I have to admit it's getting better
A little better all the time
(It couldn't get any worse)1
Is
Thomas Kuhn's theory of Scientific Revolutions correct? Is the
progress of science a gradual and additive enterprise? Or is it a
series of extraordinary breakthroughs completely different from the
“normal science” in between them? Answering this question
in the negative is problematic. Although Kuhn's theory is intended to
apply only to the sciences, one can draw parallels to other areas of
human intellectual development. Anyone who would claim that
intellectual development is a fundamentally additive process cannot,
therefore, agree or disagree with Kuhn completely. One can imagine a
conversation between intellectual historians:
A: Thomas Kuhn is wrong. Scientific Knowledge is additive.
B: All right then, what did he add?
The most fundamentally important addition Kuhn made was the emphasis he
placed upon
social aspects in scientific behavior. Scientific
paradigms are not ethereal forms or mechanistic rules of conduct, but
shared theories, rules, and values held by communities of individual
scientists. Kuhn's view of scientific progress turns our attention to
its
human nature. And with
our attention thus turned, we begin to see the uncertainty of the
enterprise – the glorious mistakes, jealous rivalries,
neurosis, and pure genius speculation. Science cannot be viewed as a
sort of computer or pocket watch, wound up in the Renaissance and
moving steadily forward since then. At the same time, Kuhn's
observations and theories are limited, and do not seem to accurately
describe the progression of all of the sciences. On pages 171-2 of
The Structure of Scientific Revolutions, Kuhn explicitly
endorses an analogous reading of his work, comparing scientific
“progress” with biological “progress”, almost
going so far as to suggest the scientific process as being Darwinian.
Kuhn's mistake is that
he did not go far enough. The relationship is
not analogous – human intellectual progress, by virtue of it
being done by humans, is biological in nature. Science is an extended
phenotype of the human species. In one sense, in relationship to “the
universe” or “being” or whatever else you may set
up to be an objective observer,
science has no purpose, no
progression beyond being an amusing diversion that we little
ape-creatures indulge in. But from a human perspective, science has a
progressive character – and the result is our greater ability
to explain and manipulate the world around us.
I don't trust Paradigms, they're shifty.
Kuhn's
The Structure of Scientific Paradigms provides a description
of science sharply at odds with previous notions regarding historical
progress, but that was over forty years ago. Rather than being the
daring innovation it once was, Kuhn's theories are now the closest
thing to conventional wisdom in studies of the History of Science,
and have been broadly applied to other disciplines. Our place, in the
first decade of the twenty-first century, cannot be to resist his
arguments, but to go beyond them.
Kuhn
describes previous theories of scientific development as gradual and
iterative – scientists proposing hypothesis based upon
observational data, building experiments to test these hypothesis,
discarding bad ideas, constructing theories out of good ideas, and
then using these theories to propose new hypothesis. Lather, rinse,
repeat.
Kuhn partially agrees with this conception of science, calling it
“normal science” working within an established
“scientific paradigm”. For Kuhn, normal science is the
act of solving puzzles, within an established framework of scientific
thought. For example, the Copernican revolution established that the
planets all revolved around the sun in uniform motion. This paradigm
of thought was accepted (after much initial resistance) because it
accurately predicted the solar year better than previous geocentric
models. But the Copernican Heliocentric model was slightly off when
predicting the orbits of the other planets around the sun, and it
thus fell to normal science to bring known facts about the places of
the planets in line with the Copernican theory. This is the normal
function of science – basic puzzle solving, with no
revolutionary changes. Indeed, normal science does not react well to
revolutionary ideas, and the scientific community usually greets them
with skepticism, if not outright hostility. Only after a significant
amount of time and energy has been spent on debate does a scientific
community accept a new paradigm en masse, with a theory going
from controversial to common wisdom in the blink of an eye.
The
previous example provides us with an immediate problem with Kuhn's
theory. What sort of science was Kepler performing when solving the
problem of planetary motion? Before he began his calculations, he had
accepted the Copernican paradigm, but most others in the scientific
community had not – it was his explanations of planetary motion
that led to the paradigm's acceptance. Kepler's astronomical
calculations certainly have the feel of normal science (from Kepler's
perspective) and the feel of a paradigm shift (to people after him).
