>"By MN we know that gravity keeps the planets in their orbits."
Really? Methodological naturalism (MN) is conspicuously absent
from Newton's _Principia_, and I couldn't find any mention of it in
the physics textbooks on my office shelves. MN is front and center,
however, in nearly every textbook I own on evolutionary theory.
Hypotheses of intelligent design (ID) are excluded categorically as
"unscientific." Not false. ID is "unscientific."
Allan also wrote:
>"By MN we know that the Sun condensed gravitationally billions of years
>ago from nebulous material and eventually began to burn by nuclear fusion."
This is more interesting as a counterexample to Phil's thesis.
But consider the following.
Suppose a scientist doubted the standard theory of stellar evolution.
Perhaps he decides that, for instance, the so-called "collapse problem"
(Larson 1978) is unlikely to be solved by any natural mechanism.
So he proposes that, on the grounds of the available evidence, stars
are intelligently-designed, or created, objects.
What do you suppose his chances are for publication at any of the
major astrophysics or astronomy journals?
I'd say his chances are nil. Not because of the evidence, however.
In a curious fashion all empirical considerations will prove to
be irrelevant. Rather, he will run afoul of MN. In the case
of theories of *origins*, MN is all-important, and all-governing.
As Stephen Brush (1990) observes:
Explanation is...a major function of theories. As Lyttleton
(1968, p. 5) points out, scientists "cannot really quite relax"
until they are assured that "the laws of science are sufficiently
comprehensive to allow the solar system to happen" -- we
demand that the origin of the solar system be explained
without invoking any supernatural events.
Brush's demand -- a clear statement of MN -- is philosophical. The
demand is made before consideration of any evidence, and thus
cannot be overturned by the evidence. In this sense MN is pernicious
to any science seeking the truth without fetters.
Paul Nelson
Brush, Stephen. 1990. Theories of the origin of the solar system
1956-1985. _Reviews of Modern Physics_ 62:43-112.
Larson, R.B. 1978. Collapse Dynamics and Collapse Models.
In _The Origin of the Solar System_, ed. S.F. Dermott
(New York: John Wiley & Sons), pp. 237-254.