Science
in Christian PerspectiveScience
in Christian Perspective
Life's Irreducible Structure*
MICHAEL POLANYI
Emeritus Professor of Social Studies
University of Manchester, England
Response by Richard H. Bube and Colin Duriez
*Michael Polanyi is a former Fellow of Merton College, Oxford, and
Emeritus Professor
of social studies at the University of Manchester, where he had previously held
the Chair of Physical Chemistry. This article is reprinted from
Science 160, 1308
(1968), copyright 1968 by the American Association for the
Advancement of Science.
It is published in Knowing and Being: Essays by Michael Polonyi,
edited by Majorie
Creoe (Chicago: University of Chicago Press, 1969)
From: JASA 22 (December 1970): 123-131.
Boundary Conditions
If all men were exterminated, this would not affect the laws of
inanimate nature.
But the production of machines would stop, and not until men arose again could
machines be formed once more. Some animals can produce tools, but only men can
construct machines; machines are human artifacts, made of inanimate
material.
The Oxford Dictionary describes a machine as "an apparatus for applying mechanical power, consisting of a number of interrelated parts, each having a definite function." It might be, for example, a machine for sewing or printing. Let us asume that the power driving the machine is built in, and disregard the fact that it has to be renewed from time to time. We can say, then, that the manufacture of a machine consists in cutting suitably shaped parts and fitting them together so that their joint mechanical action should serve a possible human purpose.
The structure of machines and the working of their structure are thus shaped by
man, even while their material and the forces that operate them obey the laws
of inanimate nature. In constructing a machine and supplying it with power, we
harness the laws of nature at work in its material and in its driving force and
make them serve our purpose.
This harness is not unbreakable; the structure of the machine, and
thus its working,
can break down. But this will not affect the forces of inanimate
nature on which
the operation of the machine relied; it merely releases them from the
restriction
the machine imposed on them before it broke down
So the machine as a whole works under the control of two distinct principles.
The higher one is the principle of the machine's design, and this harnesses the
lower one, which consists in the physical-chemical processes on which
the machine
relies. We commonly form such a twoleveled structure in conducting an
experiment;
but there is a difference between constructing a machine and rigging
u an experiment.
The experimenter imposes restrictions on nature in order to observe
its behavior
under these restrictions, while the constructor of a machine restricts nature in order to harness its workings. But
we may borrow a term from physics and describe both these useful restrictions
of nature as the imposing of boundary conditions on the laws of
physics and chemistry.
Let me enlarge on this. I have exemplified two types of boundaries.
In the machine
our principal interest lay in the effects of the boundary conditions, while in
an experimental setting we are interested in the natural processes controlled
by the boundaries. There are many common examples of both types of boundaries.
When a saucepan bounds a soup that we are cooking, we are interested
in the soup;
and likewise, when we observe a reaction in a test tube, we are
studying the reaction,
not the test tube. The reverse is true for a game of chess. The strategy of the
player imposes boundaries on the several moves, which follow the laws of chess,
but our interest lies in the boundaries-that is, in the strategy, not
in the several
moves as exemphfications of the laws. And similarly, when a sculptor shapes a
stone or a painter composes a painting, our interest lies in the
boundaries imposed
on a material, and not in the material itself.
The organism is shown to be, like a machine, a system which works according to two different principles: its structure serves as a boundary condition harnessing the physical-chemical processes by which its organs perform their functions.
We can distinguish these two types of boundaries by saying that the
first represents
a test-tube type of boundary whereas the second is of the machine
type. By shifting
our attention, we may sometimes change a boundary from one type to another.
All communications form a machine type of boundary, and these boundaries form
a whole hierarchy of consecutive levels of action. A vocabulary sets boundary
conditions on the utterance of the spoken voice; a grammar harnesses words to
form sentences, and the sentences are shaped into a text which
conveys a communication.
At all these stages we are interested in the boundaries imposed by a
comprehensive
restrictive power, rather than in the principles harnessed by them.
Living Mechanisms Are Classed with Machines
From machines we pass to living beings, by remembering that animals move about
mechanically and that they have internal organs which perform functions as parts of a machine do-functions which sustain the life of the organism, much as
the proper functioning of parts of a machine keeps the machine going.
For centuries
past, the workings of life have been likened to the workings of
machines and physiology
has been seeking to interpret the organism as a complex network of mechanisms.
Organs are, accordingly, defined by their life-preserving functions.
Any coherent part of the organism is indeed puzzling to
physiology-and also meaningless
to pathology-until the way it benefits the organism is discovered.
And I may add
that any description of such a system in terms of its
physical-chemical topography
is meaningless, except for the fact that the description covertly may
recall the
system's physiological interpretation-much as the topography of a
machine is meaningless
until we guess how the device works, and for what purpose.
In this light the organism is shown to be, like a machine, a system which works
according to two different principles: its structure serves as a
boundary condition
harnessing the physicalchemical processes by which its organs perform
their functions.
Thus, this system may be called a system under dual control. Morphogenesis, the
process by which the structure of living beings develops, can then be likened
to the shaping of a machine which will act as a boundary for the laws
of inanimate
nature. For just as these laws serve the machine, so they serve also
the developed
organism.
A boundary condition is always extraneous to the process which it delimits. In
Galileo's experiments on balls rolling down a slope, the angle of the slope was
not derived from the laws of mechanics, but was chosen by Galileo. And as this
choice of slopes was extraneous to the laws of mechanics, so is the shape and
manufacture of test tubes extraneous to the laws of chemistry.
