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Brian D. Josephson
Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE, England.

(Published in `The Relationship Between Mind and Matter', ed. B. Rubik.
(c) the Center for Frontier Sciences at Temple University).


This paper examines the processes involved in attempting to capture the
subtlest aspects of nature by the scientific method and argues on this basis
that nature is fundamentally elusive and may resist grasping by the methods
of science.  If we wish to come to terms with this resistance, then a shift
in the direction of taking direct experience into account may be necessary
for science's future complete development.

What is matter and what is mind?  Ren\'e Descartes regarded these entities
as being of totally different orders and completely separate from each
other, although nowadays the conventional view is to consider mind function
as reducible to the behaviour of matter. In this paper I want to propose a
new theme in the mind-matter problem, with an approach that considers what I
shall call the elusivity or elusive quality of nature.  The fundamental idea
is that nature at large is less amenable to being pinned down to a precise
description than the successes of science to date may seem to imply,
particularly if we consider science as applying to some `objective reality'
that is independent of the scientist.  Some phenomena are more elusive to
the methods of ordinary science than others, as will be explained in terms
of a series of examples in what follows.  Mind may be especially elusive and
it will be suggested in the course of this paper that as far as the
phenomena of mind go, there is no good reason to suppose that a proper
description in terms of the usual methods of science can be obtained at all.
To deal with this situation it may prove necessary to use subtler
methodologies, such as entering into the subtleties of conscious experience
directly, as is the way of the mystic or of the practitioner of the arts.

To illustrate the concept of elusivity, let us focus on the problem of
knowing precisely where a given object is located.  The least elusive
entities are classical macroscopic objects.  The position of such an object
relative to a given reference frame can be typically measured by means of a
ruler, or by means of the techniques of the surveyor, depending on on the
length scales involved (or by more advanced methods such as those involving
lasers if high accuracy is desired).  If, however, the object is moving then
the question of its position becomes problematic, as in the case of the Zeno
paradox.  If the velocity is very low then the concept of the current
position has meaning. However, if the motion is rapid the concept of `now'
is not well enough defined to make the position `now' meaningful.  In such a
case the concept of the time (coupled with the physical apparatus of the
clock that gives a measure to this variable) becomes necessary in order to
be able to determine and define the position of the object at particular
instant of time which is of interest. Defining this elusive quantity (the
position) requires the use of additional apparatus such as a high-speed
shutter or light source to `freeze' the position and make it definite.

In the microscopic domain, we never determine the position of a high- speed
fundamental particle at a given moment of absolute time at all, but only
measure its trajectory.  In the quantum domain, elusiveness becomes a
fundamental feature of nature since the uncertainty principle sets definite
limits to our ability (even in principle) to determine the position of a
particle over a period of time of finite duration.  Nature in this regime
behaves rather like an insect that reponds to our attempts to swat it,
utilising a determination of just where it will be at the appropriate future
instant, by changing its position.  This ensures that our prediction will be
incorrect, with the result that the insect survives our attempts to dispose
of it.

Arguments can be given (Josephson 1988) that in the real world (i.e. the
world outside the domain of the scientific laboratory) nature may be still
more elusive than this.   Detailed analysis and discussion of arguments due
originally to Niels Bohr would appear to show that in general any attempt to
discover the essence of a naturally occurring system in such detail as to be
able to describe it within a quantum mechanical framework (viz. by assigning
to it a wave function or a density matrix) will lead to such an alteration
of the characteristics of the system under study that it will no longer be
possible to regard it as being applicable to the original system. Again, it
may be noted that the phenomenon of deterministic chaos (Gleick 1988) points
equally to the existence of unavoidable limitations to the attempt to pin
down nature and say exactly what it is.

Thus some aspects of nature are more amenable to the way of present-day
science than are others.  We can start to see mind, in its subtler aspects
especially, as something which cannot necessarily be handled in terms of the
kind of methods and descriptions that we are used to using in the world of
science. Even if it is in fact legitimate to equate the workings of the mind
with the behaviour of the brain, the question of what exactly the brain is
will present us with grave difficulties, even in principle, if we ask
questions about it at a sufficiently subtle level.

But these traditional methods of science, at least for the hard sciences,
take little or no account of conscious experience, which is regarded as an
epiphenomenon that science does not have to take account of at all.  Yet our
own experiences are in general less elusive to us than are the subtler
phenomena of modern science.  It may thus be argued that if we are to
understand the mind fully then science needs to take fuller account of the
phenomena of conscious experience.  In this respect, conscious experience is
usually considered to be a subjective affair and thus unsuitable for meeting
the requirements of science.  I believe this to be a mistaken view of the
situation.  Artists and mystics have, in some cases, described their
conscious experiences in great detail, and I see no reasons (other than
custom and ideology) why these should not be taken into account in
assembling our world-view.  A closely related topic is the question of
meaning, which David Bohm has suggested (Pylkk\"anen 1989) constitutes a
fundamental aspect of reality.  Again, in the arts we find meaning to have
dimensions that the methods of reasoning employed in science have yet to
discover (Langer 1957).

I will conclude by suggesting that if we wish to come to terms with the
resistance that the natural world appears to have to being grasped by the
methods of science, then a shift in the direction of taking into account
direct experience may be necessary for the future development of science,
although this will necessarily entail a drastic shift in regard to what it
is regarded as being appropriate areas of exploration for the scientist.

I am grateful to Prof. S.M. Rosen for discussions of experiential knowledge.


Gleick, J. (1988), Chaos, Heinemann, London.

Josephson, B.D. (1988), Found. Phys. 18, 1195-1204.

Langer, S.K. (1957), Philosophy in a New Key, Harvard, London and
Cambridge, Mass.

P. Pylkk\"anen (1989), ed., The Search for Meaning, (Crucible,
Wellingborough, Northants., UK, 1989).