Kuhn indicates that Kepler's discover of the planetary laws of motion
is archetypical of a paradigm shift. Scientists who were working
under the Copernican theory found anomalies that could not be
explained sufficiently with the existing rules, this provoked a
crisis of faith in the system, this crisis was solved with Kepler's
new theory, and the resolution was of a new Copernican-Kepler
paradigm that more accurately accounted for planetary motion. What is
this new paradigm? While one can interpret it as a refutation
of Copernicus, Kepler didn't seem to think so, viewing his theories
as a refinement of the Copernican Theory. Refining theories is
what normal science is supposed to do, according to Kuhn, and refined
theories are not supposed to create new paradigms. Except for when
they do.
Since
Kuhn took great care to analyze the sociological and psychological
backgrounds of scientists, I do not think he would begrudge me for
attempting to analyze his. He readily admitted that the examples
drawn from in the book were from a few limited fields of study that he
knew well. One might point out that in the history of science there
are two major scientific revolutions that follow Kuhn's description
of paradigm shifts almost exactly – those of Newton and
Einstein. It should not be ignored that Thomas Kuhn received his
undergraduate degree in physics. It is tempting to abandon these two
cases and concentrate on murkier scientific progress, but some
temptations are too strong not to resist.
Newton
appears to us, in historical hindsight, to be a towering figure of
genius, carving a new understanding of physics that stood
unchallenged for two centuries. At a time when his contemporaries
were engaged in explaining the actions of the universe only through
matter and motion, he had the vision (perhaps inspired by his intense
religiosity) to imagine forces, and the genius to create an entirely
new branch of mathematics to explain them. Newton himself (in a
letter to Robert Hooke) would disagree, “If I have been able to
see farther, it was only because I stood on the shoulders of giants.”
Comparing Newton's Principia Mathematica to Descartes'
Principles of Material Things (an example of the prevailing
mechanistic physics that existed before Newtonian physics) one is
struck not by their differences, but the degree to which they agree.
Newton's laws of motion are almost identical to Descartes'; there is
an argument to be made that Newton merely revised mechanistic physics
– a major revision, to be sure, but an additive one. Indeed,
one can also see hints of Aristotle's physics in Newton's – he
rehabilitated the lost idea that an object can have within it
qualities that compel motion with no other object acting upon it
(although Aristotle's causes of motion differ greatly from Newton's,
they share the idea of elementary forces compelling action). Perhaps
a measure of Newton's genius was that he still read Aristotle2.
In Einstein we have another example of what a
major paradigm shift looks like: a Swiss patent clerk working on the
outskirts of a community ensconced within a paradigm provided
revolutionary theories which were later proved to the satisfaction of
the scientific community to such a degree as to inaugurate a new way
of thinking about the universe itself. Indeed, his contemporaries
were fond of suggesting that Einstein's papers from his “Miracle
Year” advanced physics twenty years. And while Einstein was still busy
arguing over the details of his theories, younger physicists quickly
adopted them and created the study of quantum mechanics. Was it
normal science to solve the puzzles created by Einstein? Or was it
extraordinary science to create a new field of physics that even
Einstein resisted at first?
Kuhn's view of science is compelling when one looks at a broad outline of
the history of science, one can see a pattern of “normal
science” and “extraordinary science” operating in
tandem. When one looks closer, one sees more and more instances of
“extraordinary science” and paradigm shifts operating
within “normal science”. But we can also see long periods
of “normal science”, with no obvious “extraordinary
science” that nonetheless seem to have undergone a “paradigm
shift” over a period of decades or centuries. Even in the
archetypical scientific revolutions of Newton and Einstein, one gets
the feeling that the science they do is characterized not by its
nature, but by its speed. They are conspicuous because of the speed
with which they reached conclusions that had eluded others –
but the difference between “normal science” and
“extraordinary science” seems to be one of degree, not of
kind. And if Kuhn's view of science is supported most by the progress
of physics, it doesn't seem to correlate at all to the biological
sciences.
