Philosophy Now-Aug-Sept 2019

(Joyce) #1
10 Philosophy Now ●August/September 2019

hypothesis for how mass warps spacetime, any more than Newton
offered one about how gravity works. ‘Warped spacetime’ is an
explanation of gravity without an explanation. But again that does-
n’t matter in order for the theory to be useful. And as the evidence
soon showed, the equations Einstein deduced are more accurate
(for predicting planetary motion, say) than Newton’s laws.

Twentieth Century Philosophy of Science
In 1919 the British physicist Arthur Eddington led an expedi-
tion to the island of Principe off the West coast of Africa to
photograph a total eclipse of the Sun. The aim was to test gen-
eral relativity by measuring how much the light from stars was
bent by the Sun’s gravity (if space is warped by mass then light
will noticeably bend around large enough masses). The deflec-
tion was twice what Newtonian gravity could account for and
much closer to Einstein’s predictions. They made headlines
around the world and turned Einstein into the byword for sci-
entific genius that he remains to this day.
At the time a young Karl Popper (1902-1994) was attending
the University of Vienna. He was impressed by the fact that gen-
eral relativity made such definite predictions. It was a bold strat-
egy, because if the evidence didn’t support it, the theory would
be shown to be wrong. Popper decided that this was a defining
feature of science: a theory could only count as scientific if it
could in principle be shown to be wrong. It has to be falsifiable.
According to this view, Aristotle’s claim that freefall speed is
proportional to mass is scientific, because a simple experiment
can determine whether it is true or not. And Galileo had shown
it isn’t true. But according to Popper it’s still a scientific claim,
because being true isn’t a defining feature of a scientific theory.
Even as Popper was developing his theory of falsifiability, sci-
entists were already pointing out that actually, that’s not how sci-
entists work. Ludwik Fleck, a biologist, introduced the idea of a
‘thought collective’ – a group of scientists who share some common
theory and working practices, their scientific method, and who
collaborate to develop that research structure to its fullest poten-
tial. Michael Polanyi, a professor of chemistry, made a similar
point. Science, in his experience, was not a single objective method
that could simply be prescribed and followed; rather scientists put
into practice the philosophy and methods they have been taught
by other scientists. Essentially, once they have been initiated into
a thought collective, they contribute to that collective. The physi-
cist Max Planck, like Einstein, never fully accepted the interpre-
tations of quantum mechanics given by younger scientists; but he
observed that “a new scientific truth does not triumph by con-
vincing 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.” So a prominent biologist, chemist, and
physicist were all saying that in their professional experience, sci-
ence did not work as philosophers such as Popper thought it
should, and there isn’t one scientific method, there are many. And
in 1962 Thomas Kuhn (1922-1996) published The Structure of Sci-
entific Revolutions , which made everyone pay attention to the grow-
ing conviction that science is not the pristine singular enterprise
philosophers had been trying to describe.
The structure of scientific progress referred to in Kuhn’s title
has three parts. There is a ‘pre-science’ period, when some fea-

ture of the world has no scientific explanation. People speculate
and offer suggestions until one comes along in which a sufficient
number of scientists see enough potential to commit time and
resources to researching it. Rather than try to destroy the idea, as
Popper recommended, if experiments designed in terms of this
explanation produce results that match the theory, scientists col-
laborate to enhance the growing paradigm (the paradigm is the
overarching type of explanation being used). If the paradigm is
any good this can be a very productive period because it gives the
scientists a conceptual framework to explore that will raise ques-
tions that wouldn’t occur outside the paradigm. Such puzzle solv-
ing within a paradigm is what Kuhn called ‘normal science’. How-
ever, no matter how good a given paradigm is, we can never know
for sure that some new discovery will not undermine it. It hap-
pened to Aristotle’s paradigm of nature; it happened to Newton’s;
and no scientist can guarantee it won’t happen to our current
models, either. If, or more likely when it happens, at first there can
be some tinkering to protect the old paradigm, as Kuhn argued
from studying the history of science. But as the anomalies build
up and eventually plunge the extant paradigm into crisis, a new
paradigm will be required which can account for everything the
old paradigm could explain plus the stuff it couldn’t – just as gen-
eral relativity explains behaviour that Newtonian gravity can’t.
Paul Feyerabend (1924-1994) was one of four people person-
ally thanked by Kuhn in the Preface to The Structure of Scientific
Revolutions. Feyerabend had turned down an offer to be Popper’s
research assistant. Having started his academic career as a physi-
cist he was well qualified to make that judgement. As the history
of gravity shows, explanation, demonstration, and usefulness have
all played a critical role in science; and Feyerabend was concerned
that any reductive scientific method, such as Popper was advo-
cating, would have ruled out some part of that history. No one
likes being told what to think or do, and scientists are no excep-
tion. Rather, Feyerabend thought that the only prescription for
science that could accommodate every stumble and leap is
methodological anarchy, or as Feyerabend put it, anything goes.
He took the view that by far the most important criterion is that
a theory should be useful – it didn’t matter to who, or what for.
Feyerabend gave this insight: “Having listened to one of my anar-
chistic sermons, Professor Wigner exclaimed: ‘But surely, you
do not read all the manuscripts which people send you, you must
throw most of them into the wastepaper basket.’ I most certainly
do. ‘Anything goes’ does not mean that I shall read every single
paper that has been written – God forbid! –it means that I make
my selection in a highly individual and idiosyncratic way, partly
because I can’t be bothered to read what doesn’t interest me –
and my interests change from week to week and day to day –
partly because I am convinced that humanity and even science
will profit from everyone doing their own thing” ( Against Method ,
1975). Whatever anyone thinks should or shouldn’t qualify as
science, the fact is that science is done by people. Some of those
people are rationalists, some are empiricists, and some are prag-
matists; and no matter what rules are imposed, people break them.
© WILL BOUWMAN 2019
Will Bouwman is the author ofEinstein on the Train and Other
Stories: How to Make Sense of the Big Bang, Quantum Mechanics
and Relativity.

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