I. Definitions and Presuppositions
Before I start critiquing the propositions, I want to set forth
very brief and minimal descriptions of the way I define the
important terms used in this paper - this will set forth in plain
sight most of the core presuppositions upon which the points I make
in this paper depends.
First, I take methodological naturalism to be the practice of
adhering to the kind of methodology a metaphysical naturalist
devoted to fulfilling the aims of science would adhere to.
Methodological supernaturalism, correspondingly, is the practice of
adhering to the kind of methodology a metaphysical supernaturalist
devoted to fulfilling the aims of science would adhere to. Astute
readers will note that these two categories are not altogether
mutually exclusive - a point which will resurface later on in the
paper.
Second, I take science to be an enterprise that endeavors (1) to
uncover as many phenomena present in the universe as possible, and
(2) to provide for those phenomena explanations that correspond
with what really exists "out there." It should be clear from this
that this paper presupposes a scientific realist interpretation of
the goals of science, which I will not attempt to argue for here. I
will leave it to others to determine how other interpretations of
the objectives of science might affect the arguments I make (my
suspicion, however, is that they will not have a significant
effect).
Third, I take the supernatural to designate the standard things
like gods, fairies, ghosts, necromancy, divination, and so forth,
all of which are united by the fact that they exploit materials or
processes the basis of which extends or derives from beyond the
physical universe. It is worth noting that the word "supernatural"
is not, contra Strahler, analytically the same thing as "beyond the
domain of science" - to equate the two, one must show that anything
that exploits or results from transcendent materials or processes
is beyond the domain of science, which is not a simple matter of
definition.
II. Can Methodological Naturalism Say Anything About the
Supernatural?
Proposition 1 expresses the standard view of the scientific
community that methodological naturalism renders science and the
supernatural entirely isolated from one another. Science presumably
can say nothing at all about the supernatural, whether positive or
negative. Even if supernatural forces are constantly at play around
us, methodological naturalism would presumably forbid scientists
from ever acknowledging them. In this section, I will argue that
this view is false - trivially in that methodological naturalism
can falsify supernatural hypotheses, and not so trivially in that
methodological naturalism can also confirm supernatural
hypotheses.
At this point, it would be a good idea to try to explicate the
nature of methodological naturalism a little more thoroughly. I
have claimed that methodological naturalism is the practice of
adhering to the kind of methodology a metaphysical naturalist would
employ if he wanted to fulfill the basic aims of science. Recall
also that I take the basic aims of science to be the uncovering of
phenomena in the universe, and the attempt to provide for those
phenomena explanations that correspond to the way the universe
actually is. So how would a metaphysical naturalist try to fulfill
these aims? By doing exactly what practing scientists currently do:
he would use emprical observation as a means of discovering things
about the world, and would attempt to provide plausible
naturalistic explanations for the things he observes.
Now at first glance, this may seem to entirely destroy my project -
if the methodological naturalist must attempt to provide
naturalistic explanations for the things he observes, then doesn't
that automatically bar him from even considering the possibility of
a supernaturalistic explanation, much less accepting it as the most
plausible one? I would argue that, initial appearances to the
contrary, methodological naturalism does not rule out any
explanation a priori. To see why this is, let us recall that
methodological naturalism is defined by the way a metaphysical
naturalist trying to advance science would act. I think it is
relatively clear that such a person would have to be a fallibilist
with respect to even his metaphysical beliefs; remember that he
wants to be as sure as he can that his explanations correspond to
the way the world really is. Since he does not have all possible
data, he cannot be sure that there is not some kind of evidence for
the supernatural out there, so he would not want to trap himself in
a routine that would ignore even blatant evidence for the
supernatural in favor of a less plausible naturalistic hypothesis.
