Why Trust Science?
Page 1
ADDITIONAL ADVANCE PRAISE FOR
WHY TRUST SCIENCE?
“This is a troubled time in the history of science and a perilous one for its reputation with the public, which is why now is exactly the right time for the fearless and brilliant Naomi Oreskes to explore this issue. The result is a don’t-miss investigation into the very human nature of research—its successes, its failures, and its fundamental integrity in the search for truth.”
—DEBORAH BLUM, Pulitzer Prize–winning author of The Poison Squad
“Why Trust Science? is a timely book by one of the world’s most important and trenchant observers of science and society. With misinformation and disinformation rampant today, caring citizens do not know what or whom to trust and have become confused about evidence, opinion, and partisan assertion. We need Oreskes’s clear look at how to recognize and use reliable knowledge. I cannot overstate the importance of this book now to scientists and citizens.”
—RUSH D. HOLT, CEO of the American Association for the Advancement of Science, former US House member
“Naomi Oreskes, who grabbed our attention with her keen insights into climate denial, now tackles a threat to the very basis of an informed democracy—attacks on science itself. Captivating, forceful, and grounded in critical analysis, Why Trust Science? is for anyone who cares about our world.”
—JANE LUBCHENCO, former head of the National Oceanic and Atmospheric Administration
“In this authoritative defense of science, noted scientist and science historian Naomi Oreskes presents her case, subjects it to scrutiny by experts, and responds to the points raised. Her approach itself is a metaphor for the self-correcting machinery of science and the iterative process that leads science toward a better understanding of the natural world.”
—MICHAEL E. MANN, Penn State University, author of The Hockey Stick and the Climate Wars
“This book poses an important and timely question. While acknowledging the ways that science can go off track and become unreliable, Oreskes provides a compelling and well-supported defense of science, arguing that its trustworthiness derives from its collective character rather than a particular method or the inherent objectivity of scientists.”
—ANGELA N. H. CREAGER, author of Life Atomic: A History of Radioisotopes in Science and Medicine
“An insightful, lucid, and accessible discussion of a highly complex issue of great urgency and importance. Oreskes’s call for a socially engaged science might lead to substantial changes in our conception of the role of science in society and the ways in which science is organized institutionally.”
—KARIM BSCHIR, ETH Zürich
WHY
TRUST
SCIENCE
?
The University Center for Human Values Series
Stephen Macedo, Editor
A list of tiltes in this series appears at the back of the book.
WHY
TRUST
SCIENCE
?
NAOMI
ORESKES
PRINCETON UNIVERSITY PRESS
PRINCETON AND OXFORD
Copyright © 2019 by Princeton University Press
Published by Princeton University Press
41 William Street, Princeton, New Jersey 08540
6 Oxford Street, Woodstock, Oxfordshire OX20 1TR
press.princeton.edu
All Rights Reserved
LCCN 2019937193
ISBN 9780691179001
eISBN 9780691189932
Version 1.0
British Library Cataloging-in-Publication Data is available
Editorial: Alison Kalett and Kristin Zodrow
Production Editorial: Sara Lerner
Text Design: Leslie Flis
Jacket Design: Amanda Weiss
Production: Jacqueline Poirier
Publicity: Sara Henning-Stout and Katie Lewis
Copyeditor: Brittany Micka-Foos
Trust, but verify.
—RONALD REAGAN
CONTENTS
Acknowledgments ix
Introduction 1
Stephen Macedo
Chapter 1 Why Trust Science? Perspectives from the History and Philosophy of Science 15
Chapter 2 Science Awry 69
Coda: Values in Science 147
Comments
Chapter 3 The Epistemology of Frozen Peas: Innocence, Violence, and Everyday Trust in Twentieth-Century Science 163
Susan Lindee
Chapter 4 What Would Reasons for Trusting Science Be? 181
Marc Lange
Chapter 5 Pascal’s Wager Reframed: Toward Trustworthy Climate Policy Assessments for Risk Societies 191
Ottmar Edenhofer and Martin Kowarsch
Chapter 6 Comments on the Present and Future of Science, Inspired by Naomi Oreskes 202
Jon A. Krosnick
Response
Chapter 7 Reply 215
Afterword 245
Notes 257
References 297
Contributors 335
Index 337
ACKNOWLEDGMENTS
This project would never have been completed without the considerable aid of my able and generous graduate student, Aaron van Neste, who helped me in countless ways. I am also deeply grateful to Erik Baker, Karim Bschir, Matthew Hoisch, Stephan Lewandowsky, Elisabeth Lloyd, Matthew Slater, Charlie Tyson, and an anonymous reviewer for comments on early drafts, and to all my students past and present, with whom I have thought through the question raised here. Whether Fleck was right about thought collectives, my own thinking has never been Cartesian.
