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
Don,
Sure, if you start with a high prior for naturalism you will tend towards naturalistic explanations. Same with theism. I wasn’t contesting that. I think I’ve argued previously that either of those would be poor priors anyways, but that’s beside the point.
I was contesting your generalized claim that the philosophical difference in priors between atheists and theists were “naturalism vs theism” specifically. I was positing instead that the key difference is epistemological– the prior of atheists is high skepticism (a sort of low prior probability applied to all claims) with the way of raising a claim’s likelihood being evidence (and lots of it). Thus the real and running philosophical difference really being that atheists are, at least on the matter of supernatural entities (though if they want to be consistent, it should be on everything), employing higher skepticism and demanding more evidence.
That’s only if you want to generalize though (which you seemed to be in a previous comment).
Josh,
Are you just saying that a skeptic would not believe in anything unless he or she thought the probability were very near unity?
For example, I might estimate that my posterior probability for theism, given the evidence I am aware of, is around 98% (and say 96% for the specific Christian form of theism, with Jesus being the Son of God). Would you say that if I employed high skepticism, I should say that I am an agnostic rather than a theist?
….Granted I could see how it might be hard to see atheists as not having a prior for naturalism if you’re on the other side of the fence, so I’m probably due a little more elaboration.
Atheism comes in a variety of flavors. For instance, you have those who explicitly claim god is false (they know there are no gods), and those who implicitly claim god is false (they feel there is not sufficient evidence to justify a belief in god, at least yet). You could say the same thing about naturalism. You might implicitly or explicitly claim naturalism.
Don, if someone is explicitly claiming naturalism, you may be right that they are starting with it as a prior, are in an unfortunate way biased against possible evidence that might support a claim of divinity.
But there’s the other side to it, which arguably is true of many atheists (even some of the more strident public figures), which believes in naturalism simply because that’s the only thing they feel they currently have reason enough to justify. They wouldn’t start with the prior of naturalism, but rather start with a prior of skepticism. They might then ask “What kind of things exist?”. Well, certainly natural entities (those obeying the laws of physics, etc.) do. We have plenty of evidence that natural entities exist, and moreover that historically, all cases potential non-naturalness have later found to be very natural after all. They might then ask “Well, do supernatural entities exist?”. One could come to one’s own conclusion, but surely at least we’d acknowledge less evidence of supernatural entities.
You might call the naturalism that comes out of this “implicit.” That is, when we say “the only things that exist are ‘natural’ things,” we mean that those are the only things which we currently feel justified in believing to exist. This naturalism then isn’t necessarily a prior, and doesn’t necessarily affect the posterior probability of theism in any way.
Since that’s possible, and arguably held by a swathe of the nontheists out there (and us in the comments), that’s why I found it super presumptuous to think the difference in conclusions you see here amounts to priors of naturalism vs theism explicitly (and argued instead it’s epistemological differences in degrees of skepticism).
Don,
I was elaborating a bit more while that last reply went up.
I would probably say that if you were employing higher skepticism you would at least claim instead to be an agnostic than a theist. I wouldn’t make so bold a claim as saying the skeptics require a probability near unity though and would admit that probability one personally demands is very, very subjective. What I would say at least is that atheists are probably less willing to commit and requiring a higher number. I would also argue though that the way in which atheists and theists get that number tends to be different to (we require more evidence to make our percent confidence raise a unit percent), but taking that point further might be getting into unnecessary details.
Either way, I would cede it is a relative matter.
…Actually, I think I misinterpreted your comment.
I’d probably buy into something with as high a confidence of 96 or 98, sure. I think how close one expects to be near unity would be subjective, though I think the atheists would be more skeptical and require even closer to unity, culturally, than the theists would. More importantly (despite what I said in my last comment), I think it likely that the significant difference comes from that atheists wouldn’t even have that high a posterior probability in the first place though–as they require more evidence to raise their posterior probability a unit percent due to having an extremely low prior probability for all claims via skepticism.
This comment is a much better depiction of my point. Please forego the previous.
Josh,
Prior probabilities, like all probabilities, should add up to one, so one does not really have a complete set of prior probabilities if all of a fixed finite set of claims are assigned extremely low prior probabilities. However, perhaps you are advocating assigning only extremely low prior probabilities to definite claims and leaving a most of the total unit prior probability for unspecified claims. But then it would not seem fair to say that the unspecified claims are naturalism rather than theism; one is then just being agnostic about what are the possibilities assigned the bulk of the total prior probability.
