Tuesday, October 05, 2010

Reply to Loftus on miracles and prior probabilities

I argue that when it comes to miraculous claims yesterday’s evidence no longer can hold water for me, for in order to see yesterday’s evidence as evidence for me, I must already believe the Christian framework (i.e., the Bayesian priors) that allows me to see yesterday’s evidence as evidence for Christianity.

Are these your prior probabilities, or are these priors everyone else is supposed to have? If the former, that may be true. But if that's all it is, then you are going to have trouble getting irrationality charges off the ground. I am not in the business of making irrationality charges. I don't think that the evidence for the Resurrection is sufficient by itself to rationally compel belief. I just think there is a lot that is hard to explain about the founding of Christianity that makes more sense if the supernatural is admitted than if the supernatural is not admitted. I realize people like McDowell say it's irrational to be skeptical, given the evidence, but it's beyond my powers to make such a case. In other words, I am engaged in what Steve Davis calls soft apologetics, although I also maintain that the Resurrection evidence is a cumulative case role-player in a case for theism. (You haven't read my two papers on miracles, have you?)

The problem is that no amount of philosophical thinking alone will produce the conclusion that any event actually took place in the past, much less a miraculous resurrection. So on the on hand, in order to establish the Christian faith believers must use historical evidence at every juncture. But on the other hand, in order to see that evidence as evidence we need to have good reasons to do so. Where do those reasons come from? Not from any “background knowledge” or “priors” of theirs. They cannot use their so-called “background knowledge” or their “priors” to help determine whether the evidence shows Jesus arose from the dead until they can first show that he did. Christians must independently establish that the resurrection took place in history before such a belief can be placed into their bag of "priors."  


If we can't use our priors, whose priors do we use? My claim is you have lots of people out there, from people who think Christianity very antecedently likely, to people who think the central events of Christianity might or might not have happened and are looking at the evidence to see if it did, to people who think Christianity is absurd and wouldn't believe if Jesus were to sit down across from them at lunch. The subjectivist theory of prior probabilities says that rather than find "correct" priors and argue from those, we simply have to use our own priors and adjust our confidence as we look at the evidence. How do we look at the evidence? We ask if the evidence, such as we have it, is more likely to be the way it is if the Christian story is true than if the Christian story is false. Now suppose I successfully show that the evidence that comes down to us from the first century is more likely to be the way it is if the Christian story were true than if the Christian story were false. Well, then we Christians would have grounds for having more probabilistic confidence in our Christianity, people sitting on the fence would become Christians, but those who have strongly skeptical priors would remain skeptics, but they might scratch their heads a little bit of how this could possibly have happened the way it did. AS C. S. Lewis said.

Early in 1926 the hardest boiled of all the atheists I ever knew sat in my room on the other side of the fire and remarked that the evidence for the historicity of the Gospels was really surprisingly good. “Rum thing,” he went on. “All that stuff of Frazer’s about the Dying God. Rum thing. It almost looks as if it really happened once. “… Was there no escape?”
by C. S. Lewis Surprised by Joy (New York: Harcourt Brace Jovanovich, 1942), pp. 223-224

That hard-boiled atheist never converted, but he nonetheless accepted the fact that the founding of Christianity was "rum" from the standpoint of his atheism. And maybe that's all we can expect from the argument.

But we can look at the facts and see if they are more likely given Christianity than given not-Christianity. That is a comparison we can make regardless of our priors. We have no logical method that I know of for determining what our priors ought to be, and certainly no argument proving that the prior for miracles ought to be vanishingly low.

This problem is fatal for anyone who wishes to believe Jesus bodily arose from the dead in history. We can even grant the existence of Yahweh or a creator god and the possibility of miracles and it changes nothing. For what needs to be shown is that Yahweh did such a miracle here in this particular case and the historical tools we have available to assess whether he did are inadequate for the task. 

The reason why our historical tools are in some sense inadequate is that we have to live with a situation where prior probabilities differ widely. So historical evidence will probably not be sufficient to allow us to pin irrationality charges on our opponents. But guess what. YOU are the one making the irrationality charges, which means YOU have to prove them. I believe that we can determine, historically, whether the evidence is more likely to exist given a supernatural theory of the founding of Christianity, or whether it is more likely to exist as it does given a naturalistic theory of the founding of Christianity.

