> Hi George, thank you for your comments!
> george murphy wrote:
> > firstname.lastname@example.org wrote:
> > > Jonathan Wells' "Icons of Evolution" has been criticized repeatedly and
> > > recommended a few times on this list. J.A. Coyne's rabid criticism,
> > > "Creationism by stealth", Nature 410 (12 April 2001), 745-746, has also
> > > been mentioned.
> > >
> > > In Reasons to Believe's Facts for Faith issue 5 (1/2001), pp. 60-61,
> > > Fazale R. Rana provides a very much more sympathetic discussion of
> > > "Icons".
> > There is no single set of observations &/or experiments which _prove_
> > biological evolution in general or a particular theory of biological
> > evolution. That's the case with any scientific theory & is especially so
> > with one like evolution in which a great deal of the relevant phenomena were
> > in the past. In addition, any number of theories can be developed to
> > explain a given observation. _Ceteris paribus_, the best theory is the one
> > which explains the widest range of observations with the fewest number of
> > _ad hoc_ &/or untestable hypotheses. A number of the following criticismss
> > are effective only to the extent that the experiments or observations are
> > supposed to be "proofs" of evolution rather than evidence which is
> > supportive of it. In particular ...
> I agree with your basic concept of a scientific theory and it's (lack
> of) general provability. I don't expect textbooks to give "proofs" for
> evolution, and I consider neither Wells' nor my objections to be
> "proofs" against evolution. However, we should expect textbooks
> presenting evidence for evolution to select the strongest pieces of
> evidence available. If all of what they provide is either irrelevant, or
> ambiguous as evidence, they aren't doing a good job. The crucial point
> is that evolution usually is presented as an undisputable fact, and not
> just as the theory "which explains the widest range of observations with
> the fewest number of _ad hoc_ &/or untestable hypotheses".
Yes, evolution should be presented not as unqualified "fact" but as theory. I
would add that it is the best scientific theory - in the sense I stated above - of
the development & history of life we presently have.
All observational evidence for a theory is "ambiguous" to some extent: It
is very hard to think
of a single observation or single class of observations which can be explained by
one and _only_ one theory. It may be, e.g., that the homology of vertebrate limbs
can be explained by theories that don't involve common descent. That does not,
however, mean that such homology is not supportive of evolution _when taken
together with other observations and experiments_. A theory which is a viable
competitor of "standard" evolution must be in accord not only with homology but
with all the other evidence which is supportive of evolution.
E.g., textbooks often cite the excess precession of perihelion of
Mercury's orbit as evidence for Einstein's theory of gravitation. It would be
wrong to say that perihelion precession itself "proves" general relativity: There
are a number of alternative theories which do that as well. But when the totality
of observations (light defelection, gravitational wave damping &c) are considered,
it's pretty clear that Einstein's theory does the best job of explaining them all
with the fewest arbitrary assumptions.
> In fact, the
> principal untestable hypothesis assumed is philosophical naturalism. The
> power of the evidences for evolution depends very much on the previous
> assumption of theism or atheism.
This is true only in the sense that scientists assume that God is not an
element of scientific explanation - i.e., what has been called in a rather loose
way "methodological naturalism." Most scientists who are Christians operate in
this way whether they have thought out their assumptions carefully or not. (No
competent scientist, when confronted with a puzzling result of an experiemnt, will
be content to explain it by saying "God did it.") Moreover, one can present good
_theological_ arguments to validate such "methodological naturalism."
It is quite another matter - and I think simply untrue - to say that this
is equivalent to an assumption of "atheism" in the ordinary sense of the word.
George L. Murphy
"The Science-Theology Dialogue"
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