# RUSSELL HANSON, DAVID BOHM AND OTHERS ON THE SEMANTICS OF DISCOVERY

## BOOK VII - Page 1

Norwood Russell
Hanson (1924-1967), born in New Jersey, was a U.S. Marine Corps
fighter pilot during the Second World War, who earned the rank
of major, and was awarded the Distinguished Flying Cross and the
Air Medal for flying combat missions over Japan. Afterward
he studied at the University of Chicago, Columbia University,
and Yale University in the United States, and then studied at
both Oxford University and Cambridge University in England.
He received an M.A. from Oxford and a Ph.D. from Cambridge in
1956, and was afterward a fellow at the Institute for Advanced
Study at Princeton. He accepted a faculty appointment at
Indiana University in 1957, where he was founder and chairman of
Indiana University's Department of History and Logic of Science
from 1960 to 1963. He then accepted a professorship on the
philosophy department faculty of Yale University, which he had
at the time of his premature death at the age of forty three in
a crash of his private airplane in 1967. His principal
works are *Patterns of Discovery* (1958) and *Concept of
the Positron *(1963). At the time of his death he left
an uncompleted textbook in philosophy of science intended for
first-year college students, which was edited by Willard C.
Humphreys, a former student of Hanson, and then published as *
Perception and Discovery* (1969). A year after his
death a complete bibliography of his publications appeared in a
memorial volume of *Boston Studies in the Philosophy of
Science*, Volume III (1968).

David Bohm (1917-1992) was born in Wilkes-Barre, PA, and
received his doctorate in physics from the University of
California. He taught physics at Princeton, and eventually
moved to England. He was professor of theoretical physics
from 1961 at Birkbeck College, University of London, where he
was professor emeritus from 1983 until his death in 1992.
A brief biography may be found in the "General Introduction" in
*Quantum Implications* (ed. B.J. Hiley and F. David Peat,
1987), and a three-hundred-fifty page biography by David Peat
was later published under the title *Infinite Potential: The
Life and Times of David Bohm* (1997). Bohm’s initial
statement of his hidden-variable interpretation of quantum
theory was published in 1952 in two articles in the *Physical
Review*, in which he reports that the interpretation was
originally stimulated by a discussion with Einstein in 1951. His
principal statements of his hidden-variable interpretation of
quantum theory are set forth in two of his books. The
earlier is a brief monograph of only one-hundred-forty pages
titled* Causality and Chance in Modern Physics *published
in 1957, and the more recent is his more elaborate *Undivided
Universe* co-authored with Basil Hiley and posthumously
published in 1993. After publishing his seminal articles in
1952, he found that his interpretation had been anticipated in
important respects in 1927 by Louis de Broglie (1892-1987).
De Broglie's interpretation had been criticized severely, and he
had consequently abandoned it, but Bohm had further developed
the thesis enough that the fundamental objections confronting de
Broglie had been answered. Bohm's interpretation was shown
to be consistent with all the experimentally detectable effects
then known about of the quantum phenomena, and additional
suggestions were made by Vigier, a colleague of de Broglie.
De Broglie then returned to his original proposals, since he
believed that the decisive objections against them had been
answered. Bohm and Vigier afterwards published a joint
paper setting forth the interpretation in the *Physical Review
*in 1954, and de Broglie wrote a "Foreword" to Bohm's 1957
book. Bohm was one of the physicists who recognized
nonlocality (a.k.a. entanglement) in the quantum theory.
Peat’s generally sympathetic biography shows how the idea of
nonlocality led Bohm firstly to his wholistic ontology for
physics, then to his process metaphysics, and finally to his
mysticism of the implicate order, according to which mind and
matter are indivisibly united. To the dismay and
consternation of his friends and colleagues, this mysticism was
encouraged by Bohm’s long-time association with an Indian guru,
and also led Bohm to take seriously the mind-over-matter
exhibitions of a stage magician.

Hanson takes very seriously issues about the interpretation of
the modern quantum theory, and he truculently defends the
Copenhagen interpretation. In “Appendix II” to his*
Patterns of Discovery *he notes that while for most practical
microphysical problems Born, who accepted the Copenhagen
interpretation, and Schrödinger, who did not, would have made
the same theoretical calculations. Nevertheless, their
alternative interpretations organized their thinking
differently, and consequently influenced their future research
work in very different ways. After 1930 Born was led to
work on collision behavior, on the statistical analysis of
scattering matrices, while Schrödinger pursued investigation of
the so-called ghost waves of the elementary particles. The
interpretations, therefore, are important because each supplies
an agenda that influences the direction of future research in
physics.