I don’t see any argument that agnosticism is incoherent, but if one does want to choose among some finite set of options (such as naturalism and theism) by their posterior probabilities from a Bayesian analysis and thinks the probabilities of other options can be ignored, it seems to me that one is forced to assign prior probabilities to the options being considered that add up to nearly one (up to the total prior probability for the options one is ignoring).
Don,
I admit that I’m cheating. My “prior probability” is not really a prior in the Bayesian sense (or really a numerical probability at all), but rather an intrinsic bias. I was only discussing it that way so as to hopefully make it more relate-able as, from what we might garnish in the comments, you find that more palatable.
Rephrased, the point was that many atheists (arguably both here and culturally) aren’t doing what you seemed to claim as the key present difference (your claim being that we assign a high prior for naturalism thus affecting posterior probabilities for Jesus). I’m say that our epistemological methods (how we get at knowledge) is just completely different— We’re highly skeptical of all claims, and only those with high degrees of evidence survive. The reason then that belief in natural entities survives is because there’s mountains of evidence for them. The reason belief in supernatural entities doesn’t is because there is at least less evidence for them, and we, admittedly subjectively, have set the bar higher than what the amount of supernatural evidence can reach (though hopefully we did this before we began our own personal argumentation).
If it seems I’m ignoring bits of your response, it’s just because I’m assuming those bits are keyed on my position really being a bayesian discussion, which it’s not. Which is, in fact, my point, that for most of us it isn’t, and therefore that’s likely not a good general description of the major epistemic difference for the theists/atheists here.
I have been reading these debates with lot of interest. My (theistic) take on ideas of divinity has always been that it is not a matter you can prove (or disprove) with our day to day (classical as it is) logic. My guess is that after 682 comments, number of readers who have changed minds is close to zero. But I am willing to be surprised. If you changed your mind about resurrection and theism after reading these posts please say so! I would like to know.
Josh,
When your write, “We’re highly skeptical of all claims, and only those with high degrees of evidence survive,” I would think that one could cast this into a Bayesian framework (which is very general) by saying that you assign very low prior probabilities to all claims (or at least to all specific claims, perhaps leaving vague claims such as “none of the above” to pick up the remainder of the unit total for the prior probabilities), and then only the ones with relatively high likelihoods survive.
But let me list a number of claims (mostly not mutually exclusive, so these are not all for alternative hypotheses, and of course none of these claims are complete hypotheses for the entire world, and neither do these sample claims make up a full deck of all possible claims, even though I am giving 52 of them). Then I might ask you of which ones you are highly skeptical:
1. One’s present sentient experience (conscious perception, all that one is consciously aware of at once) exists.
2. One’s past sentient experiences exist.
3. One’s future sentient experiences exist.
4. Other people’s present sentient experiences exist.
5. Other people’s past sentient experiences exist.
6. Other people’s future sentient experiences exist.
7. One’s body exists at the present.
8. One’s body exists in the past.
9. One’s body exists in the future.
10. One’s body exists in the infinite past.
11. One’s body exists in the infinite future.
12. An external physical reality exists at the present.
13. An external physical reality exists over a past time period.
14. An external physical reality exists over a future time period.
15. An external physical reality exists over both past and future.
16. An external physical reality exists over just a finite past and a finite future.
17. An external physical reality exists over just a finite past but an infinite future.
18. An external physical reality exists over an infinite past but just a finite future.
19. An external physical reality exists over an infinite past and an infinite future.
20. A definite single history exists for the universe.
21. An ensemble of more than one definite histories exists for the universe
22. A quantum description that does not include definite histories is true.
23. A single sequence of sentient experiences exists for each person.
24. Multiple branching sequences of sentient experiences exist for each person.
25. No definite persons exist within the universe with each having his or her own definite sentient experiences.
26. Laws of physics describe the evolution of an external physical reality.
27. Laws of physics describe the initial conditions or other boundary conditions of an external physical reality.
28. Laws of physics describe how sentient experiences are related to an external physical reality.
29. Laws of physics are deterministic for the evolution of an external physical reality.
30. Laws of physics are indeterministic for the evolution of an external physical reality.
31. Laws of physics determine sentient experiences from an external physical reality.
32. Laws of physics have sentient experiences and an external physical reality both act on each other.
33. People’s actions are determined, but they often act in accordance with their wishes (compatibilitist free will).
34. People’s actions are not determined, but rather their acts exhibit incompatibilist or libertarian free will.
35. The ultimate causes are only impersonal laws of physics.
36. The ultimate causes are only impersonal laws of physics and quantum randomness.
37. The ultimate causes are only impersonal laws of physics and libertarian free will of sentient beings.
38. The ultimate causes are only impersonal laws of physics, libertarian free will of sentient beings, and quantum randomness.
