Physicist Sean Carroll indulges one of his physics colleagues in a post Guest Post: Don Page on God and Cosmology. Sean:
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. … He is also, somewhat unusually among cosmologists, an Evangelical Christian, and interested in the relationship between cosmology and religious belief.
From here on I’ll address Don on his piece, by picking up only the statements I think are really problematic. I’m basically repeating what I wrote in the comments section, with some minor mods.
So, Don you say this:
… such as my assumption that the world is the best possible …
Why would anyone make such an assumption? Based on what? Compared to what? What’s a worse world? What are the metrics? The comment by Phillip Helbig says it all:
The optimist believes that he lives in the best of all possible worlds. So does the pessimist.
Back to you Don:
I mainly think philosophical arguments might be useful for motivating someone
Like propaganda? It is clear that theists are manipulating and abusing philosophy, logic, reason, evidence, to make it best fit their beliefs.
… raise the prior probability someone might assign to theism. I do think that if one assigns theism not too low a prior probability …
You shouldn’t have a prior probability about something for which you have zero data. The prior probability isn’t 100%, isn’t 0%, isn’t 50% – it’s unknown. No data. Making a guess, or expressing a bias from personal religiosity and assigning a probability is doing a great injustice to probability.
the historical evidence for the life, teachings, death, and resurrection of Jesus
What, like hearsay of Josephus passed off as evidence? There is no historical record of the words or teachings of Jesus. The death? We can barely support his existence, by extensive hearsay, but as ‘evidence’ it’s no better than claims made about Mohammed’s revelations. By the way, how do you set the prior probability that Mohammed was telling the truth about his revelations, or the likelihood he was lying, or that he was delusional? What’s the prior probability that Jesus was a nutty preacher. Using the statistics of what we do know about how common nutty preachers were at the time the best evidence we have is he’s one of many. I’d really like to know on what basis all this is judged remotely true.
Ben Goran in the comments refers to Richard Carrier’s On the Historicity of Jesus. Good choice.
… can lead to a posterior probability for theism (and for Jesus being the Son of God) being quite high.
This really will not do. For miraculous things to happen, such as a resurrection, you need a God. You presuppose a God. Then you find stuff that’s in a book that says, look, here’s a miracle of that God – without any evidence it happened beyond hearsay, and again I remind you your hearsay is competing with that about Mohammed. Then you say, look, it’s all real, Christianity rules, OK.
But if one thinks a priori that theism is extremely improbable, then the historical evidence for the Resurrection would be discounted and not lead to a high posterior probability for theism.
Don, you are mistaken in that direction too. This is really important! There is no need to think theism is improbable. One has only to be totally open to it, and then look at the evidence. There is none. What is offered as evidence turns out to be: unevidenced hearsay, nothing that can’t be illusions and delusions, lies and propaganda – and all these have at least some actual prior probabilities because we know that these latter human frailties do actually occur.
I tend to favor a Bayesian approach in which one assigns prior probabilities
But Bayesian stuff works only when you have actual statistics to form your prior probabilities. Even if they are as flaky as much statistical evidence is (and we know how we often reach wrong conclusions about the efficacy of medicines in that arena), at least it’s actual data of a sort. But for universe creation and gods it’s no better than a pretence at mathematical credibility when there’s no data to work with.
… when the product is normalized by dividing by the sum of the products for all theories
This is crazy talk. Are probabilities based on the human capacity to imagine ideas, invent fantasies? is the correct probability determined by one’s own credibility? This is not to be treated like some meta-analysis of numerous sets of actual statistical results. It’s a meta-analysis of guesses. It’s pointless.
… since we don’t yet have _any_ plausible complete theory for the universe to calculate the conditional probability, given the theory, of any realistic observation.
So, the correct response to the question of whether there is some sort of intelligent agent creator of universes is to say: I haven’t got the foggiest clue.
From there proceed to act on what we do have. The empirical investigation of the universe and what that tells us. Our understanding of minute physics may still be open to question, but at the level of chemistry, creating medicines, building planes that don’t fall out the sky randomly – and it’s all quite mechanistic, naturalistic.
The working conclusion, then, is to live **as if** this: that what we empirically find is all there is, whether it is or not, because if we cannot detect a god of any kind knowingly then whether there is one or not makes no difference. It really is that simple.
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 …
What? We’ll come back to evidence shortly, but for now let’s just go back to an earlier point, from above:
can lead to a posterior probability for theism (and for Jesus being the Son of God) being quite high
And let’s put these together:
- the historical evidence for the Resurrection of Jesus, is most simply explained by postulating that there is a God
- can lead to a posterior probability for theism [i.e. there is a God]
So, postulating a God basically leads to a posterior probability that there is a God. And, while we’re at it, the assertion that the resurrection occurred is used to show that Jesus was resurrected [because he really was the son of God].