I like Bob Price who says that even if God raised Jesus from the dead there is no way we can know that he did.

Depends on your understanding of knowledge. If what we mean is that the evidence is sufficient to persuade all reasonable persons, then no. If what we mean is that we can have good reason to suppose that the historical evidence confirms the supernaturalist hypothesis, that it is more likely to exist as it does given supernaturalism than given naturalism, then yes, I think we can have a justified, true, belief that Jesus rose from the dead if, indeed, Jesus did in fact rise from the dead.

THAT is the case and only practically brain dead people refuse to acknowledge this.

There you go again, with this irrationality charges, for which you need proof, and for which you have provided none. You are claiming that no reasonable person can believe in the miraculous origin of Christianity. You have to demonstrate either that the historical evidence, such as we have it, is more likely given naturalism than supernaturalism, or show that everyone ought to have very low priors for the Christian miracles. Good luck with that.

24 comments:

Anonymous said...

I admire you for sticking to this, Victor, but you've gotta known that no amount of reasonable argument, evidence to the contrary, or whatnot will be sufficient to get John to back off on the "OTF". How many times do you have to hammer away at the flaws in his argument, and point out the gaping holes, before you get this?

It's like that story about Bruce Nevins of Perrier being asked to identify his company's water in a taste test. He couldn't. Did he admit the next day that, huh, I guess Perrier doesn't taste superior after all - our products are fatally flawed? Of course not. He couldn't. There was far too much invested, and his role was to defend Perrier no matter what. You could demonstrate to any unbiased, reasonable observer that Loftus' OTF is a sham, and it won't matter. Only if he thinks it will be better PR for his scribblings or his popularity or whatnot will he cave. Being wrong alone isn't reason enough for him. The OTF is his Perrier.

I'm not arguing you shouldn't engage Loftus' "arguments", by the way. I just hope you're not actually trying to win a concession out of John himself.

Blue Devil Knight said...

It's not like priors are some magical set of probabilities immune to revision.

The crux of the matter is that if you already have to be sympathetic to Christianity to buy the arguments for Christianity, then the Christian worldview is in trouble!

Unfortunately, that's what you end up with if you fetishize priors too much, or treat them as some special class of beliefs that are not subject to the same standards as other beliefs.

You risk ending up with a mutually reinforcing set of nutball propositions that "cohere" really well with one another. Evidence, not priors, deserves a special place in our justificatory practices, as it is evidence which tethers our beliefs to reality and adds friction to the speculative philosophical systems that otherwise tend to spin out of control.

Priors aren't fixed, and they should be based on evidence and reason just as much as one's "posteriors." Otherwise what you might call a 'cumulative case' others might call a self-consistent mutual reinforcing system of madness.

Victor Reppert said...

What I am doing is saying that priors are going to differ. That's one of my main points. So I am just going to give reasons who the posterior side favors Christianity, and leave it up for grabs as to whether it does so to a sufficient degree or not. I don't believe that is to fetishize priors, is it? What I'm claiming is that there is no normative way of establishing that everyone priors should be a certain way, and therefore it's going to be hard to underwrite irrationality charges in this debate.

Don't expect Loftus to be convinced that his test doesn't work. What I would like to convince him of is that polite dialogue about the merits of his pet intellectual idea is the way for it to achieve the influence it deserves. With the AFR, the process of responding to critics like my doctoral advisor Hugh Chandler, as well as critics like Jim Lippard, Keith Parsons, Theodore Drange, Richard Carrier, and BDK, as a few examples, has improved the development of the argument, and helped me to see what critical views have to be responded to. Calling the other side names in lieu of argumentation is counterproductive.

Anonymous said...

The crux of the matter is that if you already have to be sympathetic to Christianity to buy the arguments for Christianity, then the Christian worldview is in trouble!

