## Wednesday, November 21, 2012

### e: Bayes' Theorem

I'm going to start by taking Metacrock's side here, for once. As a working numerical scientist, I feel like I have a bit of weight to throw around on this subject, too

I think Metacrock is right in that the claim "ECREE" with regards to the existence of God has little or nothing to do with Bayes' Theorem. The reason for this is actually clear when you look at the examples in this thread, cocaine use and cancer. If you give a random US citizen a cocaine test, the low incidence of cocaine use means that you'll get a lot of false positives. Cocaine use is an extraordinary claim, and you need a very accurate test (or several tests) in order to convincingly show cocaine use. If you go to a crackhouse, you'll probably be able to tell pretty reliably who is high at the moment without any drug test. Similarly, any particular cancer diagnosis is a rare and extraordinary claim, and the tests have limited power. But if one test is positive, you're in a cancer crackhouse, and more testing will be much more reliable. Bottom line: You need to know the prior odds of an outcome to know the reliability of a test.

We don't know the prior odds of the existence of God. We cannot apply Bayes' Theorem on this question, because we don't have any data about the existence of God, period. I think this is the heart of Metacrock's point, and in this he is correct.

A caveat: I think the existence of God is an extraordinary claim, and my intuition says that such claims require extra convincing evidence. I agree with ECREE with regards to the existence of God, but will not use Bayes' Theorem as support for this opinion.

Finally, there's the whole miracles issue, too. Here, we do know the prior odds of spontaneous recovery from various illnesses, or we can at least calculate a reliable estimate. Therefore, when someone prays and is healed, we can apply Bayes' Theorem and we do have a mathematical basis for ECREE in this context. Every argument for miracles (at Lourdes or elsewhere) that I've seen has failed to address this fundamental problem. Can Metacrock dig up a counterexample?
In other words, belief in God is far from extraordinary, so the basis for comparison that we need to label a claim “extraordinary” has to be taken on a case-by-case basis. We can’t just label all religious thinking “extraordinary claims.” Clearly belief in God is not extraordinary, as I demonstrate in the previous blog piece (but this hardly requires demonstration). The “extraordinary” is a problematic term in science. Thomas S. Kuhn argued that scientific paradigms turn over when there are too many anomalies to explain them all through the orthodox paradigm. The “normal” business of science, according to Kuhn, is that of absorbing anomalies into the paradigm. “Anomalies” are not necessarily extraordinary, but both concepts deal with departures from the expected. The atheists tend to think of this Saganian imperative in terms of dazzling wonderment. In other words, extraordinary claims are those that they find extremely hard to believe; big amazing claims that require big amazing proof. Examples I’ve seen the average atheist on message boards give would include things like God arranging the stars to spell out messages confirming the truth of Christianity, parting the red sea and so forth. These ideas are much more grandiose than Kuhn’s anomalies. Richard Dawkins seeks to argue that God is improbable on the basis of uniqueness. There is no other evidence for any sort of thing like God anywhere in our field of experience as a species. Thus God has to be improbable because we have nothing else to compare God to. Again we are dealing with the concept of the out of the ordinary. We are dealing with ideas of the unique, that which stands out. This is a good indication that scientific thinking seeks an orthodoxy that requires mutually accepted cultural constructs to from a basis of consensus. Of course scientific thinkers will stand staunchly upon the empirical “totally proven” aspects of their views. But what is really happening in science and in party lines that branch off of certain people’s monopolizing of science is that it’s a struggle of orthodoxy against revolutionaries, and the struggle revolves around accepted worldviews, which take on an aura of the sacred. Belief in God comes ready packaged in its own aura of the sacred. The battle between scientifically based skeptical empiricism vs. religious belief is a battle of religions in a sense. It’s a party line seeking to secure itself against heretics. Atheists do not have facts that prove their views; they merely have worldviews that collide with the worldviews of religious people.

Moreover, the dictum about extraordinary evidence is also circular reasoning. That is not necessarily true, but the application that I have seen most often is circular. The skeptic says, “this is not good evidence, it isn’t extraordinary enough.” But the believer says, “Ok here’s more.” That doesn’t apply because we know from past experience this isn’t extraordinary, its too much like the other evidence, it wasn’t extraordinary either. Therefore this evidence is not extraordinary. For example say we are arguing about miracles. The Lourdes miracles have 65 examples where the official miracle finding machine of the church says, “this is an official church miracle.” The skeptic says “only 65? That’s not extraordinary, these are just anomalies. They are just remission. Then the believer points out that there are also 4000 remarkable cases, which can’t be explained but they just missed being tagged as “official” because they lack some perfunctory piece of evidence, but there is enough evidence to say they are “remarkable.” They do say of these cases that they are “remarkable.” One would think that “extraordinary” would be the same or similar to “remarkable.” But the skeptics just say they are not extraordinary they are just like the other 65, the other 65 have been dismissed for not being enough of them therefore the 4000 should be dismissed because the original 65 aren’t extraordinary so they shouldn’t be accepted and the 4000 shouldn’t be either because they are no more amazing than the 65. All that’s really going on is the 65 are being dismissed because there aren’t enough of them, but when more are shown they are dismissed for not being amazing enough. I can’t document that exact exchange, although I have been through it many times on message boards. Lest one think this is just an anomaly of the denizens of message boards, there is an example of major scientists acting this way.

