The Measure of All Things?

	What does it mean to call oneself a physicalist?  For the use of
this paper, I'm defining physicalism in the following way: "The belief
that those objects, and only those objects, exists which are can be
explained in terms of (or reduced to) the primitives of modern physics."
Most every strict physicalist will agree with this statement with some
argument over what it means to "reduce to" and "explain in terms of".
There is, however, a fatal flaw in this formulation of physicalism.
Physics cannot help philosophy to select a primitive ontology because it
does not itself have a consistent set of primitives.
	While this may seem a radical claim, I think it follows
immediately form a complete understanding of the nature and methods of
modern physics together with a thorough analysis of the definition.  Let
us begin by first examining in detail what is said by the definition
provided.  

What is a primitive?
	Any formal system has at least four of classes of objects:
primitives, defined terms, axioms, and theorems.  While the last three are
easily understood, the notion of a primitve is unusual to those
unaccustomed to formal thought.  The relation of axiom to theorem is
reflected in that of primitive to defined term.  Primitives are those
terms accepted without a formal definition.  Every formal system has
primitives.  It cannot be that all terms are well-defined (that is, are
not circularly defined, but are defined in terms of other terms).  In
philosophy, the discipline of ontology deals with what there is.  We can
also think of ontology as the quest for a set of primitves in terms of
which to explain the rest of the world.  A general ontology is a set of
objects which are thought to populate the world.  A primitive ontology is
the set of objects to which the general ontology can be reduced.  This
reduction often takes the form of constitution; for example, a table may
be constituted out of wood, which is constituted of organic molecules,
which are constituted of hydrogen, oxygen, nitrogen, carbon (and some
other atoms), which are constituted of electrons, protons, and neutrons,
which are constituted out of quarks (and some other particles).  If we
believe tables to exist, they form a part of out general ontology.  If we
can offer no explanation of what constitutes a quark (that is, what a
quark is made of) then quarks are part of our primitive ontology.

A term may very well be primitive in one system, but not in another.  In
high-school calculus, the notion of a natural (counting) number is most
often primitive.  However, in set theory (for example) the natural numbers
are very well defined terms developed at a high level of sophistication.
Another analogy is the spectrum of colors.  When we speak of pigments,
red, blue, and yellow are primitive.  However, when we deal with optics,
cyan, magenta, and yellow are used.  (this analogy lacks the arbitrarity
of more abstract systems).  
It is also the case that different formulations (or models) of the same
system may use different primitives.  Quine spoke of this when (in Word
and Object?) he proposed a tribe that spoke not of rabbits as primitive
but rather of unseparated rabbit parts.  However, he did not follow
through with the notion in the context of formal systems.  A simpler
analogy is perhaps kinship, where we may think of Sara as Ellen's
daughter, and Ellen as Nancy's, or without loss of information, we can
translate to speak of Sara's mother Ellen, and grandmother Nancy.  For a
formal example, look at geometry.  In a Euclid's system (as per Elements)
he took points to be primitive.  In the Egyptian system, distances were
primitive.  They do not define different geometries; they define different
models of the same system in terms of different primitives.  