The same thing holds for machinelike boundaries; their structure
cannot be defined
in terms of the laws which they harness. Nor can a vocabulary
determine the content
of a text, and so on. Therefore, if the structure of living things is a set of
boundary conditions, this structure is extraneous to the laws of
physics and chemistry
which the organism is harnessing. Thus the morphology of living thing
transcends
the laws of physics and chemistry.
DNA Information Generates Mechanisms
But the analogy between machine components and live functioning
organisms is weakened
by the fact that the organs are not shaped artificially as the parts
of a machine
are. It is an advantage, therefore, to find that the morphogenetic process is
explained in principle by the transmission of information stored in
DNA, interpreted
in this sense by Watson and Crick.
A DNA molecule is said to represent a code-that is, a linear sequence of items,
the arrangement of which is the information conveyed by the code. To the case
of DNA, each item of the series consists of one out of four alternative organic
bases.' Such a code will convey the maximum amount of information if the four
organic bases have equal probability of forming any particular item
of the series.
Any difference in the binding of the four alternative bases, whether
at the same
point of the series, or between two points of the series, will cause
the information
conveyed by the series to fall below the ideal maximum. The information content
of DNA is in fact known to be reduced to some extent by redundancy,
but I accept
here the assumption of Watson and Crick that this redundancy does not prevent DNA from
effectively functioning as a code. I accordingly disregard, for the
sake of brevity,
the redundancy in the DNA code and talk of it as if it were
functioning optimally,
with all of its alternative basic bindings having the same
probability of occurenee.
Let us he clear what would happen in the opposite case. Suppose that the actual
structure of a DNA molecule were due to the fact that the bindings of its bases
were much stronger than the bindings would be for any other
distribution of bases,
then such a DNA molecule would have no information content. Its
codelike character
would be effaced by an overwhelming redundancy.
We may note that such is actually the case for an ordinary chemical molecule.
Since its orderly structure is due to a maximum of stability, corresponding to
a minimum of potential energy, its orderliness lacks the capacity to function
as a code. The pattern of atoms forming a crystal is another instance
of complex
order without appreciable information content.
There is a kind of stability which often opposes the stabilizing
force of a potential
energy. When a liquid evaporates, this can be understood as the
increase of entropy
accompanying the dispersion of its particles. One takes this
dispersive tendency
into account by adding its powers to those of potential energy, but
the correction
is negligible for cases of deep drops in potential energy or for low
temperatures,
or for both. We can disregard it, to simplify matters, and say that
chemical structures
established by the stabilizing powers of chemical bonding have no appreciable
information content.
The morphology of living things transcends the laws of physics and chemistry.
In the light of the current theory of evolution, the codehke structure of DNA
must be assumed to have come about by a sequence of chance variations
established
by natural selection. But this evolutionary aspect is irrelevant here; whatever
may be the origin of a DNA configuration, it can function as a code only if its
order is not due to the forces of potential energy. It must be as
physically indeterminate
as the sequence of words is on a printed page. As the arrangement of a printed
page is extraneous to the chemistry of the printed page, so is the
base sequence
in a DNA molecule extraneous to the chemical forces at work in the
DNA molecule.
It is this physical indeterminacy of the sequence that produces the
improbability
of occurrence of any particular sequence and thereby enables it to
have a meaning-a
meaning that has a mathematically determinate information content equal to the
numerical improbability of the arrangement.
DNA Acts as a Blueprint
But there remains a fundamental point to be considered. A printed page may be
a mere jumble of words, and it has then no information content. So
the improbability
count gives the possible, rather than the actual, information content of a page. And this applies also to
the information
content attributed to a DNA molecule; the sequence of the bases is
deemed meaningful
only because we assume with Watson and Crick that this arrangement
generates the
structure of the offspring by endowing it with its own information content.
This brings us at last to the point that I aimed at when I undertook to analyze
the information content of DNA: Can the control of morphogenesis by
DNA he likened
to the designing and shaping of a machine by the engineer? We have
seen that physiology
interprets the organism as a complex network of mechanisms, and that
an organism
is-like a machine-a system under dual control. Its structure is that
of a boundary
condition harnessing the physical-chemical substances within the
organism in the
service of physiological functions. Thus, in generating an organism,
DNA initiates
and controls the growth of a mechanism that will work as a boundary condition
within a system under dual control.
And I may add that DNA itself is such a system, since every system
conveying information
is under dual control, for every such system restricts and orders, in
the service
of conveying its information, extensive resources of particulars that
would otherwise
be left at random, and thereby acts as a boundary condition. In the case of DNA
this boundary condition is a blueprint of the growing organism.2
We can conclude that in each embryonic cell there is present the duplicate of
a DNA molecule having a linear arrangement of its bases-an arrangement which,
being independent of the chemical forces within the DNA molecules,
conveys a rich
amount of meaningful information. And we see that when this
information is shaping
the growing embryo, it produces in it boundary conditions which,
themselves being
independent of the physical chemical forces in which they are rooted, control
the mechanism of life in the developed organism.
To elucidate this transmission is a major task of biologists today, to which I
shall return.
Some Accessory Problems Arise Here
We have seen boundary conditions introducing principles not capable
of formulation
in terms of physics or chemistry into inanimate artifacts and living things; we
have seen them as necessary to an information content in a printed page or in
DNA, and as introducing mechanical principles into machines as well as into the
mechanisms of life.
