Thomas Kuhn's book The Structure of Scientific Revolutions is one of the most
influential and controversial works of the 20th century. In the first episode of this
series on Kuhn's seminal work, we talked about the word paradigm which has
penetrated every layer of the culture all thanks to this work of Kuhn.
In this episode we are going to look the role of paradigms in the development of
science and we are going to talk about the eponymous structure of scientific
revolutions.
In the Kuhnian model of scientific history there are three modes that a scientific field
can be in: there's the pre-paradigm phase, the paradigm phase also known as normal
science and finally the revolutionary or extraordinary phase.
Kuhn calls the first stage of a science the pre-paradigm phase. During this phase, there
is no paradigm that has gained consensus in the field; there may be a number of
competing paradigms that vie for support but as of yet no single paradigm has united
the field under one banner and one research project.
Because of this, there is little progress made. Every scientist must start again at the
fundamentals - they must argue why they have chosen the paradigm they have
chosen. Kuhn illustrates this
by taking the development of the scientific field of study of light
called physical optics. He explains that before Newton's seminal work Optiks, there
were a number of competing paradigms: the Aristotelian, the Platonic and the
Epicurean each of which could explain some phenomena but none of which had
greater explanatory power than any of the others. He writes:
Being able to take no common body of belief for granted, each writer on
physical optics felt forced to build his field anew from its foundations. In
doing so, his choice of supporting observation and experiment was
relatively free, for there was no standard set of methods or of
phenomena that every optical writer felt forced to employ and explain.
Under these circumstances, the dialogue of the resulting books was often
directed as much to the members of other schools as it was to nature.
That pattern is not unfamiliar in a number of creative fields today, nor is
it incompatible with significant discovery and invention. It is not,
however, the pattern of development that physical optics acquired after
Newton and that other natural sciences make familiar today.
In this pre-paradigm phase, the science has not yet become an esoteric silo in which
the members of the field communicate exclusively to each other in the increasingly
specialised nomenclature of their specialisation.
As such the field doesn't progress and must wait for some discovery or some bright
mind to give rise to a theory with explanatory power that goes beyond any of the other
schools and which unifies the field under one paradigm.
When this does happen, the science enters its second phase as the field of physical
optics did with the work of Newton. This second phase is the paradigmatic phase of
normal science.
With the emergence of a theory with incomparable explanatory power, the field enters
its second phase which is its first stage as a science proper. As Kuhn says of the pre-
paradigm phase when remarking on the field of optics:
anyone examining a survey of physical optics before Newton may well
conclude that, though the field's practitioners were scientists, the net
result of their activity was something less than science.
With the emergence of the consensus establishing paradigm, the field becomes a
science proper. With this the field enters the stage of what Kuhn calls 'normal science'.
At this stage, scientists no longer have debates over first principles. They don't argue
about the nature of the field of study or about the correct methods or objects of study.
With the consensus that has gathered around the paradigmatic theory, scientists can
begin to take a certain amount of knowledge as foundational.
This is the beginning of what Kuhn calls the esotericisation of science. Scientists begin
to speak with each other in specialised journals and develop their own distinctive
terminology. There is no longer the need to speak in a way that is popularly
understandable since the status of the paradigm is now established.
Thus begins the work of normal science. The nature of normal science is, as we
covered in the previous episode, puzzle-solving. The scientists take the paradigmatic
theory for granted and begin to work on the puzzles suggested by this theory. For
example, there may be universal constants of quantitative laws invoked by the
paradigmatic theory whose precise measures haven't been established. It may employ
approximations that could be improved or suggest other puzzles of the same kind.
These are some of the types of further study that a paradigmatic theory orients
scientists towards. The science that takes place within a paradigm
is called normal science by Kuhn and it has the interesting trait according to Kuhn
that it does not seek novelty. Normal science is not seeking out unknowns. It is
seeking to test and extend the realm of the paradigm. What scientists are looking for in
the puzzle-solving of normal science is confirmation of the paradigmatic theory.
Novelty is undesirable because it does not fit in the model and so scientists don't
quite know what to do with it. But inevitably, scientists run into
these novelties. Kuhn calls these unexpected novelties anomalies and they are the entryway
to the third stage of a science - revolutionary or extraordinary science.
As normal science goes about the business of articulating and expanding its
paradigmatic theory, it encounters data that according to the paradigm it shouldn't. At
first this data is dismissed as being the result of a bad experiment or it is held lightly as
needing further explanation. But, as this anomaly in the data continues
to recur, it draws more and more attention in the field. Most of the time, these anomalies
succumb to the concentrated efforts of the scientists in the field.