39. The ultimate cause is only a personal God.
40. The ultimate causes are only a personal God and libertarian free will of physical sentient creatures within the universe.
41. The ultimate causes are only a personal God, libertarian free will of sentient creatures within the universe, and quantum randomness.
42. The ultimate causes are only a personal God and other uncreated spiritual beings.
41. The ultimate causes are only a personal God and other created spiritual beings.
42. The ultimate causes are only a personal God, other uncreated spiritual beings, and other created spiritual beings.
43. The ultimate causes are only a personal God, other uncreated spiritual beings, other created spiritual beings, and libertarian free will of physical sentient creatures within the universe.
44. The ultimate causes are only a personal God, other uncreated spiritual beings, other created spiritual beings, libertarian free will of physical sentient creatures within the universe, and quantum randomness.
45. God is only one Person in the sense that Jesus is not the Son of God as traditional Christianity claims.
46. God is two Persons: God the Father and God the Son (Jesus Christ), but not God the Holy Spirit.
47. God is three Persons: God the Father and God the Son and God the Holy Spirit.
48. Humans live only once and not after they die.
49. Some humans live forever in Heaven and the remaining humans live forever in Hell.
50. Some humans live forever in Heaven and the remaining humans are annihilated.
51. All humans live forever in Heaven and none ever experience Hell.
52. Some humans are disciplined in Hell, but eventually all humans accept the redemption of Christ and live forever in Heaven.
Most of us are skeptical of many of these claims (particularly since many pairs seem to be mutually incompatible), but are the skeptics that you refer to really highly skeptical of all of these claims? I would have thought that most people would at least implicitly assign different degrees of plausibility (or different probabilities, whether or not one could give numerical values for them) to these different claims. Almost all of the claims (except 1) involve extrapolating beyond what one directly knows, so I would have thought that the degrees of plausibility one assigns to them would inevitably involve prior probabilities, at least implicitly.
For example, I do not directly know for certain from my present sentient experience that their memory components imply that I actually had past sentient experiences, but it is certainly a simple hypothesis (which our minds seem to make quite automatically, effectively assigning a high prior probability to it) that these memory components of my present sentient experience were laid down by past events during which I had sentient experiences of those events. I don’t see that this implicit assignment of a not low prior probability to the hypothesis of past sentient experiences is qualitatively enormously different from assigning a not low prior probability to the hypothesis that the ultimate cause is a personal God.
Don,
You could cast it in a Bayesian light, yes. If you really want me to, I can try and think along those lines, though I didn’t feel it necessary.
I think unfortunately I have a boring answer for you though– yes, when actually making truth claims, we should be skeptical of everything on your list. You could challenge me on that, but I’m not sure I’d see the benefit as the tangents could be quite numerous, and if you caught on somewhere I wasn’t applying skepticism to an ontological truth claim, I’d simply have to say you’re right and work on it.
Although I think dropping the skepticism bar for theism would indeed be a bit worse than some of the postulates you listed since theism is probably going to lead to even more truth claims and is dependent on many as well… still, I don’t know how strongly I would take up that point as I don’t think it matters. So there’s my boring answer again– if you’re making an objective claim about reality, be skeptical, period.
Josh,
I admire your consistency in trying to be skeptical of all truth claims. I myself am skeptical of many of the claims on my list that most other people would accept.
However, one of my points is that theism is certainly not the only claim that one can be skeptical about. If one takes an attitude of radical skepticism of all truth claims, there are very many such claims that not involving theism that most people just assume without questioning.
Since I asked Josh May 5, 2015 at 10:56 am which ones of my list of 52 claims he is highly skeptical, I should give my own answer.