Let me add now that boundary conditions of inanimate systems established by the
history of the universe are found in the domains of geology,
geography, and astronomy,
but that these do not form systems of dual control. They resemble in
this respect
the test-tube type of boundaries of which I spoke above. Hence the existence of
dual control in machines and living mechanisms represents a
discontinuity between
machines and living things on the one hand and inanimate nature on
the other hand,
so that both machines and living mechanisms are irreducible to the
laws of physics
and chemistry.
Irreducibility must not be identified with the mere fact that the
joining of parts
may produce features which are not observed in the separate parts. The sun is
a sphere, and its parts are not spheres, nor does the law of gravitation speak
of spheres; but mutual gravitational interaction causes the parts of the sun to
form a sphere. Such cases of wholism are common in physics and chemistry. They
are often said to represent a transition to living things, but this is not the
case, for they are reducible to the laws of inanimate matter, while
living things
are not.
But there does exist a rather different continuity between life and inanimate
nature. For the beginnings of life do not sharply differ from their
purely physicalchemical
antecedents. One can reconcile this continuity with the
irreducibility of living
things by recalling the analogous case of inanimate artifacts. Take
the irreducibility
of machines; no animal can produce a machine, but some animals can
make primitive
tools, and their use of these tools may be hardly distinguishable from the mere
use of the animal's limbs. Or take
a set of sounds conveying information; the set of sounds can be so obscured by
noise that its presence is no longer clearly identifiable. We can
say, then, that
the control exercised by the boundary conditions of a system can be
reduced gradually
to a vanishing point. The fact that the effect of a higher principle
over a system
under dual control can have any value down to zero may allow us also
to conceive
of the continuous emergence of irreducible principles within the
origin of life.
We Can Now Recognize Additional Irreducible Principles
The irreducibility of machines and printed communications teaches us,
also, that
the control of a system by irreducible boundary conditions does not interfere
with the laws of physics and chemistry. A system under dual control relies, in
fact, for the operations of its higher principle, on the working of principles
of a lower level, such as the laws of physics and chemistry. Irreducible higher
principles are additional to the laws of physics and chemistry. The principles
of mechanical engineering and of communication of information, and the equivalent
biological principles, are all additional to the laws of physics and
chemistry.
But to assign the rise of such additional controlling principles to a selective
process of evolution leaves serious difficulties. The production of
boundary conditions
in the growing fetus by transmitting to it the information contained
in DNA presents
a problem. Growth of a blueprint into the complex machinery that it describes
seems to require a system of causes not specifiable in terms of
physics and chemistry,
such causes being additional both to the boundary conditions of DNA and to the
morphological structure brought about by DNA.
This missing principle which builds a bodily structure on the lines
of an instruction
given by DNA may be exemplified by the far-reaching regenerative powers of the
embryonic sea urchin, discovered by Driesch, and by Paul Weiss's discovery that
completely dispersed embryonic cells will grow, when lumped together,
into a fragment
of the organ from which they were isolated.3 We see an integrative
power at work
here, characterized by Spemann and by Paul Weiss as a "field"4, which
guides the growth
of embryonic fragments to form the morphological features to which
they embryologically
belong. These guides of morphogenesis are given a formal expression
in Waddington's
"epigenetic landscapes"',. They say graphically that the
growth of the
embryo is controlled by the gradient of potential shapes, much as the motion of
a heavy body is controlled by the gradient of potential energy.
Consciousness is a principle that fundamentally transcends not only physics and chemistry but also the mechanistic principles of living things.
Remember how Driesch and his supporters fought for recognition that
life transcends
physics and chemistry, by arguing that the powers of regeneration in
the sea urchin
embryo were not explicable by a machinelike structure, and how the controversy
has continued, along similar lines, between those who insisted that regulative
("equipntential" or "organismic") integration was
irreducible
to any machinelike mechanism and was therefore irreducible also to the laws of
inanimate nature. Now if, as I claim, machines and mechanical
processes in living
beings are themselves irreducible to physics and chemistry, the
situation is changed.
If mechanistic and organismic explanations are both equally
irreducible to physics
and chemistry, the recognition of organismic processes no longer
hears the burden
of standing alone as evidence for the irreducibility of living things. Once the
"field"-like powers guiding regeneration and morphogcnesis
can be recognized
without involving this major issue, I think the evidence for them will be found
to be convincing.
There is evidence of irreducible principles, additional to those of
morphological
mechanisms, in the sentience that we ourselves experience and that we observe
indirectly in higher animals. Most biologists set aside these matters
as unprofitable
considerations. But again, once it is recognized, on other grounds
that life transcends physics and chemistry, there is no reason for suspending
recognition of the obvious fact that consciousness is a principle
that fundamentally
transcends not only physics and chemistry but also the mechanistic principles
of living beings.
Biological Hierarchies Consist of a Series of Boundary Conditions
The theory of boundary conditions recognizes the higher levels of
life as forming
a hierarchy, each level of which relies for its workings on the principles of
the levels below it, even while it itself is irreducible to these
lower principles.
I shall illustrate the structure of such a hierarchy by showing the
way five levels
make up a spoken literary composition.
The lowest level is the production of a voice; the second, the
utterance of words;
the third, the joining of words to make sentences; the fourth, the working of
sentences into a style; the fifth and highest, the composition of the text.
The principles of each level operate under the control of the
next-higher level.
