Wednesday, July 29, 2009

Bayes' Theorem Producing Dividends

I've been having a lot of fun over at str discussing issues related to the initial implausibility of the resurrection and how that affects the believability with Jason Engwer. He indicated at Triablogue that he was over there, so I went to have a look and noticed him insulting a skeptic named Joe in a way that was very typical of him. For instance, just look at the top of the thread here and you'll see him going after Joe personally. "Joe doesn't know much about history. Notice the deep irrationality of Joe's position" etc, etc.

So I jumped in to point out to Joe that he needn't take things too hard. Jason's insults are very typical of him. Part of his standard repertoire. I gave some examples. Then I started discussing the issues with Jason.

Jason responded in typical fashion. Amy from str then entered and had to tell Jason to tone down the obnoxious rhetoric. That's fine if he wants to do that at Triablogue, but that's not how they operate at str. She deleted some portions of his post and my portions that had to do with my discussion of him personally. Apparently this was not his first warning and he was warned that he could be blocked if this continues.

In the meantime Jason had posted his own thread at Triablogue. Insulted by Jon Curry. As if I had insulted him just now. In fact Jason was busy digging into the archives to find something that could be taken out of context in a manner to suggest bad insults on my part. There's no need for me to look to years ago documentation to find Jason engaging in personal attacks. Just look to the current thread he's participating in.

But this was an unusual opportunity for me. Here's Jason ready to debate, but he's restricted from personal insults and from rudely directing his statements toward the audience as opposed to me. Pretty nice. Why not pursue this further? So I did.

Several interesting things have emerged. First of all, as Jason knows, my brother Bill and I think it is useful to use Bayes' Theorem to evaluate the believability of the resurrection. It's easy to say things like "there's nothing implausible about God raising Jesus from the dead" and "the fact that ancient people were sometimes gullible and superstitious doesn't matter too much." But when you actually quantify these matters it exposes how rational these statements really are. Bill and I find that Christians typically don't want to get too detailed and quantify these matters, and we think we know why. Bayes' Theorem has a way of laying bare assumptions in a way that exposes the irrationality of Christian thinking.

The way to squirm out of the problem is to attempt to undermine Bayesian inference. Steve Hays at Triablogue tried his hand at this here. There are 6 billion people in the world. The existence of someone like Bill Curry would thus be extraordinarily implausible. So we shouldn't believe he exists. Jason commented in the same thread and presumably thinks Steve is raising good objections.

But now over at str Jason is quoting Craig and Moreland with regards to how it is reasonable to believe the winning lottery numbers reported in the paper despite the fact that any particular number is initially extraordinarily improbable. Craig and Moreland rely entirely on Bayesian inference for their evaluation, and I couldn't agree with them more.

Jason would then subsequently argue that my view has problems because we often believe things that lack precedent. Over and over again I'd respond by saying I agree, and I entirely agree with Craig and Moreland's explanations. I don't think Jason quite understood what it was Craig and Moreland were saying. I think he thought they were agreeing with him and against me, but in fact the opposite is true. Jason has entirely undermined his and Steve's objection to Bayesian inference by quoting Craig and Moreland.

Several other interesting things have emerged in the course of this discussion which I think once again shows the strength of Bayes' Theorem. It lays bare the assumptions. Jason's assumptions are being exposed. In my view it exposes the irrationality of his views. Here are some of his beliefs:

1-Jason says that if you were to consider a resurrection claim and part of your background knowledge was that the person was regarded as some sort of messiah and a miracle worker, you would not initially consider the resurrection claim to be unlikely. So, just as a hypothetical, assume Hadhrat Mirza Ghulam Ahmad was believed to be the Messiah and a miracle worker by some Muslims. Assume he was claimed to be risen from the dead a few decades back. Before even considering the evidence we should start with the presumption that this claim is not unlikely. My view is the opposite. It's extremely unlikely. If you agree with Jason I guess you'd be quick to believe that Jesus was likewise raised.

2-Jason has used the example of earthquakes frequently. He says if you'd never heard of one, never seen one, and had no reason to expect one and if you were to stop and consider the likelihood that the ground is about to move you wouldn't initially consider it to be unlikely. I say that you would and if suddenly the ground started moving you'd be shocked. If you didn't experience it yourself but simply heard the report of it you might not believe it, and that would be rational. Jason says no.

3-Though a single eyewitness wouldn't be good enough for a murder case, Jason doesn't understand why it wouldn't be good enough for a miracle claim, like perhaps a resurrection. To me the answer is self evident.

These evaluations are in their very nature subjective (another point Jason had misunderstood, thinking that for some reason this was problematic). So it's not really that I think it needs to be argued. Jason clearly has a much different threshold than me regarding what he finds to be initially believable. I think it's rational to dismiss the claims of Hadhrat Mirza Ghulam Ahmad without really looking into them. Look into them if you think that's interesting, but it's so exceptionally unlikely that it's reasonable to just ignore it. Or what of a miraculous claim? Should I believe it if it's reported by someone and that's all the information I have? To me there's no question. Absolutely not. Jason doesn't feel the same way. This explains why I find him to be a very credulous person and perhaps why he would regard me as too skeptical.


Jim Turner said...

Wow, that's quite the thread! I read most of the STR threads and participate in some of them, but this one escaped me. Very interesting!

Anonymous said...

I admire your extraordinary patience in dealing with Jason.

Frankly, my encounters with Triabloguers have left me feeling dirty, insulted and frustrated. I've begun to understand the rhetorical tricks that they use ("that's an assertion, not an argument"), but as someone with a science background, it can be a surreal experience to exchange views with people who think that you win arguments by manipulating words. It's also an odd thing to interact with people who take something as absolute truth, simply because it was written down by a human at some distant place and time.

Anyway, again, I'm impressed by your willingness to play the game.

-"Joe" from STR

Ben said...

I've heard it said (by apologetic folks like Mike Licona) that our background knowledge doesn't apply to miracle claims and perhaps he is correct. But the logical failure there is concluding we are still in a position to evaluate the claims.