns to anything that we know, so we could not calculate the likelihood of any hypothesis based on anything that we know.
In this way Ikeda and Jefferys’s criticism of fine-tuning arguments were incorrect. Although I pointed this out in one of my recent comments before reading the critique of Luke Barnes, it was encouraging to read this critique that independently brings out this same point much more eloquently that I can by a greater expert in the fine-tuning arguments than any of us engaged in the current debate on this blog.
Simon,
Professor Aron wall is right up there: he knows his physics and theology (even history and philosphy). No wonder his blog is called Undivided Looking. — that whole view. Is he any less rigorous in his science? Hardly.
Hope readers check his blog posts and the recent one on the Fundamental Entity ..worth the effort.
I maintain there is no conflict between sceience and Faith.
Don writes on April 8, 2015 at 11:50 am
“In this way Ikeda and Jefferys’s criticism of fine-tuning arguments were incorrect. Although I pointed this out in one of my recent comments before reading the critique of Luke Barnes, it was encouraging to read this critique that independently brings out this same point much more eloquently that I can by a greater expert in the fine-tuning arguments than any of us engaged in the current debate on this blog.”
That’s right Don. I read Barnes’ critique and that is what motivated me to ask Bill in a recent comment what he thought of the Two-part critique. I too thought Luke Barnes got it right on all the technical and methodological points on Bayesian Analysis application to the Fine Tuning hypothesis
Sorry, Don, but you totally misinterpret the need to condition on relevant data. You need to read what I wrote again.
I’ll put it another way, maybe this will help.
Here is the data:
D=”We observe that our universe’s physical constants lie in the anthropic zone”
H–>D; if “physics is all there is”, then it is a necessary consequence that we will observe that our universe’s physical constants lie in the anthropic zone.
In the language of probability theory, P(D|H)=1. There, I’ve removed the conditioning on our own existence by being explicit about what the actual datum we observe is.
Barnes’ datum isn’t that, it is
D’=”The physical constants of some universe lie in the anthropic zone.” Clearly, if the physical constants are chosen randomly, it isn’t necessary for D’ to be true for a randomly selected universe, I understand that.
But D’ isn’t what we observe. D is what we observe.
Barnes’ argument is basically a frequentist one, not a Bayesian one, and it is incorrect for the same reason that many frequentist arguments, especially in hypothesis testing, are incorrect.
In particular, Barnes’ argument violates the likelihood principle.
“All of the relationships in probability theory are logical relationships and have nothing to do with the order in which we happen to learn about the evidence or write down the Bayesian equations.”
Is there not a difference between time as a variable in the scenario we are examining, which has implications for the logic associated with the overall scenario, and time in the sense of the sequencing of the Bayesian process?
TY
I believe the conclusions of the scientific method correctly applied are all part of logical truth for the God I have faith in.
Bill Jefferys (April 8, 2015 at 12:11 pm) wrote, “H–>D; if “physics is all there is”, then it is a necessary consequence that we will observe that our universe’s physical constants lie in the anthropic zone.”
I disagree. If “physics is all there is”, then it is a possible consequence that we not exist at all and hence not observe that our universe’s physical constants lie in the anthropic zone.
But Don, there is no possibility that we do not exist. That’s the whole point! We do exist. Just look at your hands!
Bill, I am just noting that one can entertain hypotheses that do not assign unit probability to our existence, just as we can for other observations we make. If we had to conditionalize on all that we know, we could not use any hypotheses to calculate the probabilities of anything that we know (any observation that we make). Since the probability of an observation given a hypothesis is the likelihood of that hypothesis (relative to that observation), we could then not calculate the likelihood of any hypothesis.
That is, a Bayesian analysis requires us to be able to consider at least something that we know not to be conditionalized upon. Then one can consider the case in which that something is our existence.
No, no, Don, you are committing the same mistake that Barnes makes. You do exist, which is why you have to take this into account when you decide to find out whether the physical constants of our universe are consistent with our own existence.
Have you read Brandon Carter’s paper, where this was all introduced? If not, you should.
If we were to find out that those physical constants are inconsistent with our own existence (assuming “physics is all there is”) then that would at one stroke prove that “physics is not all there is”, and that some sort of god was overriding what physics says and allowing us to exist despite this fact.
It cannot be the case that our observing that the constants are right, and observing that they are not right, can both support theism. That’s an elementary theorem of probability theory. Since it is plainly evident that observing that they were wrong has to mean that “physics is not all there is” it is therefore the case that observing that they are right must undermine “physics is not all there is”.
After all, the whole point of claims of miracles (e.g., the resurrection) is to prove theism by demonstrating things that cannot be explained if “physics is all there is”.
Your counterfactual speculations are entirely irrelevant to this question.
No one suggests that you have to condition on all you know, only (as I clearly stated) that you have to condition on all relevant prior information, that is, information that can affect the data we are trying to observe. Surely you do not do this when doing physics!