The voice you produce is shaped into words by a vocabulary; a given vocabulary
is shaped into sentences in accordance with a grammar; and the
sentences are fitted
into a style, which in turn is made to convey the ideas of the
composition. Thus
each level is subject to dual control: (i) control in accordance with the laws
that apply to its elements in themselves, and (ii) control in accordance with
the laws of the powers that control the comprehensive entity formed
by these elements.
Such multiple control is made' possible by the fact that the
principles governing
the isolated particulars of a lower level leave indeterminate conditions to be
controlled by a higher principle. Voice production leaves largely
open the combination
of sounds into words, which is controlled by a vocabulary. Next, a vocabulary
leaves largely open the combination of words to form sentences, which
is controlled
by grammar, and so on. Consequently, the operations of a higher level cannot be
accounted for by the laws governing its particulars on the next-lower' level.
You cannot derive a vocabulary from phonetics; you cannot derive grammar from
a vocabulary; a correct use of
grammar does not account for good style; and a good style does not supply the
content of a piece of prose.
Living beings comprise a whole sequence of levels forming such a
hierarchy. Processes
at the lower levels are caused by the forces of inanimate nature, and
the higher
levels control, throughout, the boundary conditions left open by the
laws of inanimate
nature. The lowest functions of life are those called vegetative. These vegetative
functions, sustaining life at its lowest level, leave open-both in plants and
in animals-the higher functions of growth and in animals also leave
open the operations
of muscular actions. Next, in turn, the principles governing muscular actions
in animals leave open the integration of such actions to innate
patterns of behavior;
and, again, such patterns are open in their turn to be shaped by intelligence,
while intelligence itself can be made to serve in man the still
higher principles
of a responsible choice.
Each level relies for its operations on all the levels below it. Each reduces
the scope of the one immediately below it by imposing on it a
boundary that harnesses
it to the service of the nexthigher level, and this control is
transmitted stage
by stage, down to the basic inanimate level.
The principles additional to the domain of inanimate nature are the product of
an evolution the most primitive stages of which show only vegetative functions.
This evolutionary progression is usually described as an increasing complexity
and increasing capacity for keeping the state of the body independent
of its surroundings.
But if we accept, as I do, the view that living beings form a
hierarchy in which
each higher level represents a distinctive principle that harnesses the level
below it (while being itself irreducible to its lower principles),
then the evolutionary
sequence gains a new and deeper significance. We can recognize then a strictly
defined progression, rising from the inanimate level to ever higher additional
principles of life.
This is not to say that the higher levels of life are altogether
absent in earlier
stages of evolution. They may be present in traces long before they
become prominent.
Evolution may be seen, then, as a progressive intensification of the
higher principles
of
life. This is what we witness in the development of the embryo and of
the growing
childprocesses akin to evolution.
But this hierarchy of principles raises once more a serious
difficulty. It seems
impossible to imagine that the sequence of higher principles,
transcending further
at each stage the laws of inanimate nature, is incipiently present in DNA and
ready to be transmitted by it to the offspring. The conception of a blueprint
fails to account for the transmission of faculties, like consciousness, which
no mechanical device can possess. It is as if the faculty of vision were to be
made intelligible to a person born blind by a chapter on sense physiology. It
appears, then, that DNA evokes the ontogeoesis of higher levels,
rather than determining
these levels. And it would follow that the emergence of the kind of hierarchy
I have defined here can be only evoked, and not determined, by atomic
or molecular
accidents. However, this question cannot be argued here.
Understanding a Hierarchy Needs "from-at" Conceptions
I said above that the transcendence of atomism by mechanism is reflected in the
fact that the presence of a mechanism is not revealed by its physical-chemical
topography. We can say the same thing of all higher levels: their description
in terms of any lower level does not tell us of their presence. We
can generally
descend to the components of a lower level by analyzing a higher level, but the
opposite process involves an integration of the principles of the lower level,
and this integration may be beyond our powers.
In practice this difficulty may be avoided. To take
a common example, suppose that we have repeated a particular word,
closely attending
to the sound we are making, until these sounds have lost their meaning for us;
we can recover this meaning promptly by evoking the context in which the word
is commonly used. Consecutive acts of analyzing and integrating are
in fact generally
used for deepening our understanding of complex entities comprising two or more
levels.
Yet the strictly logical difference between two consecutive levels remains. You
can look at a text in a language you do not understand and see the letters that
form it without being aware of their meaning, but you cannot read a
text without
seeing the letters that convey its meaning. This shows us two
different and mutually
exclusive ways of being aware of the text. When we look at words without
understanding
them we are focusing our attention on them, whereas, when we read the
words, our
attention is directed to their meaning as part of a language. We are aware then
of the words only subsidiarily, as we attend to their meaning. So in the first
case we are looking at the words, while in the second we are looking from them
at their meaning: the reader of a text has a from-at knowledge of the
words' meaning,
while he has only a from awareness of the words he is reading. Should
he be able
to shift his attention fully toward the words, these would lose their
linguistic
meaning for him.
Thus a boundary condition which harnesses the principles of a lower
level in the
service of a new, higher level establishes a semantic relation between the two
levels. The higher comprehends the workings of the lower and thus
forms the meaning
of the lower.
And as we ascend a hierarchy of boundaries, we reach to ever higher levels of
meaning. Our understanding of the whole hierarchic edifice keeps deepening as
we move upward from stage to stage.
