Notes on "Do electrons 'really' exist?"
                 ______________________________________

                                 Paul Merriam

                             pmerriam@cruzio.com

                         (received: August 11, 1997)

	Azam Mashhadi concludes the article "Do electrons really exist" with 
"The answer and interpretation that is given to the original question of 'Do 
electrons really exist?' is therefore a reflection of the individual's 
philosophy of science and ultimately their stance on the nature of reality." 
which is correct.  In this note we start with this conclusion and look at what 
motivates one stance above another.

	Mashhadi points out that "really exists" has different meanings in 
three different philosophical schools. [1]  What these schools might say 
about the ontological status of electrons might be summarized:

_Positivists_: does the theory of electrons make correct predictions? 
_Instrumentalists/Pragmatists (I/P)_: "electron" is a convenient fiction for 
     coordinating the results of observations.
_Realist_: electrons exist independently of theories they exist outside our 
     minds/experiences.

	These different answers arise mainly because the different 
philosophical systems emphasize different aspects of the word "reality". In 
an abbreviated way we may say what the systems are preoccupied with:

_Positivists_: the meaning [of a scientific claim] is its method of 
     verification.
_I/P_: does it work? Is it useful?
_Realist_: does an electron exist independently of the experimenter?


	Yet we come to an essential distinction for Realists.  Books and 
tables seem to have nice properties of independent existence.  Whatever kind 
of objective existence books and tables have we may say is expounded by 
*Classical Realism*.  Yet it is very well known that Classical Realism is 
untenable when it comes to quantum systems.  We may take the example of an 
electron.

	An electron does *not have any properties at all* in the Classical 
Realistic sense *until* a quantum mechanical observation/measurement is made.  
Even if an observable of the electron is known to be in one particular 
eigenstate E, so that the probability of obtaining E's particular eigenvalue 
upon measurement is identically one, it is *not* true that the electron has a 
property (observable) whose value is the eigenvalue of E.  Rather the electron 
is 'in a superposition of one state.' [2]  *Only* at measurement (and indeed 
only for the measuring system) does the electron acquire properties in the 
sense of Classical Realism (though it is not clear that even then the 
properties measured are exactly those of the classical sense.) 

	Thus Classical Realism is untenable in the case of quantum systems.  
Yet some would assert that the probability wave packet does exist "out there" 
in some sense independent of observations, physicists, and minds.  This might 
be called Quantum Realism.  A *Quantum Realist* would assert that a quantum 
system ontologically exists in a sense independent of people whatever a 
quantum system happens to be.

	The apparent change of state of quantum systems upon observation 
from spooky entangled superpositions to things that have values of observables 
and back again need not pose problems for the Quantum Realist because these may 
be included in the definition of quantum system.  The Quantum Realist does not 
assert that quantum things are classical things, but that objects of quantum 
theory refer to things outside both the theory and the experimenter's own 
experience.	

	A Realist may be a Classical Realist in the classical realm of things 
and a Quantum Realist in the quantum realm of things.  Given this definition 
of Realist, we may ask why the different philosophies have not come to a 
consensus regarding the reality of electrons?  My question really is: what is 
the most reasonable stance from a common-sense point of view?

	Positivists would define "electron" as a (certain set of) series of 
procedures.  I am not very satisfied with this.  We are more than zombies; 
what about comprehension?  If there were no possibility of comprehending the 
universe no one would do physics.  Clearly physicists really seem to be on to 
something in existence beyond procedures. 

	I/P would say "electron" is a coordinator of experiments.  Yet this 
definition suffers from the same problems as the Positivists'.  Further, there 
is the imminent question: why are there regularities found in nature?  If all 
'objects' are really just indicators of regularities it is not at all clear 
how anything is supposed to exist in the first place.

	Of course the Realist gets around these problems by postulating the 
existence of independent physical 'stuff'.  But here is a serious problem.  
This postulation takes the form of what I have called the *Hypothesis of 
Objective Existence* (HOE). [3]  We only have access to a finite number of 
observations/experiments/sensations.  Thus we can never prove that an object, 
which can only be *hypothesized* to exist, has the properties we ascribe to it.  
A typical property is that the object (like a couch) will still be there if I 
leave the room.  One of the properties for a Quantum Realist is that a quantum 
probability amplitude *actually* possesses the *possibility* of being observed 
in this or that eigenstate.  Another could be that the electron continues to 
evolve by the Schroedinger equation when I leave the laboratory.  A third, very 
significantly, is that if *someone else* were to measure an electron s/he would 
have the same chance of finding certain eigenvalues as myself.

	The problem is that the Realist can *never know* that s/he is right.  
Even with a theory of everything in hand, the Realist cannot know the theory 
to be true and in principle could be proved wrong by experiment tomorrow.  
Further, sensations are not a part of theories -- a theory of everything will 
be experientially only an idea.  This lends credence to the mystic's assertion 
that theories do not lend themselves to an appreciation of ultimate reality.  

	HOE *must* be regarded with skepticism.  Quantum mechanics itself showed 
the classical HOE to be false (at least on microscopic scales.)  It could be that 
the problems in reconciling general relativity with quantum mechanics stem 
from quantum realism i.e. the quantum HOE.	

	Are we left with nothing regarding the question of the existence of 
electrons? I think the most reasonable view would be to adopt the 
self-explanatory *Provisional Realism*.  We are for the most part aware that 
"electron" may be negated in a future theory.  One must also be aware that 
HOE itself is only a hypothesis--which may one day be inconsistent with the 
evidence. 

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

[1]  Mashhadi, Azam. Metaphysical Review, July 1997.

[2] This has always been my understanding.  I am aware that recently the 
Kochen-Specker Paradox has been used to prove this, but I cannot find the 
reference.

[3] Merriam, Paul.  Preprints.  Justifying Dualism to Monists also uses HOE 
and therefore has the same problems.