Define "sympathetic to Christianity". Merely having priors which, upon investigating the evidence, would lead one to regard Christianity as most likely true, quite probably, more probable than not, etc? I should hope not. Otherwise any set of priors which would yield that result upon examining the evidence is a case of priors which are "sympathetic to Christianity" from the outset.

Nor is it clear to me that priors should not be some "special class of beliefs", or that it even makes sense to talk about "evidence" in the absence of priors. Take away all beliefs and merely evaluate the evidence and... you can't evaluate the evidence. You can't even tell what is and isn't evidence. Sure, perhaps someone can change their priors for this or that reason, but pretending that we can evacuate ourselves of all priors and beliefs then proceed to evaluate the evidence is a joke. Indeed, it seems downright delusional to me.

Notice, by the way, something Loftus said here: We can even grant the existence of Yahweh or a creator god and the possibility of miracles and it changes nothing. For what needs to be shown is that Yahweh did such a miracle here in this particular case and the historical tools we have available to assess whether he did are inadequate for the task.

Think about what Loftus just said: Granting the existence of Yahweh, of a creator God, as well as the possibility for this God to intervene directly in the world and cause miracles changes nothing re: evaluating the case for the Resurrection.

To compare: Let's say I have a letter in my hand, bearing a signature. I'm trying to figure out if this letter was really written by the person whose signature it bears, whose existence I am either utterly uncertain of, or who I doubt as of day 1. Day 2 rolls around and I find out one detail: The person whose signature is on this letter? They exist. Qualify it to "at some point, they existed" if you wish.

Should I regard their authoring the letter in my hand as more likely now?

Anonymous said...

Don't expect Loftus to be convinced that his test doesn't work. What I would like to convince him of is that polite dialogue about the merits of his pet intellectual idea is the way for it to achieve the influence it deserves.

Right. Since when does Loftus care about getting what he deserves? He has said explicitly that he wants to persuade, period, whatever it takes. What if the merits of his idea are lousy and he knows it, but he thinks he'll get the results he wants if he calls names and puts on the show he does?

What do you think Bruce Nevins would say that if he was polite and totally honest in his evaluation of Perrier, then Perrier would get the reputation and the sales it deserves? He may say, "Well thanks, Victor. That's the best argument for lying and persuasive marketing I've ever heard in my life!"

Blue Devil Knight said...

Victor: I think you sometimes err on the side of dumping too much work onto priors rather than evidence and arguments. OTOH, you could just say, "I don't care about people who don't accept x, y, and z, I'm not arguing with them as there isn't enough common ground."

Anon: in theory it is hard to distinguish theory and evidence, but in practice it is really easy.

Those who do not actively and vigorously seek to constrain and modify their beliefs using evidence (and are not mathematicians or logicians) often end up with highly coherent, consistent systematic worldviews that are worth a bucket of spit (I'm thinking of various philosophical systems such as behaviorism, conspiracy theories, young-earth creationism).

I agree that John was wrong in that claim you quoted.

By 'sympathetic' I basically meant 'already believes it, or gives it more credence than the evidence would justify. That's the dangerous territory Victor sometimes flirts with (that you will only believe if you are already sympathetic is basically a concern about begging the question).

In human beliefs, I do not believe there are fixed, unrevisable priors. I take the Quinean turn pretty seriously.

Anonymous said...

Those who do not actively and vigorously seek to constrain and modify their beliefs using evidence (and are not mathematicians or logicians) often end up with highly coherent, consistent systematic worldviews that are worth a bucket of spit (I'm thinking of various philosophical systems such as behaviorism, conspiracy theories, young-earth creationism).

Man, that doesn't seem right. How do I know people who end up at those conclusions "do not actively and vigorously seek to constrain and modify their beliefs using evidence"? What if they do that and are just bad at it? Because I can guarantee that when you ask those guys, they'll often insist they're going where the evidence leads them. And I don't feel comfortable with the amount of psychoanalyzing present in a possible response of "Well yeah, they would say that wouldn't they"?

Something seems very wrong there, even if it was just an offhand comment. Circular? Maybe there's a limit to what reason and evidence can securely establish. Maybe it's looser than we'd all like.

