ABSTRACT:  Science cannot prove that some past event was "supernatural;"
however, it can in principle establish that no known natural mechanisms
could account for that event.  In that limited sense, science can address
the supernatural.

-------------------------------

INTRO:

"Science and supernatural explanations" is a recurrent topic in this group
and in the entire origins debate.  It may be an exercise in hubris on my
part, but I'd like to compose something which is reasonably brief, clear,
and agreeable to as many people as possible.  I'd value feedback.

-----------------------------

When science investigates a puzzling event (either an "origins" event long
ago, or a more recent event such as an unexpected healing), science cannot
determine whether or not that event was supernatural.  What _can_ science
do?  It can try to determine, to the best of its abilities,
  --what the conditions were before the event,
  --what the conditions were after the event, and
  --what effect known natural mechanisms could have had during the event.

(Note:  I use the word "event," but it could also refer to a series of
events spread over time, such as macroevolution.)

As scientists study the initial conditions, final conditions, and
known natural mechanisms, they could reach three possible conclusions:

1) Sound empirical models predict that known natural mechanisms can
    account for the event. (*1*)  (Let's call these "natural events.")

2) We do not have sound (or sufficiently thorough) empirical models, but
    we believe that known natural mechanisms can account for the event,
    and future improvements in empirical knowledge, elegant models, and
    computing power will eventually allow us to prove this.
    (For this article, let's call these "non-empirical events.")

3) No known natural mechanisms could account for this event.
    There are empirically sound reasons for ruling out all known
    natural mechanisms.
    (For this article, let's call these "non-mechanistic events.")

 There are two special categories which also deserve mention.  I will
 deal with them separately at the end.

 SC1) Rare "natural events" whose timing and location have special
     significance (especially religious significance) to a person or
     group of people can be called "coincidental events."

 SC2) Some objects and events indicate intelligent activity.  (E.g.
     stone tools found with hominid fossils.)  The terms "natural"
     and "non-mechanistic" become problematic, so we will call
     these "intelligently designed events" and deal with them
     separately.

(Please don't get hung up on the labels.  I'm open to suggestions.)

--------------

For any given event, there may be some disagreements in the scientific
community as to whether it is natural, non-empirical, or non-mechanistic;
however, it is possible for a great majority of scientists to agree.  Most
would agree that the formation of the solar system falls into the first
category, "natural."  Most would agree that galactic formation,
earthquakes, and zygotic development fall into the second category,
"non-empirical."  A majority of scientists believe that abiogenesis and
macroevolution fall into the second category, but a noticeable minority
believe they belong in the third, "non-mechanistic."  Most agree that the
Big Bang is in the third category.

What do scientists do with non-mechanistic events?  Individual scientists
could reach (at least) five different conclusions:

A) A supernatural event occurred.
B) Super-human technology brought about the event.
C) An unknown natural mechanism is responsible for the event.
D) A very unlikely (natural) event occurred.
E) A very unlikely (natural) event occurred, but there are many
    different causally disconnected universes.

Science _qua_ science cannot distinguish between these possibilities.
Historical, philosophical, and religious arguments are the decisive
factors in each scientist's conclusion.

Note, however, that science _qua_ science DOES play a vital role in
debating whether an event is "non-empirical" or "non-mechanistic."
Philosophical and religious arguments can also properly play some role in
this debate.  This is the realm where scientific data, scientific
intuitions, and philosophical/religious expectations meet in the same
arena.  For example, strongly materialistic scientists will work hard to
push all events into the "natural" and "non-empirical" categories.  This
effort might lead them to uncover new natural mechanisms sooner than
scientists who don't share their materialistic philosophy.  Alternatively,
scientists with strong religious or philosophical reasons for believing
that certain events are supernatural can marshal scientific arguments to
show that those events are "non-mechanistic" rather than merely
"non-empirical."  This effort might lead them to uncover flaws in proposed
naturalistic scenarios sooner than scientists who don't share their
religious beliefs.  (*2*)

Ultimately, the development of new empirical models plays a decisive role
in determining whether a "non-empirical" event is "natural" (if empirical
models predict the event) or "non-mechanistic" (if empirical models rule
out known natural mechanisms).  In the absence of such empirical models,
philosophical and religious arguments can play an important role in
persuasion, and to some extent, in formulating testable hypotheses.
Moreover, events which are deemed "natural" or "non-mechanistic" today
could change their status with the discovery of new natural mechanisms or
better empirical models.