The claims that I tentatively believe in as part of my working hypotheses are the following: 1-9, 11-15, 19, 22, 24, 26-29, 31, 33, 39, 47, and 52. (However, even for those of these that refer to time, I should say that I am skeptical of time as being fundamental, so I only believe those statements to the degree that I take time to be an approximate emergent phenomenon.) Also, I should point out that in view of the lottery paradox, although I think each one of these claims is more probably true than false, I do not believe that the conjunction of all of them is more probably true than false; probably I am wrong about several of these claims, but the falsity of some of them would not imply the falsity of all of them.
Don,
You’re right. People are often not consistent in their skepticism, atheists included. Things people think they hold as only functionally-held considerations (not objective claims) often unfortunately are argued as if presumed objectively true. We should stop that, hah.
I don’t think you ceded to something you should have though– that hard skepticism in this manner is a major epistemic component of what’s often seen in the atheist philosophy (though of course this varies between individuals), and so you can’t boil the cultural difference down to a difference in the priors you listed. That was my whole point jumping back in after all, as I found it a bit presumptuous.
Josh,
I still don’t understand the basic difference between “hard skepticism” and (at least implicitly) assigning low prior probabilities to what one is skeptical about. Maybe one does not think in terms of probabilities, but if one is conclude with some idea about posterior probabilities, it seems to me that one not only needs likelihoods (the probabilities of the observations or data used to test the hypotheses, given the hypotheses) but also prior probabilities for the hypotheses.
Perhaps you should explain to me how you are being skeptical without implicitly assigning low priors.
Don,
I’m under the impression that when you’re talking about theists and atheists using prior probabilities and posterior probabilities you were implying Bayesian thinking because so much of the past dialogue has been that way….
If that’s so, then the mere fact that many atheists indubitably aren’t taking the Bayesian route to their conclusion in their heads should really have been enough to cause you to pull the generalization.
If you’re not necessarily taking a specific formalization of working through probabilities, then yes, we can call being skeptical assigning low priors…. though the term betrays itself more to Bayesianism, and to me it feels better discussed as a scaling factor. I don’t see the relevance though as my beef was that you were pointing at naturalism and theism specifically as if there were something unique happening there with setting priors. For the consistent skeptic though, there’s nothing unique about either (at least initially), and so pointing at two specific “priors” as the issue doesn’t best paint the picture.
I feel like I’m talking in circles on this though and something’s not clicking… when you said it came down to those priors, maybe you were making an objective claim rather than one about how the “two sides” have been operating (a cultural one)? If you were making an objective claim, then we’re just talking past each other as I would have unfortunately misread you. If it’s the other case, then I really don’t see how you could still hold to your generalization.
Dear Don
I found your 52 points very thought provoking and leaving me thinking where I stand and how to express it. Some of the questions Paul Wright asked earlier led me to consolidate my thinking further.
You are starting from the physical and science-philosophical viewpoint, as befits a physics professional. I would say that the Bible is starting from a relational and revelational viewpoint, and that perspective is more fundamental, because it is rooted in the immutability of God’s character. I don’t necessarily see physics as immutable. We may be seeing only one manifestation of a possible immutable underlying physics framework, or perhaps our physics, at deepest level, is just a tentative and temporary arrangement for the expression of reality as God sees and defines it.
As befits this relative value weighting, and as I have already stated in previous comments, I see human choice as an absolute reality with absolute consequences. I believe however that the scope and therefore consequences of that real ability to choose is constrained by the sovereignty of God. God defines the context in which our freewill operates. In other words, God does not give humanity decisions to make that are too far reaching in their consequences at present. However, insofar as our freewill has been granted, the outcomes of are respected by God and his universe, and become reality for all.
Put another way, I see the created order, including the physics we see, as less fundamental, and more a servant to the purposes of God, which are essentially about sentient relational realities. I think God might re-frame physical realities profoundly at various times and yet leave person-hood and our relational facets pretty much intact.
If I am correct, we may be making a mistake in trying to extrapolate back into previous epochs using the currently manifest laws of physics, even if fully uncovered.
This position will probably look defeatist to many, because if I’m correct then I’m saying that we just cannot know the past and the future because there could be hidden discontinuities in the Divinely-granted context of human existence. However it is illogical and misleading to ignore possible limits inherent in ones methodology, whether it looks defeatist or not.
My summary relating to points concerning physics would therefore be;
‘Laws governing the fabric of our experienced reality (which we classify as ‘physics’), even if discovered completely, are not necessarily immutable, but are readily and easily re-scripted by an infinite God to better serve his relational purposes’.