What is a model?
	A model of a formal system is consists of the primitives,
definitions in terms of the primitives, and rules describing the relation
of terms (both primitive and defined) to each other).  It's important to
note that primitives need not be simply "noun-like" objects, but also that
"verb-like" relations and operations can be primitive.  For example, in
set theory, the relation "is an element of" or "belongs to" is primitive.
In grade-school, addition and multiplication are primitive, and
subtraction and division are defined there from.  Different models of the
same system may look quite different from the outside.  For example, for
many centuries, the fields of algebra and geometry grew separately.  They
developed to a high degree of sophistication, each very different from the
other.  However, Descartes finally realized that they were, in fact, the
same thing, and his synthesis of analytic geometry permanently changed the
face of mathematics. 
What are some models of the universe?
	In every day practice, we use many different models of the world
around us.  The most common one is the "common sense" system, which takes
a great deal of primitives.  Tables, chairs, people, emotions, owning,
wanting, creating are all primitive.  We are all quite familiar with this
system, and comfortable with its use, so I'll not dwell on it.  Similar,
but slightly more refined is a Platonic formulation, where there are a
large number of noun-like primitives, and only one primitive relation "is
the essential form of".  All relations between objects are described in
terms of the relations of their essential forms.  Cartesian dualism is
another familiar model.  In this, there are two rough classes of
primitives, physical and mental.  Most popular among modern philosophers,
however, are the physicialist  models.  While these differ in many
respects, at their core, they assert that the primitive ontology of the
universe is the same as that used in physics  .
How has physics' ontology developed, and how does this relate to the
development of physicalism?
	Physics' ontology has undergone any number of dramatic changes,
and the last century has provided some of the most sweeping change.  In
the interest of brevity, I'll provide only a brief sketch of the history
of the field.  More information on the history of physics is easily
obtainable.
	Physics as we know it began with Greek natural philosophy.  In
those early days, there were many competing primitive ontologies.  The
archetype-elemental ones (all of nature is made of some subset of {Fire,
Water, Air, Earth} in some combination) had perhaps the most accepted
following, and continued to influence modern science well into the
Renaissance .  Democritus made a wild hypothesis concerning the
fundamental indivisability of some objects, and called them "atoms".
After the fall of Greece to Rome, the development of chemistry (the
investigation of the nature of matter) was postponed.  It wasn't until the
mid 15th century that science once again become vital, this time shocked
into movement by the hermetic alchemists.  While many people believe that
alchemy was a mere proto-chemistry, and that her aim was the
transformation of gold to lead.  This however is a grossly oversimplified
view, which in many ways is completely wrong.  Alchemy, at her most
fundamental, is the attempt to transmogrify the soul from its base
physical prison into a pure and exalted form.  As espousing this sort of
view could very well get one labeled as a heretic (and, in fact, led to
the entirety of Southern France being placed under interdict during the
4th Crusade), the work was encoded in archetypical-elemental codes.  Lead
is the symbol of the planet Jupiter, and, as such, is used to represent
the material/carnal world.  Gold is the symbol of the sun and represents
purity, divinity, and ascension.  Perhaps the best analogy for the
alchemists work is "The aim of magic, the method of science".  It is hard
for many people to realize, but alchemy laid the groundwork of the
scientific method.  The alchemists' work with the basic metals and salts,
which they carefully manipulated in order to unlock their secrets, did not
escape the attention of Isaac Newton, the first modern physicist, himself
a celebrated alchemist .  Newton went on to develop the first consistent
set of physical primitives, and was the first to formalize physics.  He
proposed a universe consisting of small, solid masses in constant motion.
His success with this set of primitives led Dalton to, in 1803, propose a
similar primitive ontology for chemistry.  Dalton's atomic theory was to
lay the groundwork for all the work to follow.  Maxwell, in 1873, proposed
the addition of another set of primitives to science, magnetic and
electric forces.  A number of important discoveries at the end of the 19th
century led to the startling conclusion that the "atom" was not
indivisible.  By the 1920's phsyics had once again come to a stable set of
primitives.  Bohr had developed a system explaining the way in which atoms
worked in the inside (this is the "orbital" theory we still teach in
beginning chemistry classes), and it seemed that physical chemistry was
nearly done.  Then came the tempest.  A whole horde of particles was found
to constitute the "indivisible" particles inside an atom.  With some
refinement, it is at this level that physical chemistry now resides.  Her
primitives are the quarks, leptons, baryons, and mesons.  
So, what's wrong with using this primitive ontology?
	There are a number of problems.  Most obvious, is the fact that
there is little reason to believe that we've finally "gotten it right".
In all likelihood, new primitives will come to replace these, as these
"elementary" particles have come to replace sub-atomics, and atoms and
archetype-elements.  Most physicialists, however, will not stake so much
