Nonsense on stilts : how to tell science from bunk

324 Pages·2018·3.141 MB·English

by  Massimo Pigliucci

Nonsense on Stilts

Nonsense on Stilts
How to Tell Science from Bunk
Second Edition
massimo pigliucci
the university of chicago press chicago and london
The University of Chicago Press, Chicago 60637
The University of Chicago Press, Ltd., London
© 2010, 2018 by The University of Chicago
All rights reserved. Originally published 2010
Second Edition 2018
Printed in the United States of America
27 26 25 24 23 22 21 20 19 18 1 2 3 4 5 6
isbn- 13: 978- 0- 226- 49599- 6 (paper)
isbn- 13: 978- 0- 226- 49604- 7 (e- book)
doi: https://doi.org/10.7208/chicago/9780226496047.001.0001
Library of Congress Cataloging-in-Publication Data
Names: Pigliucci, Massimo, 1964– author.
Title: Nonsense on stilts : how to tell science from bunk / Massimo Pigliucci.
Description: Second edition. | Chicago : The University of Chicago Press, 2018. |
Includes bibliographical references and index.
Identifiers: LCCN 2018014122 | isbn 9780226495996 (pbk. : alk. paper) |
isbn 9780226496047 (e-book)
Subjects: LCSH: Pseudoscience—History. | Science—History.
Classification: LCC qi72.5.p77 p54 2018 | ddc 001.9—dc23
LC record available at https://lccn.loc.gov/2018014122
♾ This paper meets the requirements of ansi/niso z39.48- 1992 (Permanence of Paper).
Contents
Introduction Science versus Pseudoscience and the
“Demarcation Problem” 1
chapter 1 Frustrating Conversations 6
chapter 2 Hard Science, Soft Science 17
chapter 3 Almost Science 41
chapter 4 Pseudoscience 73
chapter 5 Blame the Media? 107
chapter 6 Debates on Science: The Rise of Think Tanks
and the Decline of Public Intellectuals 126
chapter 7 From Superstition to Natural Philosophy 156
chapter 8 From Natural Philosophy to Modern Science 177
chapter 9 The Science Wars I: Do We Trust Science
Too Much? 202
chapter 10 The Science Wars II: Do We Trust Science
Too Little? 221
chapter 11 The Problem and the (Possible) Cure: Scientism
and Virtue Epistemology 246
chapter 12 Who’s Your Expert? 267
Conclusion So, What Is Science after All? 288
Notes 293
Index 315