The Sequence of Boundaries Bears on Our Scientific Outlook
The recognition of a whole sequence of irreducible principles
transforms the logical
steps for understanding the universe of living beings. The idea, which comes to
us from Galileo and Gassendi, that all manner of things must
ultimately be understood
in terms of matter in motion is refuted. The spectacle of physical
Though rooted in the body, the mind is free in its actions-exactly as our common sense knows it to be free.
matter forming the basic tangible ground of the universe is found to be almost
empty of meaning. The universal topography of atomic particles (with
their velocities
and forces) which, according to Laplace, offers us a universal knowledge of all
things, is seen to contain hardly any knowledge that is of interest. The claims
made, following the discovery of DNA, to the effect that all study of
life could
be reduced eventually to molecular biology, have shown once more that
the Laplacean
idea of universal knowledge is still the theoretical ideal of the
natural sciences;
current opposition to these declarations has often seemed to confirm
this ideal,
by defending the study
of the whole organism as being only a temporary approach. But now the analysis
of the hierarchy of living things shows that to reduce this hierarchy
to ultimate
particulars is to wipe out our very sight of it. Such analysis proves
this ideal
to be both false and destructive.
Each separate level of existence is of course interesting in itself and can be
studied in itself. Phenomenology has taught this, by showing bow to save higher,
less tangible levels of experience by not trying to interpret them in terms of
the more tangible things in which their existence is rooted. This
method was intended
to prevent the reduction of man's mental existence to mechanical
structures. The
results of the method were abundant and are still flowing, but
phenomenology left
the ideal of exact science untouched and thus failed to secure the exclusion of
its claims. Thus, phenomenological studies remained suspended over an abyss of
reductionism. Moreover, the relation of the higher principles to the workings
of the lowest levels in which they are rooted was lost from sight
altogether.
I have mentioned how a hierarchy controlled by a series of boundary principles
should be studied. When examining any higher level, we must remain subsidiarily
aware of its grounds in lower levels and, turning our attention to the latter,
we must continue to see them as bearing on the levels above them.
Such alternation
of detailing and integrating admittedly leaves open many dangers. Detailing may
lead to pedantic excesses, while too-broad integrations may present us with a
meandering impressionism. But the principle of stratified relations does offer
at least a rational framework for an inquiry into living things
and the products of human thought.
I have said that the analytic descent from higher levels to their subsidiaries
is usually feasible to some degree, while the integration of items of a lower
level so as to predict their possible meaning in a higher context may be beyond
the range of our integrative powers. I may add now that the same things may be
seen to have a joint meaning when viewed from one point, but to lack
this connection
when seen from another point. From an airplane we can see the traces
of prehistoric
sites which, over the centuries, have been unnoticed by people
walking over them;
indeed, once he has landed, the pilot himself may no longer see these
traces.
The relation of mind to body has a similar structure. The mind-body
problem arises
from the disparity between the experience of a person observing an
external object-for
example, a cat and a neurophsiologist observing the bodily mechanism by means of
which the person sees the cat. The difference arises from the fact
that the person
observing the cat has a from-knowledge of the bodily responses evoked
by the light
in his sensory organs, and this from-knowledge integrates the joint meaning of
these responses to form the sight of the cat, whereas the
neurophysiologist, looking
at these responses from outside, has only an atknowledge of them,
which, as such,
is not integrated to form the sight of the cat. This is the same duality
that exists between the airman and the pedestrian in interpreting the
same traces,
and the same that exists between a person who, when reading a written sentence,
sees its meaning and another person who, being ignorant of the language, sees
only the writing.
Mechanisms, whether man-made or morphological, are boundary
conditions harnessing
the laws of inanimate nature, being themselves irreducible
to those laws.
Awareness of mind and body confront us, therefore, with two different things.
The mind harnesses neurophysiologieal mechanisms and is not determined by them.
Owing to the existence of two kinds of awareness-the focal and the
subsidiary-we
can now distinguish sharply between the mind as a "from-at"
experience
and the subsidiaries of this experience, seen focally as a bodily mechanism. We
can see then that, though rooted in the body, the mind is free in its
actions-exactly
as our common sense knows it to he free.
The mind itself includes an ascending sequence of principles. Its
appetitive and
intellectual workings
are transcended by principles of responsibilit. Thus the growth of man to his
highest levels is seen' to take place along a sequence of rising
principles. And
we see this evolutionary hierarchy built as a sequence of boundaries,
each opening
the way to higher achievements by harnessing the strata below them,
to which they
themselves are not reducible. These boundaries control a rising
series of relations
which we can understand only by being aware of their constituent
parts subsidiarily,
as bearing on the upper level which they serve.
The recognition of certain basic impossibilities has laid the
foundations of some
major principles of physics and chemistry; similarly, recognition of
the impossibility
of understanding living things in terms of physics and chemistry, far
from setting
limits to our understanding of life, will guide it in the right direction. And
even if the demonstration of this impossibility should prove of no
great advantage
in the pursuit of discovery, such a demonstration would help to draw
a truer image
of life and man than that given us by the present basic concepts of
biology.
Summary
Mechanisms, whether man-made or morphological, are boundary
conditions harnessing
the laws of in
animate nature, being themselves irreducible to those laws. The
pattern of organic
bases in DNA which functions as a genetic code is a boundary
condition irreducible
to physics and chemistry. Further controlling principles of life may
be represented
as a hierarchy of boundary conditions extending, in the case of man,
to consciousness
and responsibility.
