JASA had a special issue about probability and God about 10 years ago. No
radical Bayesians, however. Very unsatisfying. No one pointed out the need
to process *all* evidence, not just miracles, but WW II, Rwanda, Kosovo,
and each pediatric osteogenic sarcoma... There was a little discussion
about priors, as I recall.
Kathy writes
>
>First is the problem of defining God. This is a tough problem, because it
>seems to me that by definition, if you can define it, it isn't God. In
>other words, to me God is that which lies beyond definition.
This is Maimonides' definition. AJ Heschel said that religion is the
interstices between words. As *we* strive to get everything down in black
and white, it does behoove us to consider that our personal needs to
intellectualize is only one response to our world, and we may be missing
the true mass of the universe by simpy focusing that which we can label.
Having said that, I still like the Bayesian formulation.
Of course, explaining the decision analytic acceptance of a religion ("the
probability of this God is above my threshold for behaving the way that
that God demands") is hard to explain to a child you're trying to raise,
who only appreciates *is* or *is not*, but not *may be*.
Harold
At 6/22/99 , Max Henrion wrote:
>
>[From UAIlist moderator: This message was sent on June 10, and
>accidently got lost in my mailbox while I was traveling - I apologize
>to Max, and to the list, for my screwup. For future reference, unless
>you think a message needs my attention, send it directly to
>[EMAIL PROTECTED] If you send it to
>"[EMAIL PROTECTED]", and I screw up again, it might be
>delayed. Again, my apologies to Max and the list]
>
>
>I beg to differ with Rolf Haenni when he writes:
> > Let me illustrate this by considering the question "Does God exists?".
> > There are two possibilities G and �G (G = "God exists", �G =
> > "God does not
> > exist"). Following the arguments of David Poole, it would be
> > necessary to
> > assign a prior probability, that is to say
> > P(G) = P(�G) = 0.5,
> > which is completely absurd (even to speak about "probability that God
> > exist" is absurd).
>
>Those with the temerity to speak about the probability that God exists are
>in distinguished company. Blaise Pascal, often claimed as the father of
>probability, was much concerned with God's probability. "Pascal's wager", as
>you may recall, is about the decision of whether to live life in the manner
>which God ordains. If you do so, and it turns out God doesn't exist, you may
>have only wasted your life. But, if you don't, and it turns out that he
>does, you experience eternal damnation (according to Pascal's Catholic God).
>So, however small the probability that God exists, you should behave as if
>He does, and so avoid the risk of an infinitely negative outcome. (Predating
>von Neuman and Morgenstern by three centuries, Pascal saw no need to
>transform utilities onto a bounded scale.)
>
>This wager was no idle thought experiment for Pascal. At the age of 31, he
>abandoned mathematics, physics, as well as gambling and high-living, and
>retired to a monastery. Fortunately for us, the Reverend Bayes had no such
>qualms about the godliness of mathematics.
>
>One may quibble with Pascal's argument: Nowadays, a Bayesian might demand a
>clarity test for the "existence of God." And what about the possible
>existence of the Goddess Anica, who provides eternal bliss to all _except_
>those who abide by Catholic teachings?
>
>Be that as it may, there remain some serious points for us:
> 1. Not everyone thinks it absurd (or even blasphemous) to talk about the
>probability that God exists - and, by extension, the probability of other
>more mundane facts or events.
> 2. Making decisions and taking action in the World implies a commitment to
>degrees of belief, even about facts or events about which we feel very
>ignorant.
> 3. Probabilistic reasoning can often be a useful basis for action, even
>without assigning numbers to the probabilities.
>
>
>Cheers
>Max
>
>___________________________________________
>Max Henrion, Director of the Decision Lab
>Ask Jeeves, Inc
>59 N. Santa Cruz Avenue, Suite Q,
>Los Gatos, CA 95030
>408-354-1841 x27, fax 408-354-9562
>NEW EMAIL: [EMAIL PROTECTED]
>www.ask.com
>
>
>
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
> > Rolf Haenni
> > Sent: Monday, June 07, 1999 8:38 AM
> > To: [EMAIL PROTECTED]
> > Subject: Re: Bayesian Networks and Belief Functions
> >
> >
> > Dear UAI Community,
> >
> > thanks to Ursula, Jonathan, and Wang Pei for their help to clarify the
> > problem of representing total ignorance.
> >
> > Let me add the following answer to David Poole's question:
> >
> > DAVID POOLE wrote:
> > >For those people who would like to distinguish ignorance for
> > the outcome
> > >of a binary variables and probability 0.5, I would like to
> > know how many
> > >different meanings are there to "I don't know" (for a binary random
> > >variables)?
> >
> > There are two different meanings of saying "I don't know" to
> > the outcome of
> > a (binary) variable Q:
> > 1) I DON'T KNOW the outcome of Q, but I KNOW (from my experience on
> > earlier or similar events or processes) a prior probability P(Q).
> > 2) I DON'T KNOW the outcome of Q, and I have no experience allowing
> > me to assign any prior probability.
> > Total ignorance corresponds to the 2nd case.
> >
> > Let me illustrate this by considering the question "Does God exists?".
> > There are two possibilities G and �G (G = "God exists", �G =
> > "God does not
> > exist"). Following the arguments of David Poole, it would be
> > necessary to
> > assign a prior probability, that is to say
> > P(G) = P(�G) = 0.5,
> > which is completely absurd (even to speak about "probability that God
> > exist" is absurd). In contrast, I think it makes perfectly
> > sense to say
> > that
> > Bel(G) = 0, Pl(G) = 1,
> > Bel(�G) = 0, Pl(�G) = 1, and
> > Bel(G or �G) = Pl(G or �G) = 1,
> > which corresponds the agnostical point of view of a person
> > who thinks that
> > nothing can be known about God (= total ignorance).
> >
> > A similiar situation is the example given by Jonathan Weiss: at the
> > beginning, when nothing is know about the deck of cards and
> > about the color
> > of the first card dealt, I think it does make sense to assign
> > probabilities
> > P(red), P(green), etc... In contrast, it makes perfectly sense to say
> > Bel(red) = 0, Pl(red) = 1
> > Bel(green) = 0, Pl(green) = 1
> > ...etc,
> > Bel(red OR green OR blue OR yellow OR "something else") = 1.
> > Note that from the point of view of probabilistic
> > argumentation systems,
> > Bel(Q)=0 means that there are no arguments in favor of Q,
> > while Pl(Q)=1
> > means that there are no arguments against Q. In my eyes, this reflect
> > perfectly to nature of total ignorance.
> >
> > Finally, let me add what Lao Tse said: "Knowing Ignorance is
> > Strength".
> >
> >
> > Best wishes,
> >
> >
> > Rolf Haenni
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > **************************************************************
> > **********
> > *
> > *
> > * Dr. Rolf Haenni __/ __/ __/ __/
> > _______/ *
> > * Institute of Informatics (IIUF) __/ __/ __/ __/
> > __/ *
> > * University of Fribourg, Switzerland __/ __/ __/ __/
> > _____/ *
> > * Phone: ++41 26 300 83 31 __/ __/ __/ __/ __/
> > *
> > * Email: [EMAIL PROTECTED] __/ __/ ______/ __/
> > *
> > *
> > *
> > **************************************************************
> > **********
> > * World Wide Web: http://www2-iiuf.unifr.ch/tcs/rolf.haenni
> > *
> > **************************************************************
> > **********
> >
> >
> >