One of Kuhn's examples of this comes from the century after Newton when scientists
struggled to reconcile their observations of the moon's motion with the predictions
derived from Newton's laws of motion and gravitation. Try as they might, they
couldn't reconcile the observations with the theory and many scientists suggested
adjustments to Newton's laws - which as Kuhn observed would have changed the
paradigm and defined a new puzzle but after much persistence, scientists preserved
the rules and in 1750 a scientist called Clairaut was able to show that it was only the
Maths that was wrong and Newton's theory could stand as before.
This example captures the first stages of the revolutionary process: an anomaly is
observed and can't be easily explained away. As the anomaly persists and still doesn't
succumb to the increased effort of the community to solve it, some suggest changing
the paradigm. In this Newtonian case, the puzzle was finally solved without the need
for a change.
But this doesn't always happen. And when it fails to be resolved, the anomaly
precipitates what Kuhn calls a crisis. The anomaly proves insoluble within the
confines of the paradigm and the field finds itself in a state of crisis.
As this crisis becomes more acute, we find the field becoming more and more akin to
the pre-paradigm state. The rules and fundamentals that had been implicit and taken
for granted so long as the paradigm reigned, now become articulated. But we find that
this articulation is far from homogenous and a number of different versions of the
theory emerge. During this period of crisis we see the
emergence of a new type of science that Kuhn calls revolutionary science or extraordinary
science. At this time certain scientists begin a different type of experimentation
in which they attempt to amplify and identify the structure of the anomaly.
Kuhn tells us that the thought experiment begins to play a role at this time.
Ultimately the crisis is brought to a resolution when such an individual invents the
solution and so births a new paradigm which reorients the field. This is the so-called
paradigm shift - the whole field is regathered around this revolutionary new
paradigm that reorients the field and sets it in motion once again after being churned
up by the crisis inducing anomaly. These paradigm-shifting individuals, Kuhn
tells us, fall into two categories: either they are young or else they are new to the field.
The reason for this is transparent enough: the individual needs to be green enough that
they haven't been fully indoctrinated into the old paradigm. While they have a deep
understanding of the field, they also crucially have a fresh enough perspective
that they can form alternative understandings.
The old guard are either too deeply immersed in the paradigm or too invested in it.
Even when the new paradigm has emerged, many of the old guard will not adopt it.
They will stick with the paradigm they know and attack the new one.
One notable example of this is of the famous English astronomer Fred Hoyle who
coined the term Big Bang in 1949 as a disparaging dismissal of the theory. Even up to
his death in 2001 he still refused to believe in the Big Bang having written that:
"The reason why scientists like the "big bang" is because they are
overshadowed by the Book of Genesis. It is deep within the psyche of
most scientists to believe in the first page of Genesis"
And so the new paradigm is not necessarily adapted by all in the field but wins out
over time. As the great originator of quantum theory Max Planck put it:
"A new scientific truth does not triumph by convincing its
opponents and making them see the light, but rather because its
opponents eventually die, and a new generation grows up that is
familiar with it." Or as the popular version of this saying goes:
"Science progresses one funeral at a time" With the maturation of a new generation,
the dust has settled. The revolution is complete and the vast majority of
scientists are now working within the new paradigm. And with that the cycle is complete:
the revolutionary science has birthed a new paradigm which enables the field
to move back into normal science. This then is Kuhn's structure of scientific
revolutions. Every science starts out in a pre- paradigmatic state before the birth of its first
paradigm. With the emergence of this first paradigmatic theory, the field achieves
a consensus that starts the esotericisation of the field whereby the scientists can take the
fundamentals for granted and so begins the work of normal science.
This normal science works at articulating and elaborating the paradigmatic theory and
in the process of doing so it encounters counterinstances - unexpected novelties in
the data. These novelties become anomalies which in turn become crises if no solution
is forthcoming from the old theory. And this crisis spurs on revolutionary
or extraordinary science which ultimately gives rise to a new paradigm. And with this new paradigm
the cycle begins again: the field returns to the work of normal science
and inevitably this turns up new anomalies which lead to new crises and new paradigms
and so the cycle goes on ad infinitum. That in brief is Kuhn's theory of the Structure
of Scientific Revolutions and that is everything that we have time for on this
episode of the living philosophy. On the next episode we are going to explore the criticisms
and the legacy of Kuhn's work. In the meantime if you enjoyed the video be sure
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