REFERENCES AND NOTES
1More precisely, each item consists of one out of four alternatives consisting
in two positions of two different compound organic bases.
2The blueprint carried by the DNA molecule of a particular zygote
also prescribes
individual features of this organism, which contribute to the sources
of selective
evolution, but I shall set these features aside here.
3See P. Weiss, Proc. Nat. Acad. Sci. U.s. 42, 819 (1956).
4The 'field" concept was first used by Spemann (1921) in
describing the organizer;
Paul Weiss (1923) introduced it for the study of regeneration and extended it
1 1926) to include ontogeny. See P. Weiss, Principles of Development (Halt, New
York, 1939), p. 290.
5See, for example, C. H. Waddingtun, The Strategy of the Genes (Allen
& Unwin,
London, 1957), particularly the graphic explanation of "genetic
assimilation"
on page 167.
6See, for example, M. Palanyi, Amer. Psychologist 23 (Jan. 1968) or
---,
The Tacit Dimension (Doubleday, New York, 1967).
I.
DO LIFE PROCESSES TRANSCEND PHYSICS AND CHEMISTRY?
Richard H. Bube
Department of Materials Science
Stanford University, Stanford,
California 94305
From: JASA 22 (December 1970): 125-127.
This is the title of one of the general symposia of the AAAS meeting
on December
30, 1967, the transcript of which was published in Zygon 3, 442
(1968). Participants
in the symposium were Gerald Holton, Chairman, Professor of Physics at Harvard
University; Michael Polanyi, Professor of Physical Chemistry at
Victoria University
at Manchester, England, from 1933 to 1948, and then Professor of
Social Sciences;
Ernest Nagel, University Professor at Columbia University; John R.
Platt, Research
Biophysicist and Associate Director of the Mental Health Research Institute of
the University of Michigan; and Barry Commoner, Chairman of the
Department of
Botany and Director of the Center for the Biology of Natural Systems
at Washington
University in St. Louis. This distinguished panel addressed itself to
the question
of the title. In view of the article by Dr. Polanyi published in this issue of
the Journal ASA, we shall not repeat his perspective here, but will concentrate
instead on the contributions of the other members of the panel.
Nagel argued principally that the question could not be decisively
answered, maintaining
that the impossibility of reducing biology to physics and chemistry
was a position
that could not be conclusively established. In order to answer the
question posed
in the title, it is necessary to know what theory of physics and chemistry is
in mind as the basis of the explanation. Although it may not be
possible to reduce
biological phenomena to presently known theories of physics and chemistry, who
is to say what the future might bring? The issue is an empirical one, not one
to be solved by abstract philosophical cogitation.
Nagel also emphasized two other points of relevance. (1) The observation that
terms exist in laws at a higher level that do not exist in laws at a lower
level cannot be used as conclusive evidence that the laws at a higher
level cannot
he explained by laws at a lower one. (2) Two questions must be kept separate:
whether it is possible to give a physicochemical explanation of biological laws
as they relate to biological organisms at the present, and whether it
is possible
to give a physicochemical explanation of the laws involved in the historical or
evolutionary development of biological organisms. Nagel feels that it is quite
possible that the answer is yes to the first of these questions, and no to the
second.
Platt answered an emphatic, "Yes," to the question of the title. His
reasons fall into three categories. (1) Ordinary analysis from the
"objective"
point of view. Emergent properties"systems
properties"characterize biological
systems with increasing size and complexity, and systems properties
are not easily
predictable from the properties of the subsystems. Can one predict
the properties
of gravity from atomic and nuclear physics? the properties of a
traffic jam from
those of individual cars? the significance of the sign,
"Joe's Bar and Grill", from a knowledge of gas-discharges?
the properties
of 1014 synapses in the human brain from the properties of the
approximately 103
properties of physics, the 10 questions treated by chemistry, or the 10 bits of
information in the DNA chain in biology? (2) Experimental and logical
predictability. There is one kind of practical indeterminacy that
derives simply
from the fantastic complexity of the human brain. There is a second
kind of indeterminacy:
the logical invalidity of self-prediction, i.e., scientific predictability in
the realm of interpersonal human actions affects the nature of the action, as
discussed by D. M. MacKay. (3) The role of subjectivity. The world is divided
into two parts; yet these two parts are inseparable. There is the
world of physics,
the external half-world in which spoons are picked up and dropped again. There
is also the world of cybernetics, the internal half-world in which the choice
is made to pick up a spoon and to drop it. "The result is that the world
of physics and chemistry is only half a world. It's the world 'out there.' It
is
the world without values, without love, without death, without
vomiting."
Commoner argued that the work of Koniherg, Lederberg and Crick
establishes clearly
on empirical grounds that life transcends chemistry. He restricted himself to
a particular aspect of biology, namely the property of life that
involves inheritance,
self-duplication, replication. In the "central dogma", as set forth
by Crick, it is proposed that DNA determines RNA, RNA determines
protein, protein
determines inheritance, and the reverse processes are forbidden.
Commoner interprets
recent experiments that show that when DNA is synthesized by a
protein (DNA polymerase),
the biochemical specificity of the polymerase influences the
nucleotide sequence
of the DNA, as contradicting the "central dogma" because it
shows that
the source of genetic specificity (protein) is derived partially from DNA, and
that the specificity of DNA is partially derived from protein. Thus he argues
that "it is now clear that the origin of genetic specificity in
self-duplication
is not monomolecular.