But Hanson does not view all interpretations as equally worthy of consideration, and one that he considers particularly unfortunate is the "hidden-variable" interpretation developed by David Bohm. In contrast to the Copenhagen interpretation with its duality thesis that the wave and particle are two manifestations of the same physical entity, Bohm’s alternative interpretation is that the wave and particle are different physical entities, even though they are never found separately. Furthermore it says that the wave oscillates in an as yet experimentally undetected and therefore hidden subquantum field. In the context of the topic of scientific discovery Bohm’s views are interesting, because they illustrate the semantical approach to scientific discovery and to the development of theory in physics. His views illustrate the use of linguistic figures of speech as a technique for theory development based on certain postulated basic similarities between phenomena at the macrophysical and microphysical orders of magnitude, similarities that are denied by advocates of the Copenhagen interpretation. But firstly consider Bohm’s early advocacy of the Copenhagen interpretation, and then turn to his later agenda for future physics including his hidden-variable alternative to the Copenhagen interpretation for quantum theory.

**Bohm's Early Copenhagen Views**

The hidden-variable thesis is Bohm’s more mature view. He
started out as an advocate of the Copenhagen interpretation,
which he also calls the “usual” interpretation, and then changed
his mind after the talk with Einstein in 1951, the year in which
his textbook titled *Quantum Theory* was published setting
forth his earlier view. There are at least two noteworthy
features of this early book. The first is Bohm’s distorted
understanding of Bohr’s philosophy of quantum theory. The
second is his ontology for quantum theory, the ontology of
potentialities, which anticipated Heisenberg’s similar ontology
of *potentia* by seven years.

In the “Preface” to his *Quantum Theory *Bohm says that as
a result of the work of Neils Bohr, it has become possible to
express the results of quantum theory in terms of comparatively
qualitative and imaginative concepts, which are totally
different from those appearing in the classical theory. He
rejects the view that the quantum properties of matter imply the
renunciation of the possibility of these properties being
understood in the customary imaginative sense, and that they
only imply the sufficiency of only a self-consistent
mathematical formalism, which can in some mysterious way
correctly predict the numerical results of experiments.
The eighth chapter of the book is titled “An Attempt to Build a
Physical Picture of the Quantum Nature of Matter”, and Bohm
writes in a footnote that many of the ideas appearing in the
chapter are an elaboration of material in Bohr’s *Atomic
Theory and the Description of Matter*. However, Bohm’s
understanding of Bohr is distorted. Bohr maintained an
instrumentalist view of the equations of quantum theory, which
rejects any semantics or ontology for quantum theory, and he
repeatedly denied explicitly that quantum phenomena are
pictureable. From Bohm’s statement in his 1952 articles that his
hidden-variables thesis was the result of a talk with Einstein
in 1951, it is reasonable to speculate that Einstein had read
Bohm’s book, had recognized that Bohm was ripe for
disillusionment with the views in Bohr’s philosophy, and had
concluded that Bohm was ready for induction into the ranks of
Bohr’s critics. In any event whatever may have been
Einstein’s unreported comments to Bohm in their private
conversation, the ultimate forty years later was Bohm’s *
Undivided Universe: An Ontological Interpretation of Quantum
Theory* (1973), a book in which Bohm explicitly says he is
supplying an ontology to replace the epistemological
interpretation he thought he had found in Bohr’s writings.

The ontology for quantum theory that Bohm described in 1951 is a wholistic ontology of potentialities, in which the world is an indivisible unit where quanta have no component parts describable by hidden variables, and are not even separate objects, but are only a way of talking about indivisible transitions. This metaphysics is also called monism. At the quantum-mechanical level the properties of a given object do not exist separately in the quantum object alone, but rather are potentialities which are realized in a way that depends on the systems with which the object interacts. Thus the electron has the potentiality for developing either its particle-like or its wave-like form, depending on whether it interacts with an apparatus that measures either its position or momentum. Bohm’s views are also realist; he does not maintain that the quantum phenomenon has its properties because it is being measured. He says that a quantum-mechanical system can produce classically describable effects not only in a measuring apparatus, but also in all kinds of systems that are not actually being used for the purpose of making measurements. Throughout the process of measurement the potentialities of the electron change in a continuous way, while the forms in which these potentialities can be realized are discrete. The continuously changing potentialities and the discontinuous forms in which the potentialities may be realized are complementary properties of the electron.