By 'sympathetic' I basically meant 'already believes it, or gives it more credence than the evidence would justify. That's the dangerous territory Victor sometimes flirts with (that you will only believe if you are already sympathetic is basically a concern about begging the question).

I don't see that, or that Victor even flirts with such a belief. To give it more credence than the evidence would justify would be a different argument than over whether we can evaluate evidence sans priors or beliefs. (And I'll note that this doesn't require that priors are 'fixed and unrevisable', just that there's always some priors, and always must be to even touch the evidence, or even identify it.)

Isfs said...

Is there a reason arguments from predictive prophecy don't seem to see the light of day any more?

I wonder whether the priors used in evaluating those cases are more or less problematic than those for evaluating the resurrection.

John W. Loftus said...

Vic, if your "priors" are truly "priors" then they need to be there "prior."

So here you are wondering whether Christian theism is true. You were probably raised to believe in this Christian culture but now as the adult you have become you want to examine the case for yourself.

So when doing so what are your "priors" at that point? That is, what do you know and when? When do you place which "priors" into your bag of "priors"?

Name them in order to the best of your ability. And tell me how you arrived at them without using any subsequent ones.

John W. Loftus said...

I had said: We can even grant the existence of Yahweh or a creator god and the possibility of miracles and it changes nothing. For what needs to be shown is that Yahweh did such a miracle here in this particular case and the historical tools we have available to assess whether he did are inadequate for the task.

This is both obvious and non-controversial. For the very people in charge of the writing and maintenance of the OT faith, the Jews, believed in Yahweh and miracles and yet did not believe in Jesus--to this day.

Yes there are pockets of Jews who do believe, but statistically not many of them at all.

John W. Loftus said...

Now given my last comment, I defy anyone to provide for us a clear and unequivocal non-self-fulfilling prophetic text in the OT that singles Jesus out as the only person who could fulfill it using the historical grammatical method of interpretation.

Tim Callahan in Bible Prophecy looks into this with tests and so forth.

It cannot be done.

Steven Carr said...

'Early in 1926 the hardest boiled of all the atheists I ever knew sat in my room on the other side of the fire and remarked that the evidence for the historicity of the Gospels was really surprisingly good'

In other words, nobody ever met Judas,Lazarus, Thomas,Joseph of Arimathea, or had even heard of a town called Arimathea.

And Christians like Paul could write that the Roman authorities held no terror for the innocent, even though the Gospels claim the Romans stripped, beat, whipped, flogged,mocked, tortured and crucified Jesus.

And which 'hard-boiled atheist' does not simply laugh at claims of Muhammad ascending into the sky on a horse, or Jesus flying into the sky on his way to Heaven?

Blue Devil Knight said...

Anon: some people have confirmation bias, and think they are being evidence driven, but are just looking for data that supports what they already believe.

If you aren't willing to judge them, then we differ. I'm happy to pass judgment on various conspiracy theoriests, young-earth creationists, and philosophical behaviorists.

Note I'm not saying Victor is guilty of begging the question. I'm just saying that sometimes when he talks about priors, it has a kind of magical quality, like that is enough to settle it, that they are unmoved movers. I doubt he believes this.

Another worry is this focus on subjective probabilities can lead to a "mutually reinforcing" system that is bologny. It could easily become circular, and people should be wary of putting too much faith into it. For instance, imagine the following two-belief tinker-toy example:

I believe in God because of the evidence for the resurrection.

I believe in the resurrection because of the evidence that a God exists.

Those two beliefs can be part of a "mutually reinforcing" cumulative case for God, but you see the danger right?

The question is how can you differentiate a mutually reinforcing system of bullshit, from something that is reasonable? My claim (outside of logic and math, which it isn't clear this applies to) is evidence, and there are better and worse ways to incorporate evidence into one's belief system (e.g., runaway confirmation bias versus serious attempts to destroy one's ideas).

My worry is that constantly deferring to 'priors' can be a way to avoid discussion of the reasons and evidence for particular facets of one's web of beliefs. Priors aren't a final court of appeals. They can change. Mine have changed. If we take it to its extreme, why argue at all, why use reason, why look at evidence, we can just consult our priors?