Doesn’t that look just a tad suspicious? Don, that looks embarrassing to me.
This is no more than affirming the consequent, invoking a circular argument. Don, you could only make an argument if you had good evidence of a God, and then good evidence of a naturalism busting resurrection. You have evidence of neither. You are presupposing there’s a God that can do stuff like resurrections, taking one of the many myths and taking that to be caused by this presupposed God, and then using that resurrection as the evidence of the divine Jesus, who is God. What? Seriously, What?
But on the matter of evidence, the pretend evidence for the resurrection is most simply explained by being the myth of one of the many myth asserting religions, and that people that believed in gods in ancient times were probably even more gullible than people today. Don, you think they may not have been so gullible. How gullible do you think Scientologists are? What are your probabilities for the existence of Thetans? How about Joseph Smith? Not convinced? Well, a hell of large number of reasonably well educated 21st century people believe that nonsense. Can you see why it’s far more reasonable to think these ancients were duped, or self-duped?
I do believe by faith…
Oh no! Don, please! Not the faith get out of jail card? Well, okay, in which case you can dismiss all you said before this point as it means nothing now in this context. All that effort doing just what William Lane Craig does, pretending to use reason and evidence and probabilities picked out of your nether regions – even though you reject some of WLC’s reasoning. And all it really took is faith. Why not faith in Mohammed? Well, you’re a Christian. Is that how you do your physics?
We simply do not know whether or not our universe had a beginning, but there are certainly models
See, you can do it correctly if you try. We simply do not know. And, for God there are no models that are based on other confirmed models of physics and cosmology. Sean’s work and your work in physics and cosmology does not come out of nowhere, but all religions do: there’s always someone that we know invented a religion, or the origins of the religion are lost entirely in time. You really should be applying this cosmological scepticism to God: we do not know and we have no models and no data. There are no measurements, no mathematic models, nothing but hearsay and the occasional claims of messianic individuals that think they are hooked up with their own god.
In summary, I think the evidence from fine tuning is ambiguous
Ambiguous? It’s down right dumb. What do we know about the extra-universe ‘physics’ of universe creation, such that it does not necessarily cause universes just like this one. What if all universe necessarily must have the physics of this one, because of some as yet unknown extra-universe feature? How do we know that all these universes are not such that only initial conditions determine whether life evolves abundantly, rarely or not at all. We don’t know that the constants that **allow** evolved life actually **necessitate** evolved life. With different initial conditions it could be that the universe evolve without ever experiencing intelligent life that goes on to wonder if the universe is fine tuned. We’d then have a ‘fine tuned’ universe tuned with no tuned products in it. What reason would we have to think such a universe is fine tuned?
There’s a big difference between:
– Speculative interpretations of limited cosmological data with multiple speculatively viable theories
– Believing ancient religious stories based on stuff that’s indistinguishable from all the other stories you too would pass off as myth
That difference is that with physics one does not tend to make assertions about behaviour any morality based on them – unless they very specifically inform our understanding of human behaviour and morality, such as evolution, psychology, neuroscience. There are no moral or behavioural prescriptions or proscriptions associated with Sean’s preference for Everett, but there are real human consequences that result from people believing stuff for which there is no evidence, in religion, and the consequences are all too often not good ones.
Look at it this way:
Problem 1: A company makes bags of 100 black balls, but manufacturing errors cause some balls to be white. We know the limits: 100 black, 100 white. We know from experience that people complain if they have more than 40 white balls. We do some tests and stuff. We play with probabilities. We use Bayes. We run controlled trials. Whatever. It’s real if uncertain data. What’s the probability of getting a bag with 100 black balls? We can start to look into it, come to some conclusions, do more measurements, more sampling, more calculations.
Problem 2: How are universes made? We don’t know. As an analogy for this, this is me telling you there’s a bag out there; possibly an infinitely large bag; and it might have some balls in it or it might not. If it has, then some might be black, or not. Some might be white, or not. The bag might contain refrigerators rather than balls, or not. Now, what are you going to tell me about the content of the bag – the probability that there are 100 black balls in the bag, that there’s God in the bag, ten gods, …? Nothing. Oh, and there might not actually be a bag out there; there might just be this universe.
Problem 1 is the sort of problem we can play with. Problem 2 is God stuff. The former is the reality we have to deal with. The latter is make believe – faith, indeed.