Marcello Truzzi has a proposal to replace the dictum; it makes a lot more sense.

Truzzi proposal:

In addition to recognizing and working through the issues I have raised above, we need scaled terms to deal with levels of evidence for the best of the extraordinary claims put forth by protoscientists. Scientists might well distinguish between extraordinary claims that are: suggestive, meaning interesting and worthy of attention but generally of low priority; compelling, meaning the evidence is strongly supportive and argues for assigning a higher scientific priority for greater investigation; and convincing, meaning most reasonable scientists examining the evidence would agree at least a preponderance of evidence supports the claim. Using such graded language might help us turn from our present debates, with room only for winners and losers, into dialogues between peers, all of whom should want to see science judiciously progress. We can all be winners.

The upshot of all of this is religious belief is normative for human behavior. It is not merely "normal" but "normative" meaning it sets the standard. Belief is basic to human psyche, to our understanding of the good, of meaning in life, the ultimate limits of reality, the grounding of nature and being itself, there is no way belief in God can be thought of as an extraordinary claim! We might think of it as extraordinary in the sense of being unique, like no other claim, but in that case it makes no sense to subject it to the regular canons of science as though God's presence is given in daily empirical data. Obviously the more intelligent evidential standard is that the evidence has to be fit for the claim. Fit, not dazzling, not impossible, not amazing, no beyond our ability to produce, but it has to fit the case. It has to be rational, and able to stand a prima facie burden, and it has to fit the proof attempted. The difference is that the atheist standard is Ultima facie, “all things considered” rather than “on the face of it.” The ashiest absolute proof, and that absolute proof must be furnished by just one standard, scientific empiricism. The Prima facie standard makes much more sense than does absolute proof, (1) because there cannot be absolute scientific data of questions beyond the empirical realm; (2) belief is an individual question of a personal existential nature; belief deals not merely facts about things in the universe, but about one’s place in the universe. For this reason it has to be subjective, it has to be primate, personal, by its nature it is not provable in the absolute scientific sense. There’s no use pretending that the absolute scientific umpire is the only form of knowledge. I will take this up in a latter chapter. The point here is that Prima Facie case fits the subject matter in a much more rational way. All we can ask of a world view is rational warrant anyway. World views take in too much to be demonstrated entirely from empirical data.

source on Truzzi

Marcelo Truzzi “on some unfair practices toward claims of the Paranormal.” This article was published in slightly edited form in:Edward Binkowski, editor, Oxymoron: Annual Thematic Anthology of the Arts and Sciences, Vol.2: The Fringe, New York: Oxymoron Media, Inc., 1998. It is also found on the website Skeptical Investigations: http://www.skepticalinvestigations.org/anomalistics/practices.htm visited 7/7/08

Weekend Fisher said...

I think the main problem is that ECREE / ECREP is that all it does is open up infinite regress. For example:

You say "The existence of God" is extraordinary, and requires extraordinary proof. Ok, let's say God offers up extraordinary proof: like the resurrection of Jesus. The burden of extraordinary proof has been met.

But wait, the atheist can just say they disregard the extraordinary proof, *because* it's extraordinary, so now you have to have extraordinary proof that there really was extraordinary proof.

I'd say: Jesus has an extraordinary life, and extraordinary teachings. He's all the proof I need. (Then they'll line up someone to try to take that away ...)

I think I'm gonna make this my Thanksgiving post, back at the home blog.

Happy Thanksgiving!
Anne / WF

Metacrock said...

that is an excellent point! very good Fisher.

thanksgiving is over and the Cowboys lost. but thanks for good wishes

JBsptfn said...

Ha, ha, Dallas lost (from a Denver fan near Pittsburgh who hates the Cowboys, I just had to get in some good-natured ribbing, you understand : )).

I like Fisher's post. That is why the atheists try to come up with crackpot schemes like The Jesus Seminar to discredit him.

Metacrock said...

Dallas lost what? Do we have a team in some sport? My team won over thanksgiving, the Houston Texans!

;-)