Bohm anticipated Heisenberg’s idea of potentiality, which
Heisenberg did not propose until his *Physics and Philosophy*
in 1958, the only place in Heisenberg’s literary corpus where
the idea is mentioned. But there are differences in their ideas
of potentiality, because unlike Bohm’s, Heisenberg’s is not a
wholistic version. In the 1951 book Bohm said that
potentiality makes quantum theory inconsistent with the
hidden-variables thesis, because the hidden-variables view is
based on the incorrect assumption that there are separately
existing and precisely defined elements of reality. The
idea of potentiality is much more integral to Bohm’s earlier
interpretation than to Heisenberg’s, and it had distinctive
implications for Bohm. One implication is Bohm’s thesis
that mathematics is inadequate for physics. He says that
the interpretation of the properties of the electron as
incompletely defined potentialities finds its mathematical
reflection in the fact that the wave function does not
completely determine its own interpretation until it interacts
with the measuring device, and that the wave function is not in
one-to-one correspondence with the actual behavior of matter,
but is merely an abstraction reflecting only certain aspects of
reality. He believes that to obtain a description of all
aspects of the world, one must supplement the mathematical
description with a physical interpretation in terms of the
incompletely defined potentialities.

Shortly afterwards he accepted the hidden-variables idea, and in
the second chapter of his *Undivided Universe*, where he
mentions in a footnote his anticipation of Heisenberg’s idea of
potentiality, he rejects altogether the potentiality thesis that
the particle itself is created by the measurement process.
In Bohm’s hidden-variables view, the particle is not a
wave-packet or otherwise created out of the wave; the particle
is in reality distinct from the wave. His later view is
not wave *or* particle, but wave *and* particle.
That is, the wave and particle are not two alternative aspects
of the same entity, but are different and separate entities.

**Bohm's Agenda for Future
Microphysics**

Bohm's hidden-variable interpretation is an agenda for future
microphysics, and his *Causality and Chance* (1957) sets
forth three related objectives in this agenda. His *
first objective* is the relatively modest one of
demonstrating that an alternative to the Copenhagen
interpretation is possible, in the sense that it is not the only
one that is consistent with the formalism and measurements of
quantum theory. He states this objective not only because
he has another interpretation in mind, but also because he
maintains that the development of alternative views is important
for the advancement of science, while advocates of the
Copenhagen interpretation deny that any alternative view
including one involving a subquantum order of magnitude is
conceivable. For example in his "Questions of Principle in
Modern Physics" (1935) in *Philosophical Problems of Quantum
Physics* Heisenberg states that the indeterminacy principle
must be taken as a question of principle making other
formulations into false and meaningless questions, just as in
relativity theory it is supposed that it is in principle
impossible to transmit signals at speeds greater than the
velocity of light. But Bohm maintains that without
alternatives the physicist is constrained to work along accepted
lines of thought in the hope that either new experimental
developments or new theoretical insights will eventually lead to
a new theory. Bohm maintains that one of the functions of
criticism in physics is to suggest alternative lines of research
that are likely to lead in a productive direction. He thus
sees criticism with alternatives to be integral to scientific
discovery. This objective is particularly attractive to
the philosopher of science Paul Feyerabend, once an advocate of
Bohm's interpretation, who to the end of his life maintained
that creating alternatives is necessary for advancement.

Bohm's *second objective* is to propose an interpretation
of the history of physics, which shows successful precedents for
the research strategy represented by his hidden-variable
interpretation of quantum theory. The paradigmatic
precedent he invokes is the atomic theory of matter, which
postulated the existence of atoms unobservable at the time the
theory was proposed. Analogously Bohm’s strategy consists
of postulating that there exists an order of physical magnitude
below the quantum order of magnitude containing the quantum of
action represented by Planck's constant. Bohm postulates
that this subquantum order contains qualitatively different
types of phenomena governed by more deterministic laws than do
those known to exist at the quantum order of magnitude.
The existence of this postulated subquantum order of
microphysical phenomena is denied by the Copenhagen
interpretation advocates, and since there was no experimental
detection of any such subquantum phenomena, the theory that
postulates them is said to have “hidden variables”.

Bohm opposes his historical interpretation to another that he calls “mechanistic”, a term that is unfortunately ambiguous in both philosophical and scientific usage, but which has a specific and somewhat elaborate meaning in Bohm’s book. According to the objectionable mechanistic philosophy opposed by Bohm the qualitative diversity of things in the world can be reduced completely, without approximation, and in every possible domain of science to nothing more than the effects of some definite and limited general framework of quantitative laws, which are regarded as absolute and final. Prior to the development of quantum theory these quantitative laws were assumed to be deterministic; then later with the development of the Copenhagen interpretation of quantum theory these laws were assumed to be nondeterministic. Hence there are both deterministic and nondeterministic varieties of mechanism. In the former variety causal laws are thought to be fundamental, while in the latter probability laws are thought to be fundamental. Nondeterministic mechanism prevails today, because physicists have accepted Heisenberg's thesis that the indeterminacy principle represents an absolute and final limitation on our ability ever to define the state of things by measurement.