It does not come from DNA; it comes from the interaction of an array
of molecules."
He argues further that the work of Nierenberg has shown that the code
which translates
the DNA nucleotide sequence into the amino acid sequence in proteins
is not universal
(empirically, seven out of twenty cases were not universal). Finally he argues
that not even chemistry has been reduced to physics since it is not possible to
use quantum mechanics to predict otherwise unknown molecular structures.
A final quote from Commoner may be appropriate to conclude this summary:
I think the trouble with molecular biology is that it's a brilliant attempt to reduce biology to old-fashioned and outmoded physics. Atomism works beautifully in a cer tain realm of physics-in atomic physics It may
well turn out that atomic physics is a special case in which atomism works and that in the rest of the universe we are confronted with a totally new problem.
Cohn Duricz
Reprinted from the Christian Graduate 22, No. 3, 24 (1969)
From: JASA 22 (December 1970): 128-131.
II
'William Paley, the eighteenth-century Christian apologist,
pictured God
as making the universe like a watch which He wound up, left to tick,
and occasionally
repaired. For those modern Christians who are ashamed of Paley, it will come as
a shock that a kind of teleological argument from mechanical design
is seriously
being reintroduced by the distinguished nonChristian scientist and pilosopher,
Dr. Michael Polanyi. This is all the more interesting because, instead of God
being the designer, the design is attributed to an evolutionary process which
is not personified, and which cannot be described in the scientific language of
physics and chemistry.
Considering the universe for a moment as a machine, let us look at
Polanyi's argument.
Almost all scientists today believe, of course, that, in the words of Polanyi,
"so far as life can be represented as a mechanism, it is explained by the
laws of inanimate nature". Dr. Polanyi's position is
antithetical, and this
is his revolution: "I differ ... most from biologists, by holding that no
mechanism-be it a machine or a machine-like feature of an
organism-can be represented
in terms of physics and chemistry." Even more strongly than
this, he expresses
incredulity that
for 300 years writers who contested the possibility of explaining life by physics and chemistry argued by affirming that living things are not, or not wholly, machinelike, instead of pointing not that the mere existence of machinelike functions in living beings proves that life cannot be explained in terms of physics and
chemistry.
The reasons he gives for his hypothesis fall into three major points.
1. His first reason is that machines are not reducible
to a description in terms of physico-chemical laws. This is because
they are defined
by the distinctive functions which the mind of man has imposed upon
them; machines
are shaped and designed for a special purpose. A 'washing-machine' is defined
by its function of 'washing clothes', and the clothes-washing function is what
moulds it to its typical recognizable shape.
An illustration reminiscent of Paley that Polanyi gives in several
essay-articles
is the watch: a physical and chemical molecular topography of his watch would
not give enough information to tell you 'what' it is. In contrast, a
child's description-the
thingamajig you have on your wrist to tell the time with-gives this
information.
There is a related problem when more obvious means of conveying information are
considered. A physical chemical topography of the page you are reading at this
moment would say nothing of its word content, or the total meaning of
those words.
2. It will prove easier to understand his second
point if it is realized that all machines as a whole make
up a boundary condition (a term borrowed from physics). What Dr. Polanyi calls
a 'boundary condition' may be taken to mean any form which is
distinct in quality
from all other forms, and which can have a diversity of possible contents. The
sonnet-form in poetry would be such a 'boundary condition'; so would
the medieval
Christian and early modern scientific concept of the universe, and so would
be
such a thing
as speech. (The latter is one of Polanyi's own examples.) But the
'boundary condition'
also necessarily includes the function defining a machine which we discussed in
the first point. Thus we may say-even though the more important constituent of
the two is not made explicit-that it is the structure or form of the machine,
with its function, which makes up its boundary condition.
In all machines, the boundary conditions exert a control or organization over
the materials which compose them, even though the material nevertheless works
autonomously according to physico-chemical laws. Polanyi concludes
therefore that
any mechanism is clearly under a hierarchical dual control. The 'upper level'
is under the control of a particular boundary condition-constituted
by the distinctive
machine-structure plus its related function-which harnesses the baser
'lower level'
controlled according to physical and chemical laws. If, for example, a car is
smashed into a cube in a junk-yard, the 'lower level' laws of physics
and chemistry
continue to work just as inexorably in the cube as they did in the car when it
was speeding down the freeway.
By this principle of boundary condition, Polanyi says that it follows
that machine-like
structures of living beings appear likewise to be irreducible to
terms of physics
and chemistry. A biological organism has the two aspects of a
boundary condition:
its organs are defined by their vital functions (for example, the
digestive function
of the stomach), and its total shape or 'morphology', with the shapes
of its parts,
enable it to be recognized; both aspects together tell 'what'
it is. The former aspect partially parallels the function of a
machine. The more
important formal or morphological aspect of the biological organism parallels
the structure of the machine. Without these irreducible plant and
animal morphologies
or forms, of course, biological science would not exist. It
categorizes the observed
in plants and animals. On the impossibility of biology ever being a molecular
science, Polanyi says,
Even supposing we did produce a mathematical expression for the shape of one living specimen, including all its anatomy at one particular moment, the formula would not cover its changes due to growth and decline and it would of course fail even more widely to cover the variety of specimens belonging to one species.
Not only is a comprehensive species a boundary condition, but also the unity of
identity of a growing plant or animal from seed to adult.