Many of the ideas expressed here were developed over many years in the Science Studies Program at the University of California, San Diego (UCSD). I am grateful to UCSD colleagues past and present: Bill Bechtel, Craig Callender, Nancy Cartwright, Jerry Doppelt, Cathy Gere, Tal Golan, Philip Kitcher, Martha Lampland, Sandra Mitchell, Chandra Mukerji, Steven Shapin, Eric Watkins, and Robert Westman, with whom over many years I discussed the basis for scientific knowledge, truth, trust, proof, persuasion, and other weighty matters. I am also grateful to my current colleagues in the Department of the History of Science, Harvard University, with whom I have continued the conversation: particularly Allan Brandt, Janet Browne, Alex Cszisar, Peter Galison, and Sarah Richardson and to my colleagues in the “Assessing Assessment Project,” Keynyn Brysse, Dale Jamieson, Michael Oppenheimer, Jessica O’Reilly, Matthew Shindell, Mark C. Vardy, and Milena Wazeck, who have helped me to explore and analyze what it is that scientists really do.
This project would not have been possible without the backing and enthusiasm of Stephen Macedo, Melissa Lane, and the Princeton University Tanner Lecture committee; Al Bertrand, Alison Kalett, and Kristin Zodrow at Princeton University Press; and the financial support of the Tanner Foundation. [I declare no competing financial interests.]
Above all, I am grateful to all the scientists, past and present, who have worked hard to earn our trust. I hope that in some small way this book in part repays that debt.
WHY TRUST SCIENCE?
INTRODUCTION
Stephen Macedo
Science confronts a public crisis of trust. From the Oval Office in Washington and on news media around the world, the scientific consensus on climate change, the effectiveness of vaccines, and other important matters are routinely challenged and misrepresented. Doubts about science are sown by tobacco co
mpanies, the fossil fuels industry, free market think tanks, and other powerful organizations with economic interests and ideological commitments that run counter to scientific findings.1
Yet we know that scientists sometimes make mistakes, and that particular scientific findings now widely believed will turn out to be wrong. So why, when, and to what extent should we trust science?
These questions could hardly be more timely or important. As extreme weather events become more common, sea levels rise, and climate-induced migrations flow across borders, nations around the world confront mounting costs and humanitarian crises. Yet so-called experts do not always agree. A local television meteorologist may report that it is merely “some speculation from scientists” that global warming is contributing to extreme weather events, such as the “polar vortex” that hit the Upper Midwest and Northeast of the United States in late January 2019. On another channel, a scientist at a well-regarded research center insists that “we know why.… It’s all because of human activities increasing the greenhouse gases in the atmosphere that trap a lot more heat down by the surface.”2
As vitally important as climate science is to the future of humanity, that is only the tip of the iceberg. Are vaccines effective? Does the birth control pill cause depression? Is flossing good for your teeth? On these questions and so many others, scientists may agree yet doubts circulate. Who should we believe and why?
In Why Trust Science? Professor Naomi Oreskes provides clear and compelling answers to the questions of when and why scientific findings are reliable. She explains the basis for trust in science in highly readable prose, and illustrates her argument with vivid examples of science working as it should, and as it should not, on matters central to our lives. Readers will find here a vigorous defense of the trustworthiness of scientific consensus based not on any particular method or on the qualities of scientists, but on science’s character as a collective enterprise.
A distinguished scientist and historian of science, Professor Naomi Oreskes has also emerged as one of the world’s clearest and most influential voices on the role of science in society and the reality of man-made climate change.