on contemporary physics, however, and reformulate their view as such "Only
those objects are rpimitve which are spoken of by a "perfect" physics."
Here there is a more subtle flaw, one which requires us to again look
formally at the notion of a primitive.  I spoke before of different models
of the same system.  This is just as real a possibility in physics as it
is in mathematics.  There are a number of other formulations of quantum
theory which DO NOT take quarks, leptons, baryons, or mesons as primitive.
They may seem radically unintuitive, at first, even in comparison to
"standard" quantum formulations, but that is only because they do not
descend from the alchemical/atomic model.  
One such is the "multiple worlds" theory of David Deutch.  He proposes
that rather than there being microscopically indetermined particles in a
macroscopically determined world, there are an infinite number of worlds,
each determined, synchronously determined.  In this view, every time an
electron decays, a universe is created for each photon (up or down) that
it emits.  Before Schroedinger looks in his box, to see if the cat is
alive or dead, he exists simultaneously in two different universes -- the
"cat dead" universe and the "cat alive" universe.  
Many of the other, more radical, primitive ontologies come out of research
into a theory of quantum gravitation.  Right now, physics has two largely
separate systems for explaining the world around us.  The quantum model
deals with very powerful interactions over very very small distances.  The
relativistic model speaks about a fairly weak force (gravity) over large
distances.  So far, there has been little consensus on how to reconcile
them.  
What does this mean for ontology?
	Physics is not debating which primitive ontology is the "right"
one, they are debating which is the "best".  There can be only two
criteria for the evaluation of competing primitive ontologies.  First, is
the primitive ontology useful?  That is, does the set of primitives give
us the descriptive power to talk about all the things we feel are
important to have in a general ontology, including "inner objects" such as
beliefs and emotions?  The second criterion is known as Occam's razor, and
stipulates that a smaller primitive ontology (that is, one with fewer
primitives) is better.  If two different models of the same system are
equal in the eyes of these two criteria, then they are both equally
"correct".  It is quite likely that as physics continues to evolve, it
will take for itself a number of different primitive ontologies, each
usefule for different applications.  It is just this that has made the
difference between modern chemistry and modern physics.  Chemistry as a
rule uses sub-atomics as primitive, and occasionally ventures into quarks
and mesons.  Physics most often takes the elementary particles (q,l,b,m)
as primitive, but is actively looking for alternatives.  Many branches of
physics use other far "spookier" things -- two-dimensional
"super-strings", eleven dimensional god-particles and, completely
non-physical wave-form equations -- as primitive.  Each of these models is
useful and correct in its own right, and they all describe fundamentally
the same system (or,at least, they attempt to).  Physics does not have as
its concern the establishment of one set of primitives.  Such an endeavor
would be fruitless and misguided.  Physics establishes a set of
primitives, and then attempts to describe the world in terms of them.  It
is not that the Bohr model is "incorrect", it is that it models the system
on a far more macroscopic level.  The current quantum model is just as
unusable on the large scale as Bohr's is on the very small.  For
philosophy to attempt to envision a "perfect" physics is ridiculous.
Physics is not and never can be perfect.  It can perfectly model the world
around us, but there is NO REASON AT ALL that it could not perfectly model
the world in many different ways, each stranger and more radical than the
other.  Every model of the world requires its own set of primitives.  We
have seen that one system of primitives is supplanted by another, more
useable one.  We have also seen multile concurrent primitive ontologies,
all correct, used to describe different facets of the world.  It has been
the case over the senturies that whenever a new primitive ontology came
along that introduced a powerful new way of talking about the world, a new
science sprang up around it.  The notion of basing philosophy on the
primitive ontology of a perfect science is, at its core, utterly invalid.
A perfect science is an infinite science, one in which EVERY viable set a
primitives can be used to explain the world in an infinite set of
interrelated, interdependent models.  Just as geometry and algebra each
give us a powerful way to talk about topological relations, yet are
completely different on ontology and form, so to is it that science
presents us with multiple models of the same system, each with it own
primitive ontology.  There is no primitive ontology of a perfect science,
and in just such a way it falls to every physicalist to decide whether
they really believe there could be one perfect primitive ontology of the
universe.  


footnotes:
  The belief that there is only one kind of stuff, and it is "non-spooky",
I'll call naturalism.  I reserve physicalism for a specific kind of
naturalism defined in the next sentence.  
  Some flavors of physicalism assert that the correct primitive ontology
of the universe is the same used by a completely correct physics.  I'll
deal with this variant as well.
  Actually, it may be better to use "physical chemistry" as physics has a
great spectrum well outside the interest of establishing a universal
primitive ontology.
  The four bodily humours, for example, are completely reducible to the
four archetypical elements.
  See, for example, his work on light.