-------------------------

Sometimes, "natural events" occur at a time and place and in such a way as
to have special significance (especially religious significance) to a
person or group of people; the argument can therefore be made that these
events have some non-mechanistic (e.g. supernatural) component.  Science
_qua_ science cannot resolve this argument; the most it can do is attempt
to determine the relative probability (infrequency) of the event, possibly
taking into account known "initial conditions."  Additional historical,
philosophical, and religious arguments are needed to consider whether the
event was "purely natural," or had some non-mechanistic component.  (e.g.
Was the event's timing and location predicted beforehand?  How soundly
does the event fit within an established theological framework?)

Intelligently designed objects/events are an interesting special case.
For example, a paleontologist might determine that the breakage pattern on
the edge a particular stone could not have happened via "natural
mechanisms" (at least, not with any significant probability).  If hominid
bones are found in the same area, however, the paleontologist might
reasonably conclude that the stone was crafted as a tool.  The intelligent
activity of hominids becomes a special kind of "natural mechanism."  A
similar argument is made in the search for extraterrestrial intelligence.
If a sufficiently complex repeating radio signal is discovered, the case
can be made that no natural mechanism could produce it except for the
"natural mechanism" of intelligent activity.

In the debate over biological origins, many people have pointed to the
analogous features between biological life and intelligently designed
objects or processes, thereby arguing that biological life was
intelligently design and perhaps, to some extent, assembled
"non-mechanistically."  This is an example of a philosophical argument
used to persuade and, to some extent, as a starting point for marshalling
scientific arguments and to formulate testable hypotheses.  (The extent to
which the argument is _convincing_ is, obviously, a point of debate.)

--------------

One final point should be made.  People can disagree about whether an
event is natural, non-empirical, or non-mechanistic.  People can also
disagree over whether or not a particular event ACTUALLY HAPPENED.  Let us
use one particularly contentious issue.  If everyone agreed that Jesus'
resurrection actually happened, then (almost) everyone would agree that
the event was non-mechanistic.  (Science _qua_ science cannot determine
whether or not the disputed non-mechanistic event actually happened;
historical and philosophical arguments must be used in that decision.)
Since the event itself is widely questioned, the debate must often shift
to other events which are generally agreed upon (e.g. the written records
and the subsequent behavior of Jesus' followers); scientific intuition, as
well as historical and philosophical arguments, are then brought forward
to debate whether these agreed-upon events are non-mechanistic, or merely
non-empirical.

-------------------------

(*1*) It is worth mentioning again that non-deistic theism asserts that
"natural events" are just as much dependent upon God's activity as
"non-mechanistic" events.

(*2*) Both of these biases could be pushed to the extreme, to the
detriment of science.  One could imagine a scientific community so
obsessed with finding naturalistic explanations for non-empirical and
non-mechanistic events that it wastes vast resources on unproductive
pursuits which yield no secondary benefits.  One could also imagine a
scientific community so complacent about supernatural explanations (or for
that matter, super-human or many-worlds explanations) that it makes
virtually no effort to search for new natural mechanisms for puzzling
events.  Fortunately, the present-day scientific community does not seem
to fit either extreme.
--------------------------------------------------------------------------------
   In theory, there is no difference between     |            Loren Haarsma
     theory and practice, but in practice        |    lhaarsma@opal.tufts.edu
     there is a great deal of difference.        |