I therefore do not believe in a finally deterministic-by-physical-law universe or a many worlds scenario.
Do you feel we know enough to falsify my statement?
Josh,
If I put your discussion into Bayesian terms (the only ones that I can see how to use to estimate posterior probabilities), then it seems clear that what conclusions you get depend on your prior probabilities (even though you may not be realizing you are effectively assuming something about the priors). But if you are saying that what you are doing cannot be put into Bayesian terms, I don’t know what you are doing. You would need to explain to me in much more detail what approach you are taking in order for me to understand it, since I don’t yet.
Don,
We must be talking past each other here as I have no clue how to respond to your last comment (I’m not even sure if I disagree with anything in it).
Let me just ask you this– when you said it came down to the setting of priors of naturalism vs theism, were you either:
A) Saying the truth one should perceive comes down to how you set those priors
or
B) Saying that’s the primary cultural difference in what the two sides (nontheists/theists) are doing
I’m arguing you can’t say B (because there’s a bigger picture afoot about what the nontheists are doing in their own, subjective minds that’s different). I’m not challenging you on A (any challenges I had on that were way back earlier in the comment thread and have been previously exhausted).
Let’s get that clear before I respond as, if you’re saying A not B, then I wouldn’t have anything to say really.
Simon Packer, I agree with your statement, ‘Laws governing the fabric of our experienced reality (which we classify as ‘physics’), even if discovered completely, are not necessarily immutable, but are readily and easily re-scripted by an infinite God to better serve his relational purposes’. I do indeed believe that God re-scripts the laws to perform miracles, in particular the Resurrection of Jesus Christ.
However, I do believe that the laws of physics are deterministic in the sense that when God does use them, they completely determine what occurs within the universe. Of course, I believe that it is God who is the ultimate cause and determiner of everything. That is, I take creation from nothing in the strong sense that God alone completely creates and determines everything concrete (not logically necessary) other than Himself. This belief does have the implication that no creatures, such as humans, have libertarian free will, since free will choices would be concrete entities not created from nothing by God.
Dear Don,
On the distinction between Laplacean determinism and quantum indeterminacy, William Craig wrote “Quantum indeterminacy is proof positive that modern science is not based on determinism.” (A Reasonable Response, William Craig, pg 194). He goes on to elaborate: “The Laws of Nature describe the behavior of physical systems in the absence of any supernatural intervention.” Similar point you make and specifically: “I do indeed believe that God re-scripts the laws to perform miracles, in particular the Resurrection of Jesus Christ.”
What do you make of William Craig’s first statement? And can we have both “indeterminacy” and “determinacy” without conflict?
Thank you.
Don writes:On the other hand, if one thinks that it is a priori plausible that God exists and might resurrect someone who claimed to be His Son, then the historical evidence seems to point strongly toward the hypothesis that God does indeed exist and did resurrect Jesus Christ,
Something a little strange here: previously, you guys were talking about priors for theism vs naturalism, but now we’re talking about having a prior on theism + the sort of God who’d resurrect Jesus. But why think, a priori, that that sort of God exists?
If it’s just that God might do it, I think that gets us into trouble. On theism, God can do anything logically possible, but unless we’ve a reason to think God’s likely to behave in a particular way, it seems like an argument that “well, X is massively improbable unless you think that God might do X” could be applied to plenty of other things (especially if you have a “He Moves in Mysterious Ways” theodicy where God’s reasons are often opaque to us): who is to say that making that pig fly, while very unlikely on naturalism, isn’t something God might do? If we allow that appending “God might do X” onto any unlikely X makes X more likely, this proves too much. Reductio!, as they say in Harry Potter.
Something like this came up recently in Raphael Lataster’s paper on Craig’s argument for the Resurrection, which those of you with journal access might be able to read. A key quote appeared on Twitter. Craig: “What’s improbable is that Jesus rose naturally from the dead. But the hypothesis that God raised Jesus from the dead is not all that improbable, I think.” Latester: “Likewise, nobody claims that Jack grew his impossibly large beanstalk from regular beans; he used magic beans.” Latester’s objection is slightly different: according to Craig’s response to Latester, Latester thinks that Craig’s use of the Resurrection as evidence for the existence of God is question-begging. Craig says that he intends his earlier arguments (Kalam, Fine Tuning, Moral) to be arguments for generic theism, and once this is established, the Resurrection narrows this to Christian theism. Even if we grant the first 3 arguments (including the terrible Moral one), it still seems like there’s a gap here. As someone on Twitter says:”How often does God resurrect people that he [Craig] thinks it’s not improbable?” There are plenty of apparently good miracles that God might do that he doesn’t, so, knowing just what we do after those first 3 arguments, what’s special about resurrecting 1st century Jewish apocalyptic proophets? Craig’s response is to talk about the “religio-historical context”, but I’m not sure what he means by that.
