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During the
three hundred years in which the worldview of Newtonian physics
dominated the stage of Western thought, there were always voices
of dissent
In various fields of thought the reign of mechanism
was successively challenged by competing visionssuch as those
of vitalism, romanticism and idealismall more or less reflecting,
despite their other differences, what William James was to call
the tender-minded (as opposed to the tough-minded)
attitude toward the meaning of experience and reality.
After the
seventeenth century, however, these humanist alarms and excursions
proved more and more ineffectual in slowing the march of the mechanistic
philosophy toward the hubris of an all-embracing and all-sufficient
scientism... To oppose the prevailing cosmology was simply to be
against science; and to be against science was to stand
squarely in the path of truth and progress
But in the
twentieth century, for the first time, the image of the universe
as a great machine came under direct attack by science itselfand
not merely by a scattering of isolated researchers but by the full
mainstream of theoretical and experimental physics.
The Decline
of Mechanism
What has since come to be known as the revolution in modern science
reached its climax in the nineteen-twenties and thirties in the
field of quantum physics; but its preliminary engagements had been
fought and won half a century earlier. Even before that, the Laplacean
ideal of absolute certainty had been disturbed by the development
of thermodynamics, with its reliance upon probability. But the first
substantial indication of a crack in the mechanical model appeared
in the final quarter of the century in the wake of those exhaustive
investigations into electricity and magnetism through which, for
upwards of a hundred years, prodigies of scientific ingenuity had
been expended in a futile effort to fit these refractory phenomena
into the framework of classical mechanics. The great change
was brought about, as Einstein has noted, by Faraday,
Maxwell and Hertzas a matter of fact half unconsciously and
against their will.
In 1873,
proceeding from the ordained mechanical premises, Clerk Maxwell
ended up with a set of equations (the electromagnetic theory) which
clearly repudiated those premises and cast doubt upon the entire
foundation of Newtonian mechanics. Even then, many leading physicists
rejected Maxwells conclusions because they could not be rendered
visible and substantial in terms of a mechanical model. It was only
after decades had passed that the radical implications of Maxwells
theory were fully assimilated by his scientific colleagues, for
whom the ideal of mechanism had been too long an unquestioned article
of faith
The success
of the electromagnetic theory was significant not only as the first
breach in the great wall of mechanism, but also as a premonitory
clue to what might be termed the postmodern conception
of the nature of scientific knowledge. Previously it had been assumed
by the faithful that the descriptions of which science was capable
encompassed the whole of knowable realityin other words, that
what escaped the net of the scientific mechanist either did not
exist or was not worth knowing. Indeed, scientific explanation not
merely ordered and described the objects of its concern but penetrated
to their very essence
Through its
methods of mechanical reduction and mathematical reproduction, as
well as by its postulate of neutral objectivity, modern science
sought for (and was on the way to finding) not a limited aspect
of reality but the whole truth and nothing but the truth. It was
this passionate quest for certainty, this unqualified faith in the
power of Natural Magick to expose and explain the deepest
secrets of the universe, which principally characterized the creed
of scientism and constituted its peculiar hubris.
And it was
this fundamentalist faith which was profoundly shaken, if not yet
overturned, by the failure of the mechanistic assumptions to account
for the nature of electricity, and by the incontrovertible success
of Maxwells effort to comprehend the mystery in terms basically
alien to the Newtonian perspective. As a result of Maxwells
equations, as the mathematician Sullivan has put it, All that
we knew about electricity was the way it affected our measuring
instruments
The precise description of this behaviour gave
us the mathematical specification of electricity and this, in truth,
was all we knew about it. The significance of this departure
from the standard procedure and expectation of classical mechanics
dawned slowly upon the world of science.
Natural scientists
were understandably reluctant to modify a framework which had proved
so continuously fruitful both in theory and practice; and not only
natural scientists but social and political scientists as well were
unwillingand in substantial numbers remain unwilling todayto
abandon a worldview which, at whatever the price to human dignity
and moral freedom, had brought determinate order and the illusion
of certainty to the once-mysterious universe.