On the Origin of Theories
In
trying to correlate Kuhn's theory to modern biology, the only really
sensible analysis seems to be that before Darwin (and Wallace),
biology existed in a pre-paradigmatic state driven by theology,
metaphysics, vestigial Aristotelianism, and some stamp-collecting
(i.e. species classification). After Darwin and Wallace published
their theories, the scientific community fought it out, and
afterwards Darwinian Evolution has served as the primary paradigm for
all of the life sciences. Or in the words of Theodosius Dobzhansky,
“Nothing in biology makes sense, except in the light of
evolution.”
The
problem with this reading of the history of biology is that it
doesn't match up with historical reality – at least not in the
same way that the history of physics or chemistry does. While Darwin
and Wallace's theory maintained a place of prominence in biology
through the end of the nineteenth century and early part of the
twentieth century, it was not until R.A. Fisher synthesized natural
selection (in the 1930s) with Gregor Mendel's re-discovered early
genetic research that evolution became the dominant driving force in
biology, occupying a place easily identifiable as a scientific
paradigm. It was even later, with Gould and Eldredge's Punctuated
Equilibrium that paleontologists and geologists came on board (in
1972, over a century after Darwin published The Origin of
Species). This seems like an awfully long time for a paradigm to
take effect, and also – each of the above authors was certainly
writing within a Darwinian framework. There are problems on the other
side of the historical timeline, as Kuhn himself notes:
When Darwin first published his theory of evolution by
natural selection in 1859, what most bothered many professionals was
neither the notion of species change nor the possible descent of man
from apes. The evidence pointing to evolution, including the
evolution of man, had been accumulating for decades, and the idea of
evolution had been suggested and widely disseminated before. (Kuhn,
171)
Darwin's contribution was the idea of natural selection, unguided
evolution based upon a species ability to reproduce itself, rather
than some goal-oriented process. It was this idea that caused his
theory to be treated with skepticism by so many, but in many respects
it was just another stepping stone towards better understanding of
the biological process. If Darwin had presented his idea to a group
of cynical existentialists, they probably would have merely yawned.
This suggests a wholly different critique of Kuhn, his utter
disregard for the social and political climate within which science
must operate, but that is a subject for another paper.
The
early life sciences in the early nineteenth century explored the idea
of evolution (in particular, Lamarck proposed a differing sort of
evolution that relied upon vague ideas of teleological change), and the
diversification of species. Darwin and Wallace's work explained how
randomly mutating traits, inherited by successive generations that
managed to reproduce, resulted in diversification and
non-teleological evolution. Gregor Mendel explained how traits were
inherited, although not why. R. A. Fisher explained how genetics and
natural selection were partners and not competing theories. Watson
and Crick unraveled the double helix, explaining Mendel's why.
Eldredge and Gould explained how species were generally stable
populations, but that isolated populations could rapidly diversify,
thus solving a number of problems with the fossil record. Other
scientists have shown natural selection acting in the wild in a time
frame within a human lifespan, explored our own convoluted
evolutionary history (in and out of Africa again, etc.), decoded the
human genome, or done any number of things which both confirm
evolution and widen our awareness of its applications.
Any
number of these things could be described as a Kuhnian “paradigm
shift” in that they broaden the understanding of the scientific
community, solve certain anomalies, and provide more puzzles for
future research. But none of them contradicted the fundamentals of
Darwin's theory. And most of them prompted the same reaction that T.
H. Huxley had when he first read The Origin of Species, “How
extremely stupid not to have thought of that!” To be sure,
Kuhn's view of scientific behavior is not completely absent from the
history of biology. Any group of people has the capacity for
groupthink and most of us see what we expect to see when we examine
something. The above post-Darwinian biologists found Darwinian
answers to problems when they examined those problems through a
Darwinian mental lens. But their discoveries seem to be mostly
“normal science”, with only Fisher prompted by a
“crisis”. And yet if one is to say that there have been
any paradigm shifts in biology other than Darwin/Wallace, almost all
of the above would seem to fit. There is a better theory to explain
the history of biological development, actually all intellectual
development – and it is an extension of the modern
neo-Darwinian synthesis.