Don,
” I do indeed believe that God re-scripts the laws to perform miracles”
Why believe that? On what grounds? Where’s the data? Isn’t true that the only reason you have any idea about a specific God is that you read it in a book, where told it by someone else that read it in a book. And the book(s)?
What’s a Liar’s Bible? It’s a book in which a liar makes claims about his own divinity or other powers, and is indistinguishable from a book written by a genuine divine being. Circular reasoning, begging the question, affirming the consequent.
How do you know there aren’t two gods? Or a billion? Or gods of your god? Or any gods at all? How do you know the universe wasn’t a lab accident? Sure looks like one.
What’s your theory about the super-physics that God uses the manufacture this universe such that the super-physics creates our physics?
How do you know that the process of universe creation isn’t guaranteed to always produce universes with just the constants we find? Or at least universes with a small range of variation. If God rolls a divine six sided dice he will only ever create universes that vary by 1 in 6. What then of the infinite possible universes?
How can you make any claims to knowledge in the complete absence of data about extra-universe matters? What makes you think that anything we learn from inside this universe tells us anything about the formation of universes?
To get to miracles form zero data seems a big leap of faith. And I guess that’s what it is. So why talk Bayes or theories or reason at all?
Ron Murphy,
As one wary of dredging up old ghosts without new information, I would encourage you to read through Don’s previous comments as he’s responded to at least a good few of the many questions you brought up. Granted you (and I) might not find the answers satisfactory, but otherwise he’d probably be left answering the same questions over and over unless you wanted to focus on something specific.
Josh,
I apologize for the delay in responding. Just after your May 7, 2015 at 8:29 am response came in, our family needed to drive the 320 kilometers (200 miles) from Edmonton to Calgary to attend the convocation at the University of Calgary where our son John received his M.D. degree (proud father here, but most of the credit beyond John goes to my wife Cathy, though of course ultimately I believe all the credit goes to God), and we did not get back until midnight (finding that most of the 8 cm of snow we received the day before had melted).
I agree with A, that I am “Saying the truth one should perceive comes down to how you set those priors.” I am not sure about B, that I am “Saying that’s the primary cultural difference in what the two sides (nontheists/theists) are doing.” I am saying that whatever the cultural differences are, they seem to have the result of effectively making the priors different between the two sides, if one casts the discussion into the Bayesian terms that to me seems best for analyzing how to get posterior probabilities from initial beliefs and evidence. But I can see that the cultural differences that lead to these different priors need not initially be explicit differences in beliefs about the prior probabilities of theism versus atheism; they might be differences of degrees of skepticism about certain broader classes of hypotheses that then have the result of making the priors for the more specific hypotheses of theism and atheism different.
Dear TY,
Let me make Response 700 by noting that in one sense I agree with William Craig that “Quantum indeterminacy is proof positive that modern science is not based on determinism,” since modern science continued to be science even for those who believed that quantum theory is indeterminate. However, after the many-worlds interpretation of quantum theory was developed by Hugh Everett in 1957, it was realized that quantum theory could be deterministic, and this does seem to have become the majority view among those in my fields of quantum gravity and quantum cosmology.
This deterministic version of quantum theory does have the counter-intuitive consequence of predicting that there are many different actual futures at each quantum choice, so it is the entire set of futures (and their measures, which can be interpreted as is they were probabilities, even though they do not reflect any true randomness) that is deterministically predicted, and not any single individual future.
As to whether one can “have both `indeterminacy’ and `determinacy’ without conflict,” I think so at least in the following sense: Suppose quantum theory actually is indeterminate (though I personally believe otherwise). Then at the level of that theory (which I would regard as incomplete), things are not determined, but God could determine (and would, in my view) what is left undetermined by the incomplete theory. So at one level (that of the incomplete indeterministic quantum theory) there would be indeterminacy, but at a higher level (that of a complete description of world) there would be determinism.