Obviously nobody is at this extreme. And obviously Victor doesn't shy away from arguments about individual facets of his belief system. He tends to face them head-on, and is good about building them into an overall worldview.

Also, I'm not saying that the theism/atheism question can be completely decided by evidence and reason. It cannot. I actually agree with Victor for the most part. There are resonable people on both sides that see the exact same evidence. This is Feldman's point, and I largely agree. That's why I tend to not like calling religious folks brainwashed, deluded, stupid, ignorant, etc..

John W. Loftus said...

Hey, how long could you have a reasonable discussion with a Scientologist, Vic, before you simply calls 'em as you sees them? You've been taking pot shots at me for about five years now. Five years! You have not read my magnum opus claiming you've heard it all before. You haven't. You are indeed brainwashed. I do not live up to what anyone else might think when it comes to you. YOU should know better. You're supposed to be a philosopher who can see connections to arguments that others cannot see. But you simply refuse to do so. This happens time after time after time after, well, that's what I show anyway, time after time after, well, you get my point.

That's what I think. I provide the arguments and then I tell you what I've concluded from dealing with you for over five years.

You don't like it? Then you have options. Either grow a brain or leave me alone from having to deal with things a first year logic student should see clearly.

Yes, I like you, there's no doubt about that. This is not personal. I have some really close people in my life who cannot think too. But I don't expect them to. You I do.

Cheers.

natamllc said...

I believe these verses can hit the target, the bullseye, center pointe on at least two levels; one, C.S. Lewis' friends view and two, of the three entries for the phrase, "the just shall live by faith", found in Scripture, this one shows "the why" some just don't "live by faith" that miracles are a part of our Salvation:

Hab 2:1 I will take my stand at my watchpost and station myself on the tower, and look out to see what he will say to me, and what I will answer concerning my complaint.
Hab 2:2 And the LORD answered me: "Write the vision; make it plain on tablets, so he may run who reads it.
Hab 2:3 For still the vision awaits its appointed time; it hastens to the end--it will not lie. If it seems slow, wait for it; it will surely come; it will not delay.
Hab 2:4 "Behold, his soul is puffed up; it is not upright within him, but the righteous shall live by his faith.
Hab 2:5 "Moreover, wine is a traitor, an arrogant man who is never at rest. His greed is as wide as Sheol; like death he has never enough. He gathers for himself all nations and collects as his own all peoples."


Behold, someone has to be behind a soul being puffed up, then! :)

Most likely, they won't believe who it is inflating their soul, if we told them!

Why?

That too takes believing in miracles! :)

Bilbo said...

Sort of off-topic, but wouldn't a good test of whether a particular point of view passes the OTF is whether outsiders do in fact come to adopt that view?

If so, then I imagine every current religion, including atheism, passes the OTF.

Victor Reppert said...

The whole discussion of priors is a way of "bracketing" the whole left-hand side of Bayes' theorem so that we can focus our attention on the right hand side. If the evidence surrounding the Resurrection is such that it is more likely to have existed given the Resurrection than given no resurrection, then that is an interesting claim in and of itself even if people can walk away skeptics because the evidence just isn't "extraordinary" enough. How extraordinary is extraordinary enough? Some people think that something surviving out of the ancient could never be sufficient, because of the lack of scientific tools in the extant culture for checking things out. I don't agree, but I just want to see if the evidence really confirms Christianity or not. I think that it does, and I think that an atheist should be able to see that even if they remain atheists because of their priors.

Of course our priors have to be sensitive to the evidence. It's just that it doesn't have to be the case, with respect to an argument on this issue, that all skeptics ought to be convinced if it's a good argument.

I don't consider the culture I grew up in to be an overwhelmingly Christian culture. Most of the people I spent the most time around in high school were not Christians. Most of my academic life has been spent in secular academic institutions. Anyone who thinks I got the beliefs I currently have through intellectual inertia caused by a Christian environment knows nothing about me at all.