In *Causality and Chance* Bohm maintains that causality and
chance are both fundamental and objective, and that both
determinism and nondeterminism are merely idealizations.
Thus he rejects Einstein's determinism. He also rejects
the subjective interpretation of probability, which says that
the appearance of chance is a result of human ignorance.
And he rejects the idea common to both deterministic and
nondeterministic varieties of mechanism that there is only one
general framework of laws and a limited qualitative diversity.
Bohm maintains that there are different orders of magnitude with
each level having its own laws and qualitative diversity.
In the history of physics revolutionary developments have
occurred when those of a lower level explain laws and qualities
at a higher level. Experiments may disclose a breakdown of
an entire scheme of laws by the appearance of chance
fluctuations not originating in anything at the higher level,
but instead originating in qualitatively different kinds of
factors at a lower level. For example in classical physics
a particle such as an electron follows the classical orbit only
approximately, while in a more accurate treatment it is found to
undergo random fluctuations in its motions arising outside the
context of the classical level. Thus Bohm affirms by way of
historical analogy and on the basis of his nonmechanistic
interpretation of the history of science that there is a deeper
subquantum order of magnitude, which in turn explains the
randomness that is detected at the higher quantum order of
magnitude.

Bohm’s hidden-variable interpretation is an alternative interpretation of quantum theory motivated both by this prior ontological commitment to a subquantum order and by a discovery heuristic for which there is historical precedent. He maintains that new work is considerably facilitated by his thesis of a hidden subquantum order, because the physicist can imagine what is happening, and can thereby be led to new ideas not only by looking directly for new equations but also by a related procedure of thinking in terms of concepts and models that will help to suggest new equations that would not likely be suggested by mathematics alone. And he uses his postulated subquantum ontology as a basis for linguistic figures of speech such as analogy, which are a central feature in his discovery strategy. These figures of speech aid in formulating new hypotheses for future physics both on the basis of similarities between the macrophysical and microphysical orders of magnitude and on the basis of past developments in the history of physics, which he believes justifies his hidden-variables ontology.

Finally Bohm's *third objective* is to use the
hidden-variable interpretation as a guide for future research
for a new microphysical theory that will resolve what he sees as
the current crisis in quantum physics. This crisis
manifests itself in Dirac's relativistic quantum theory, when
the wave equation is applied to the description of particle
scattering with very high energies and at short distances.
For the Schrödinger wave equation to be used in such
applications, an *ad hoc* mathematical adjustment called
“renormalization” is necessary. Furthermore the behavior
of very high-energy particles in experiments reveals that there
exist many new kinds of particles not previously known, and that
they are unstable, since they decay into one another and create
other particles. Nothing like this is accounted for by
current quantum theory. To Bohm these problems for the
current quantum theory suggest that elementary particles are not
really elementary. The concept of a subquantum level justifies
the physicist considering a whole range of qualitatively new
kinds of theories that approach the currently accepted theory
only as approximations that hold in limiting cases. He
believes that the current crisis in quantum theory portends a
revolution in microphysics, and that his hidden-variable
interpretation offers a superior guide for research that
promises to resolve the crisis.

In summary these three objectives of Bohm's agenda represent
successively more ambitious claims. The first claim is
merely that an alternative to the Copenhagen semantical
interpretation describing a subquantum level of magnitude is
conceivable in the sense that it is consistent with the data and
formalism of the current quantum theory. The second claim
states more ambitiously that the history of physics reveals that
postulating lower levels of magnitude supplies an analogy, which
is a productive strategy to guide new research. The third
claim is still more ambitious; it states that a new scientific
revolution in microphysics is at hand, and that the
hidden-variable semantical interpretation will produce a new
microphysical theory that will resolve the current crisis in
quantum theory. As de Broglie said in the closing sentence
of his "Foreword" to *Causality and Chance* (1957), Bohm's
book comes at exactly the right time. Thirty-five years
later in his *Undivided Universe* Bohm was still predicting
this impending revolution. More recent experiments based
on John Stuart Bell’s inequality have occasioned reconsideration
of the merits of Bohmian mechanics. But if there has been
any revolution since those days, it has been the quite different
string theory.

Pages [1] [2]
[3] [4]
[5] [6]
[7]

**NOTE: Pages do not corresponds
with the actual pages from the book**