Writing more
than half a century after Maxwells discovery, Sullivan drew
the moral of his achievement: It is only now, in retrospect,
that we can see how significant a step this was
It has become
evident that, so far as the science of physics is concerned, we
do not require to know the entities we discuss, but only their mathematical
structure. And, in truth, that is all we do know. It is now realized
that this is all the scientific knowledge we have even of the familiar
Newtonian entities. Our persuasion that we knew them in some exceptionally
intimate manner was an illusion.
The
progress of science, declared Whitehead in 1925, has
now reached a turning point. The stable foundations of physics have
broken up
The old foundations of scientific thought are becoming
unintelligible. Time, space, matter, material, ether, electricity,
mechanism, organism, configuration, structure, pattern, function,
all require reinterpretation.
It was not
only that physicists no longer knew what they meant by mechanics;
in more and more corners of their field, they were ceasing to think
at all in mechanical terms
Our modern minds have, I
think, remarked Jeans, a bias towards mechanical interpretations.
Part may be due to our early scientific training; part perhaps to
our continually seeing everyday objects behaving in a mechanical
way, so that a mechanical explanation looks natural and is easily
comprehended.
After the full impact of relativity had been felt, however, little
was left of this ingenuous belief in the scientific image of objective
reality, as faithfully registered by the senses. It began to be
recognized that the familiar picture, far from being a genuine photographic
reproduction of an independent reality out there, was
rather more on the order of a painting: a subjective creation of
the mind, which could convey a likeness but could never
produce a replica
And Sir James
Jeans
felt safe in declaring: Today there is a wide
measure of agreement which on the physical side of science approaches
almost to unanimity, that the stream of knowledge is heading towards
a non-mechanical reality; the universe begins to look more like
a great thought than like a great machine
There is
a further consideration bearing on the uncertainty principle which
deserves comment. It is often asserted that the element of ambiguity
which quantum physics has exposed in the fundamental operations
of nature, whatever its significance may be within this miniature
world, does not affect our observation of events in the macroscopic
world of everyday affairs. The conventional procedures of classical
mechanics, in this view, remain as accurate as ever for large-scale
happenings in which vast numbers of particles are involved. In a
limited and strictly practical sense this supposition is perhaps
unobjectionable; but if it is taken to mean that the structure of
Newtonian law embracing the visible world has remained unaffected
by the quantum revolution, it is seriously misleading. For while
it is true that for ordinary purposes the traditional procedures
are still pragmatically validi.e., adequate for
the measurements which we normally undertakeit is no less
true that the principles which formerly supported them are in shambles.
The new and very different laws which have been discovered in the
realm of quanta do not stop at the atoms edge;
if they may be generally disregarded on the macrophysical level
it is not because this territory is beyond their jurisdiction but
only because our sensory and mechanical equipment is too gross to
detect their presence. The quanta are however there.
What is no
longer there is the mechanistic assumption of clockwork
certainty which underlay the Newtonian cosmology and was so aptly
embodied in Laplaces demon. Where once it could be assumed
as an article of faith that perfect precision and infallible prediction
were in principle within the power of scienceand, accordingly,
that any inexactness in our findings was only a temporary and technical
impedimenttoday it is all but universally acknowledged that
the data of classical physics are at best approximations (limiting
cases of the quantum theory) doomed forever to an irreducible
imprecision not merely in practice but in principle as well.
The difference
which this makes in the outlook of science, and perhaps not only
of science, is considerable. The dogmatic determinism of the scientific
mechanist was as rigorous as it as all-embracing; it countenanced
no loose talk of capriciousness or chance in any corner of the universe
Indeed, although
the principle of uncertainty has reference to very small particles
and events, it does not at all follow, as Bronowski has seen, that
these events are of small importance. They are just the sorts
of events which go on in the nerves and the brain and in the giant
molecules which determine the qualities we inherit. And sometimes
the odd small events add up to a fantastic large one. [Ed:
as in the mutations in the genetic code]
It may be
enough to underscore the broadest and most reliable inference for
the humane sciences which has thus far emerged from the physical
revolution of our century: that as the mechanistic viewpoint has
been found to be inadequate for the full comprehension of inorganic
matter and natural events, it is inadequate for the understanding
of human nature and human events; and, more specifically, that the
assumption of objective predeterminism upon which all consistent
causal analysis (with its corollaries of exact prediction and control)
must finally depend is, in simple fact, without confirmation in
the new physics of possibility.
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