My epistemology says that you are entitled to start with the priors you have, but in order to maximize the chance of knowing the truth, you have to actively seek and consider fresh evidence. And if the a posteriori evidence is strong enough, it will eventually swamp the priors and lead everyone to the truth, even without forcing ourselves to step outside of our own skin with the Outsider Test. The Outsider Test is a worthwhile thought experiment, but there really isn't a way to get truly outside, and to pretend that you can get yourself above the fray through "skepticism" strikes me as illusory.

So I am just suggesting that, for the time being, we leave everybody's priors be and just ask whether the evidence is more like what you should expect if Christianity is true than if Christianity is not true.

It is really unfortunate that John insists on hurling insults in place of presenting arguments. When you do have an interesting idea, and the OTF is interesting to be sure, you need to carry on some open dialogue with critics in order to get the most mileage out of your idea. Apparently on a site called Skepticmoney, some pretty militant atheists were disappointed in John's debate tactics. But that's a story for another post.

Victor Reppert said...

One way of looking at this is this whole concern of yours about priors, BDK, is to put it in the context of a discussion of irrationality charges. My view is that irrationality charges require extraordinary evidence, and a legitimate pluralism about priors is going to make those charges very difficult to prove. Now, does that mean that I am entitled to just sit on my priors and refuse to consider contrary evidence? Not at all. Looking at my own epistemic life, I can't do that. But my view makes it hard to be judgmental about the epistemic lives of others. And that, I think, is a good thing.

John W. Loftus said...

So Vic, where did you get your "priors"?

Where?

And how do you come to believe the resurrection of Jesus without them, or with ONLY the "priors" that Yahweh probably exists and that miracles are not impossible?

Where?...and How?

The fact is that God cannot exist if Yahweh didn't. Yahweh did not exist. He is much too tribal of a god, created the world in conflict with the sea God Yam (or Rahab), married to Asherah, accepted child sacrifice, commanded genocide, forbid religious freedom, chose Israel like the others gods did to other nations.

The only thing left is that miracles are not impossible. But that conclusion doesn't lead you to think there were witches at Salem, or the miracles at Lourdes took place, or that snake handlers can miraculously handle snakes.

You got nothing.

Victor Reppert said...

Well, the case for Yahweh looks reasonably good if you look at it this way.

Out of the polytheistic morass that was the ancient world, how do we get that revolution in thought that led to monotheism. How did they do it? Why in Israel, and NOT in Greece, NOT in Rome, NOT in Egypt, NOT in Babylon. The concept of Marduk did not develop into the idea of the supreme God of the Universe, nor did Baal, nor Asherah, nor Zeus, nor Apollo, or Quetzacoatl, nor Horus. Even Ikhnaton's monotheistic experiment in Egypt was erased under King Tut.

If you can explain how monotheism survived amongst the Jews, when it was consistently a hair's breadth away from extermination time after time after time, then explaining how the Cardinals made it to the Super Bowl in 2009 should be a piece of cake.

Anonymous said...

Prof R,

Imagine what a loss to the Christian world (& too your own career since you wrote a book about it) it would have been if C.S. Lewis reacted to Anscombe's critique of the early weaknesses in his early version of the Argument from Reason the way Loftus reacts to critics of his OTF?

Victor Reppert said...

Lewis would have had a lot of trouble arguing that Anscombe was a brainwashed atheist.

John W. Loftus said...

Here's the problem Vic. You claim to objectively want to know if your faith is true but you continually do the opposite. You do not trust me to tell you how to do this. You will not read the books I recommend. You only listen to others.

Nonetheless here's another one I recommend. I wrote a blurb for it but I'm sure you would pay no heed. Pay heed to the others.

And ignore that crap about this book dealing a blow to inerrancy. It deals a blow to conservatism in all it's forms.

Victor Reppert said...

Are you engaged in honest inquiry as to the truth of your own atheism? Is there anything fair and balanced at Debunking Christianity? I happen to have been studying Hallquist's book on the Resurrection. Have you read McGrew's essay on the Resurrection in the Natural Theology volume? Have you read mine? I see no evidence whatsoever that you have read my book either, and it's been out since 2003. You just trust that Beversluis has answered it. You expect me to appoint you as my teacher when you fail to observe simple rules about conducting debate properly?