The metaphysical naturalist who wishes to fulfill the aims of
science cannot rule out the possibility that his metaphysical views
may eventually be shown to be wrong - hence, he must be open to
some degree to supernatural explanations. However, this degree is
likely to be a very slight one, which is what gives methodological
naturalism its naturalistic flavor - the methodological naturalist,
in acting like a metaphysical naturalist devoted to science, will,
while being open to the slight possibility of evidence for the
supernatural, consider naturalistic hypotheses on average more
parsimonious than supernaturalistic ones, and hence will give them
more benefit of doubt. In short, his methodological commitments can
tell him to examine all possible naturalistic explanations for a
phenomenon first, and can assign higher prima facie probabilities
to such explanations on average, but the least plausible
naturalistic explanation will tend to have a lower prima facie
probability than the most plausible supernaturalistic
explanation.
Let me try to illustrate this with a few examples:
Let's imagine that instead of the scientific data we currently
have, that we have uncovered the following facts: (1) every stratum
of rock contains exactly the same fossils at every level, even in
the very lowest strata; no species is represented in the fossil
record that is not alive today; and no evidence of intermediates
between any two taxa shows up anywhere; (2) radioisotope dating
shows that every stratum of rock in the earth, and every piece of
rock in the solar system has the same age - namely, about a few
thousand years; (3) every species - even anatomically similar ones
living in the same region - possesses genetic material composed of
radically different chemicals and relying upon vastly different
coding systems. This is the kind of scenario scientific
creationists probably dream about, and rightfully so - what kind of
naturalistic explanation would explain such data as elegantly as a
supernatural creation hypothesis? A methodological naturalist faced
with such data would, I think, end up having to choose between
something along the lines of a supernatural creation hypothesis and
the naturalistic hypothesis that the atoms in the universe
configured themselves into their current form through a massive
thermodynamic fluctuation. In the face of such a dilemma, I don't
think a methodological naturalist would have any misgivings about
choosing the supernatural explanation. Add to all of this data the
sudden appearance of the glowing word "God" in the sky over every
populated area, and I think even Strahler would accept a
supernatural explanation without fearing that he is destroying
science.
This, of course, was a toungue-in-cheek example designed to show
the in principle possibility of methodological naturalism
confirming a supernatural hypothesis. In reality the universe does
not show such blatant, unambiguous signs of creation, which is why
scientists currently judge naturalistic explanations to be prima
facie more parsimonious on average. But it is not beyond the realm
of possibility that this might change - there are still some areas
left where supernaturalistic explanations may ultimately turn out
to be more plausible than naturalistic ones. I believe cosmology is
good example of such a area - currently, our best cosmological
theories seem to contain a number of ad hoc constants that are
stuck in various places to make a fit with the data. If, after many
decades of reasearch, no naturalistic explanation as to why those
unlikely constants - providing the exact conditions necessary for a
universe with life in it - are there instead of others can be
formulated, I believe the idea of supernatural creation will begin
to seem more and more plausible as time goes by. This is not to say
that I believe this is how things will end in actuality - quite the
contrary in fact - but I think I have to conceed the possibility
that they might end up that way, and methodological naturalism will
not serve as a barrier to it. The same kind of scenarios can be
drawn up for other currently troublesome areas of research, such as
origin-of-life studies.
Of course, if naturalistic methodology can lead to the confirmation
of supernaturalistic hypotheses, it can also lead to the
falsification of supernaturalistic hypotheses. In fact, this is
what has appened to a number of models offered by scientific
creationists. Far from being unfalsifiable, the hypothesis that the
earth was created 6,000 years ago by a supernatural entity has been
falsified by the discovery of so much data that points to the old
age of the earth. Likewise, the notion that a supernatural being
directly created every "kind" seperately is given the lie by
excellent transitional sequences. This is, I think, trivial, but
there seems to be a lot of confusion about it, because scientists
often assert that hypotheses like these creation models are
unfalsifiable. However, such assertions on their part are
themselves a bit confused - I think what scientists mean when they
label hypotheses like special creationism unfalsifiable, is to draw
attention to the fact that proponents of supernaturalistic
hypotheses frequently fail to admit any data that disconfirms their
hypotheses, and hence act unscientific themselves. But it is
perfectly clear that a large number of hypotheses that appeal to
the supernatural make sufficient emprical predictions to be
falsified.