introduction
Science versus Pseudoscience and
the “Demarcation Problem”
“ The foundation of morality is to . . . give up pretending to believe that
for which there is no evidence, and repeating unintelligible proposi-
tions about this beyond the possibilities of knowledge.” So wrote Thomas
Henry Huxley, who thought— in the tradition of writers and philosophers
like David Hume and Thomas Paine— that we have a moral duty to dis-
tinguish sense from nonsense. That is also why I wrote this book. Ac-
cepting pseudoscientific untruths, or conversely, rejecting scientific truths,
has consequences for all of us, psychologically, financially, and in terms
of quality of life. Indeed, as we shall see, pseudoscience can literally kill
people.
The unstated assumption behind Huxley’s position is that we can tell
the difference between sense and nonsense, and in the specific case that
concerns us here, between good science and pseudoscience. As it turns
out, this is not an easy task. Doing so requires an understanding of the
nature and limits of science, of logical fallacies, of the psychology of be-
lief, and even of politics and sociology. A search for such understanding
constitutes the bulk of this book, but the journey should not end with its
last page. Rather, I hope readers will use the chapters that follow as a
springboard toward even more readings and discussions, to form a habit
of questioning with an open mind and constantly demanding evidence for
whatever assertion is being made by whatever self- professed authority—
including, of course, yours truly.
2 introduction
The starting point for our quest is what mid- twentieth- century philoso-
pher of science Karl Popper famously called “the demarcation problem.”
Popper wanted to know what distinguishes science from nonscience,
including, but not limited to, pseudoscience. He sought to arrive at the
essence of what it means to do science by contrasting it with activities
that do not belong there. Popper rightly believed that members of the
public— not just scientists or philosophers— need to understand and
appreciate that distinction, because science is too powerful and important,
and pseudoscience too common and damaging, for an open society to
afford ignorance on the matter.
Like Popper, I believe some insight into the problem might be gleaned
by considering the differences between fields that are clearly scientific and
others that just as clearly are not. We all know of perfectly good examples
of science, say, physics or chemistry, and Popper identified some exem-
plary instances of pseudoscience with which to compare them. Two that
he considered in some detail are Marxist theories of history and Freudian
psychoanalysis. The former is based on the idea that a key to understand-
ing history is the ongoing economic struggle between classes, while the
latter is built around the claim that unconscious sex drives generate psy-
chological syndromes in adult human beings.
The problem is, according to Popper, that those two ideas, rather para-
doxically, explain things a little too well. Try as you may, there is no his-
torical event that cannot be recast as the result of economic class struggle,
and there is no psychological observation that cannot be interpreted as
being caused by an unconscious obsession with sex. The two theories, in
other words, are too broad, too flexible with respect to observations, to
tell us anything interesting. If a theory purports to explain everything,
then it is likely not explaining much at all. Popper claimed that theories
like Freudianism and Marxism are unscientific because they are “unfal-
sifiable.” A theory that is falsifiable can be proven wrong by some con-
ceivable observation or experiment. For instance, if I said that adult dogs
are quadrupedal (four- legged) animals, one could evaluate my theory by
observing dogs and taking notes on whether they are quadrupeds or bi-
peds (two- legged). The observations would settle the matter empirically.
Either my statement is true or it isn’t, but it is a scientific statement—
according to Popper— because it has the potential to be proven false by
observations.
Conversely, and perhaps counterintuitively, Popper thought that scien-
tific theories can never be conclusively proven because there is always the
science versus pseudoscience 3
possibility that new observations— hitherto unknown data— will falsify
them. For instance, I could observe thousands of four- legged dogs and
grow increasingly confident that my theory is right. But then I could turn
a corner and see an adult two-l egged dog: there goes the theory, falsified
by one negative result, regardless of how many positive confirmations I
have recorded on my notepad. In this view of the difference between sci-
ence and pseudoscience, then, science makes progress not by proving its
theories right— because that’s impossible— but by eliminating an increas-
ing number of wrong theories. Pseudoscience, however, does not make
progress because its “theories” are so flexible. Pseudoscientific theories
can accommodate any observation whatsoever, which means they do not
actually have any explanatory teeth.
Most philosophers today would still agree with Popper that we can
learn about what science is by contrasting it with pseudoscience (and
nonscience), but his notion that falsificationism is the definitive way to
separate the two has been severely criticized. A moment of reflection re-
veals that Popper’s solution is a bit too neat to work in the messiness of the
real world. Consider again my example of the quadrupedal dogs. Suppose
we do find a dog with only two legs, perhaps because of a congenital de-
fect. Maybe our bipedal dog has even learned to move around by hopping
on its two hind legs, like kangaroos do (in fact, such abnormal behavior
has occasionally been observed in dogs and other normally quadrupedal
mammals; just google “bipedal dog” to see some amusing examples). Ac-
cording to Popper, we would have to reject the original statement— that
dogs are quadrupeds— as false. But as any biologist, and simple common
sense, would tell you, we would be foolish to do so. Dogs are quadrupeds,
exceptions notwithstanding. The new observation requires, not that we
reject the theory, but that we slightly modify our original statement and
say that dogs are normally quadrupedal animals, though occasionally one
can find specimens with developmental abnormalities that make them
look and behave like bipeds.
Similarly, philosophers agree that scientists do not (and should not)
reject theories just because they initially fail to account for some observa-
tion. Rather, they keep working at them to see why the data do not fit and
how the theory might be modified in a sensible manner. Perhaps the new
observations are exceptional and do not really challenge the core of a the-
ory, or maybe the instruments used by scientists (whether sophisticated
telescopes or simple gauges) are giving incorrect readings and need to be
fixed— many things may give rise to discrepancies. This idea of modifying