EXECUTIVE SUMMARY: Be careful with the probability calculus. It's =
-really- easy to get burned, and to say things that are very foolish =
without even realizing it.
THIS IS IMPORTANT:
The mere fact that some occurence is unlikely, even extraordinarily =
unlikely (1 in 10^200, say), does not in itself give any evidence =
whatever of supernatural intervention. (E.g., the atoms of my keyboard =
being in the precise configuration they turned out to be at time t =
probably has a likelihood of WAY under 1 in 10^200, but that surely =
doesn't mean we should conclude that God intervened to place the atoms =
precisely where they were at that moment.)
What makes a given improbability interesting is its being dramatically =
more likely on the hypothesis of theism (or Christianity, or YEC =
Fundamentalist Christianity, or....) versus a competing theory (e.g, =
NATURALISTIC evolutionary theory). (This is why my keyboard isn't a =
virtual demonstration of the existence of God -- why think this =
particular unlikely atomic configuration is more likely under theism =
than under naturalism [leaving aside cosmological arguments, for the =
moment]?)
Comparative probabilities -- that's step 1. But remember two other =
major caveats:
(1) A given theory can be EXTREMELY LIKELY wrt one set of data, and very =
UNLIKELY all things considered (e.g., strongly confirmed by data set 1; =
then proven false by data set 2).
(2) A major factor often not considered (because of its difficulty or =
even inscrutability, or more often just because of people's ignorance of =
the probability calculus) is a theory's A PRIORI probability.
E.g., suppose I proposed a creation theory in which Satan created all =
things to look EXACTLY the way they look to us now. Now this is much =
better confirmed by the current evidence than any ordinary scientific, =
philosophical, or religious theory of origins, since it predicts exactly =
what we find, nothing more, nothing less. Amazing! Not. The a priori =
probability of this theory is intuitively EXTREMELY low, it being a =
purely ad hoc, complex, and utterly bizarre and counterintuitive theory. =
But if all we looked at was a fit with the evidence -- hey, it's got =
it!
So to assess the overall probability of a theory, you'd need to assess =
it wrt ALL evidence and take into account its a priori probability. =
With partial evidence, we need to do the best we can (humbly assess it =
wrt the available evidence) -- but there's still the tricky a priori =
probability to take into account. (I think atheists and agnostics often =
fall short on this, protesting too much our natural theistic intuitions =
and not giving theism the high a priori probability it deserves [though =
they can counter by pointing out how such intuitions can run amok with =
superstition, fraudlent faith healers, etc. etc. etc.].)
This is why many careful thinkers prefer to speak only in terms of =
confirmation and disconfirmation by the evidence, without speaking in =
terms of overall likelihood or unlikelihood: it allows them to skip over =
the very tricky a priori and all-things-considered probability issues.
--John
----------
From: Glenn Morton[SMTP:GRMorton@gnn.com]
Sent: Sunday, September 15, 1996 11:11 am
To: evolution@Calvin.edu
Subject: miracles during protein manufacture
The chance argument is used by Christians to say that evolution is so=20
improbable as to require an Intelligent Designer. Gish uses this:
"Precisely correct! But that is the problem, not the
solution. Of course each of the four players is certain to
receive 13 cards. But which 13 cards? The order of the cards in
the deck has been arranged by a random process--the shuffling of
the cards. It is impossible to predict, before the cards are
dealt, which 13 cards a particular player will receive. He is
aboslutely certain to receive 13 cards of some kind, but the
chances of his receiving any particular set of 13 cars is 1 in 4
x 10^21. If the cards could be dealt once every second, it would
require about 10,000 times 20 billion years before a player would
have an even probability of recieving a pre-ordained set of 13
cards. That would require a long card game indeed! Now suppose
that this had to happen one million times to the same player!
"If a monkey was supplied with a typewriter and paper and
was allowed to tap the keys of the typewriter as many times as
there are letters in this sentence, it is certain that that many
letters would appear on the page. There would only be one chance
in 26^176, however, that the monkey would have typed the preceding
sentence without any spelling errors. The number 26^176 is so
huge it exceeds the number of particles in the trillions times
trillions times trillinon times trillions times trillions times
trillions times trillions of universes! An evolutionary origin
of life, however, would be enourmously less likely than that.=20
People like Kitcher live in a dream world where evolution is God-
-nothing is impossible with evolution. The incredible
improbability, or actually the impossibility, of evolution by
strictly naturalistic mechanistic processes has been documented
by numerous creationsits, anti-evolutionists, neutral
investigators, and frustrated evolutionists."~Duane T. Gish,
Creation Scientists Answer their Critics, (El Cajon: Institute
for Creation Research, 1993), p. 222-223
Lets apply this reasoning to the folding of proteins. If it requires =
God to=20
perform unlikely events in our world, then it would follow that God is=20
involved in the folding of each and every protein. Nature performs this =
task=20
in a couple of seconds.
"It has been estimated that a supercomputer applying plausible rules for
protein folding would need 10^127 years to find the final folded form =
for even=20
a very short sequence consisting of just 100 amino acids. In fact, in =
1993
Aviezri S. Fraenkel of the University of Pennsylvania showed that the
mathematical formulation of the protein-folding problem is =
computationally
'hard' in the same way that the traveling-salesman problem is hard. How =
does
nature do it?"~John L. Casti, "Confronting Science's Logical Limits,"
Scientific American, Oct. 1996, pp. 102-105, p. 103
While God is most assuredly the designer and sustainer of our universe, =
is it=20
really necessary for Him personally to fold each protein in each and =
every=20
cell on the planet? Is this an example of a miracle? How do we tell?
glenn
Foundation,Fall and Flood
http://members.gnn.com/GRMorton/dmd.htm