Extend the Phenotype, Meet the Meme.
In
normal discussions regarding genetics and biology, organisms are
described as having genotypes and phenotypes. Encoded within my DNA
is a string of chemicals that determine eye color; they manifest
themselves in a phenotype usually described as hazel. This is a
fairly easy concept to grasp, as an individual considers the lines of
code that determine (along with environment) most of our physical
characteristics. What is harder to grasp, but no less true, is that
our brain is a phenotype, and it contains within a chemical soup, a
morass of electrical impulses that we perceive as ideas. Our ability
to recognize things, to remember them, to critically evaluate them,
are all expressions of our DNA. The ideas we have are interactions
between our phenotypical reason and our environment.
Richard Dawkins put forth the proposition in The Selfish Gene that the
ideas humans have behave in a manner similar to genes, with regards
to their propagation throughout a population. He coined the term
“meme” to explain this phenomenon. Kuhn comes very close
to this idea when he describes science as analogous to Darwinian
evolution – in that it has no teleological goal. But memes,
unlike paradigms, are atomized (like genes). As we have seen,
scientific frameworks are not monolithic paradigms like Kuhn
describes, but rather convenient collections of ideas that look like
overarching structures. Rather than completely overturning Descartes,
Newton subtracted some bad ideas (plenum), added some good ideas
(gravity) and created a new collection of memes that were accepted by
his contemporaries and created a new framework for the physical
sciences. Anything that can be called science includes a crucial meme
first espoused in the western world (as far as we can tell) by Thales
of Miletus – that the world has natural explanations (this is a
crucial separation between the first philosophers and Greek
Mythology, as typified by Hesiod's Theogyny). Viewed in this
way, science can be seen to be additive, and yet include everyone
that we would like to consider a scientist, from Aristotle to
Hawking.
Kuhn’s
view of paradigms does seem to accurately reflect some scientific
behavior, and it is not difficult to see where “paradigms”
might fit into a memetic account of intellectual development –
just as genes express themselves in individuals, and memes express
themselves in complex ideas – individuals comprise species, and
complex sets of memetic propositions can be seen to comprise
paradigms. Kuhn describes a process of paradigmatic evolution
analogous to punctuated equilibrium in biological speciation. New
“species” of thought (what Kuhn calls paradigms) tend to
arise outside the stable centers of scientific thought, but then
propagate and replace their predecessors when they show they are able
to better survive in the scientific environment (solve more puzzles).
Science
can also be seen to be progressive, although Kuhn does not disagree
with the idea of a progressive science as much as some claim:
Later scientific theories are better than earlier ones
for solving puzzles in the often quite different environments to
which they are applied. That is not a relativist's position, and it
displays the sense in which I am a convinced believer in scientific
progress. (Kuhn, 206)
What
is key here is recognizing the environment of which Kuhn speaks. In
biological evolution, the environment is a host of factors for each
organism – every other organism in the shared environment, and
natural events. The environment within which scientific memes
propagate is somewhat dependent on the
natural world (insofar as the
business of science is in interacting with it) but the puzzles of
science are determined by humans – either colleagues sharing
memes or the public at large availing itself of scientific
discoveries. In this sense, scientific progress is not only possible,
but it is the most successful enterprise in human history.
1. Paul is dead.
2. Although
I don't have space for it in this paper, this idea can help resolve
the Aristotle dilemma that seems to be the “first mover”
for Kuhn's ideas. Namely, was Aristotle science? The earliest modern
scientists had battled Aristotle's science until the consensus was
that Aristotle was either “Not science” or “Bad
science”. Kuhn argues that he was “Different science”.
But given his continuing relevance (on rare actors such as Newton
and Heisenberg), I would argue that he was “Early science”
-- which is by definition (in a progressive view of history) both
different and largely wrong, but still occasionally relevant.