3. The third step in Polanyi's argument is this: the code or 'template'-as Prof.
J. D. Bernal calls it on the helix or coil of the DNA molecule is similarly not
describable in terms of physics and chemistry. James Watson and Sir
Francis Crick,
and the majority of biologists, believe that DNA templates determine the growth
and morphologies (forms) of all the animate world, making life
"one biochemically
interconnected unity every element of which, down to the smallest
virus, operates
its synthesis by this . . . molecular mechanism" of DNA (Bensal, Science
in History, p. 198). This seems to prove the contrary to Polanyi's
view; it seems
to make 'life' determinable by the inanimate laws of physics and chemistry.
But, argues Polanyi, DNA is in itself a boundary condition, and as such cannot
be reduced to physicochemical laws. In the first place, the DNA is defined by
its genetic function, the biological equivalent to a machine's reason for being
constructed. In the second place, and more important, it bears a
quantity of information
that "determines the genetic development of an organism".
This is because,
by self-duplication, the information-content of the DNA mechanism
induces in posterity
"an equivalent amount of organic differentation". In short,
it in reality
determines the plan or animal morphology, or structure.
This 'shaping' aspect of DNA has two implications: (i) as an
information-conveyor,
the DNA code, like a page of print, defies reduction to physics and chemistry;
(ii) as DNA hears a pattern or blue-print 'informed' with the shape
of the potential
new organism, the pattern must be regarded as just as much a morphological (or
structural) feature of that organism as that shape is. As a
morphological feature
of an organism, the DNA pattern cannot therefore he reduced to physico-chemical
laws. This means simply that DNA in its vital function of shaping life fulfills
the requisites of a boundary condition, and as such controls or organizes from
a 'higher level' the various chemicals which materially make up the DNA coil;
constituents which, as the 'lower level', also work autonomously according to
the laws of physics and chemistry. This 'upper level' boundary condition says
Poaoyi "brings the vital shaping of offspring by DNA into consonance with
the shaping of a machine by the engineer".
Cosmic Implications
Moving from the micro level to the cosmic, Polanyi does not regard the universe
to be under a boundary condition in its totality. He believes it to
he essentially
disorganized; that is, in a probable state according to
the Second Law of Thermodynamics. This does not relieve him of the
designer-difficulty,
however. His belief that the animate portion of nature and manmade machines are
controlled by boundary conditions, leaves open the question of
morphogeoesis (the
emergence of form from chaos) and the beginnings of consciousness
just as urgently
as if the universe is regarded as a mechanism. More naively, the question could
he formulated, 'Who or what is the designer of the mechanisms of
animate nature?'
It is significant that Dr. Polanyi feels the current theories of evolution to
he quite inadequate to these problems. This is because, in describing
biological
organisms, the biologist assumes their shapes (morphologies; boundary
conditions)
to he valid scientific data. Yet the biologist, then attributes morphogenesis
and the arrival of consciousness to natural selection. Polanyi, in
terms too technical
to repeat here, argues clearly that such a probable or predictable selection as
natural selection in such an arrangement as the four mobile chemical
substituents
on the DNA coil would allow no information-content, content which
obviously must
be there if DNA carries the blueprints for all living organisms.
Information requires
an improbable or unpredictable organization by an imposed boundary condition.
A partial but good analogy is the way wordsymbols have been arranged
in this article
by my mind. The words are not in an alphabetical sequence, or in any
other orderly
predictable sequences based on such factors as the numbers of letters
or syllables
(e.g., ones before twos, twos before threes, etc.). Rather they serve me in my
communication-attempt, and are selected and organized from my vocabulary with
this function in view, although of course some modifications of style
and grammar
have taken place.
At this exciting point in his theory, Dr. Polanyi
makes a profound optimistic jump in his reasoning. Mechanical control
in animate
nature, he points out, is not determinable from the 'lower level' of
physicochemical
laws. Furthermore, there is a hierarchy of mechanisms with man at the top. Man
alone has sufficient consciousness to impose boundary conditions
without a prewritten
blueprint such as DNA; man alone can make blueprints. If biological structures
are irreducible to physico-chemical laws, and likewise such things as man-made
machines and communication symbol-systems, then why cannot man's consciousness
be accepted as irreducible? Such an irreducibility frees a man from
the shackles
of believing himself to he a machine whose blueprint is completely prewritten,
a belief strongly adhered to by Sir Francis Crick or Gilbert Ryle,
for example.
Dr. Polanyi's optimism concerning the reality of consciousness is a
logical jump
because he at present has no basis for it:
We need a theory of knowledge which shows tip the fallacy of a positivistic scepticism and authorises our knowledge of entities governed by higher principles (boundary conditions). Any higher principle can be
known only by dwelling in the particulars governed by it. Any attempt to observe a higher level of existence by a scrutiny of its several particulars must fail.
To 'authorise' the higher levels we observe in animate nature, and sense in our
own consciousness, a designer is necessary, a designer who has some
manlike qualities
(e.g., the ability to create blueprints for mechanisms). This
designer must also
he big enough, at least, to control and organize the vastness of the apparent
hierarchy of animate nature. Against bigness such as this, the nations are as
a drop in a bucket.
Sources for Polanyi
'Life Transcending Physics and Chemistry' (Chemical and Engineering News, August
21, 1967.)
'On the Modern Mind' (Encounter, May 1965). 'The Structure of
Consciousness' (Brain,
Part IV, 1966).
'Life's Irreducible Structure' (Science, Vol. 160, June 21, 1968).