This book grows out of the Princeton University Tanner Lectures on Human Values delivered by Professor Oreskes in late November 2016. On that occasion, four distinguished commentators, representing a variety of fields and perspectives, responded to Professor Oreskes’s two lectures. This book contains the lectures, the four commentaries, and an extended reply by Professor Oreskes, all revised and expanded.3
Readers will find in the chapters that follow an overview of the leading philosophical debates concerning the nature of scientific understanding, scientific method, and the role of scientific communities. Oreskes defends the role of values in science, discusses the relationship between science and religion, and sets out her own credo as a scientist and defender of science. Our four commentators offer their perspectives on these issues, and Oreskes closes with comments on the plight and promise of science in our time. A more detailed overview follows.
Why should we trust science? Professor Oreskes’s initial answer is crisp and clear: scientific knowledge is “fundamentally consensual” and understanding science properly can help us “address the current crisis of trust.”
Chapter 1 develops the problem of trust against the background of an account of philosophical debates about the nature of science and scientific method. In the eighteenth and nineteenth centuries, and before, trust often resided in “great men”: science was regarded as trustworthy insofar as the scientists were. Gradually the alternative idea was advanced that careful observation and adherence to scientific methods were the bases of progress. Oreskes also surveys the varieties of empiricism that dominated philosophies of science in the first half of the twentieth century, and the challenge advanced by Karl Popper, who regarded the essence of science not as verification but openness to falsifiability, or “fallibilism.”
Most important, on Oreskes’s account, was the emergence of the idea of science as a collective enterprise. The “sociological view” of science was first advanced by Ludwik Fleck, in the 1930s, who held that the “truly isolated investigator is impossible.… Thinking is a collective activity.” Oreskes endorses the idea that scientific progress depends on the collective institutions and practices of science, “such as peer-reviewed journals, and scientific societies through which scientists share data, grapple with criticisms, and adjust their views.”
The central importance of scientific communities, their worldviews, and practices is the core of Professor Oreskes’s view. When we focus on what scientists do, we find a variety of methods pursued with creativity and flexibility. She explores debates surrounding philosophies of science in the work of Pierre Duhem, W.V.O. Quine, Thomas Kuhn, and others. She describes the social epistemology developed by feminist philosophers and historians of science, including the contributions of Helen Longino, who helped establish the idea that, as Oreskes puts it, “objectivity is maximized … when the community is sufficiently diverse that a broad range of views can be developed, heard and appropriately considered.” Or, as she says later, “In Diversity There Is Epistemic Strength.”
Professor Oreskes thus defends the “social turn” in our understanding of science while also describing the sense of threat that greeted the idea that scientific realities are socially constructed. Remember the obvious, she advises: scientists are engaged in sustained and careful study of the natural world. The empirical dimension is critical, but scientific expertise is also communally organized: objectivity arises from social practices of criticism and correction, most successfully in scientific communities that are diverse, “non-defensive,” and self-critical.
We are warranted in placing “informed trust” in the “critically achieved consensus of the scientific community,” argues Professor Oreskes. Individual scientists make mistakes, especially when “they stray outside their domains of expertise,” and Oreskes provides some glaring examples. And science has no monopoly on insight into the natural world. Nevertheless, the practices and procedures of scientific communities increase the odds that scientific consensus is reliable.
We should trust the conclusions of the scientific community rather than the petroleum industry when it comes to climate change because the petroleum industry has a conflict of interest. It aims to profit by finding, developing, and selling petroleum resources, and it generally does that well. But those aims conflict with the pursuit of truth regarding climate change. As a general rule, we should be skeptical of the scientific claims of organizations guided by the profit motive or ones precommitted to an ideological point of view. Good science presupposes “that participants are interested in learning and have a shared interest in truth. It assumes that the participants do not have a major, intellectually compromising conflict of interest.”
And yet, scientists sometimes get things wrong, so, Professor Oreskes asks in chapter 2, how do we know that they are not wrong now? If our knowledge is perishable and incomplete, how “can we warrant relying on it to make decisions, particularly when the issues at stake are often socially or politically sensitive, economically consequential, and deeply personal?”
To investigate these important questions, Oreskes examines five examples of science gone awry: what do these examples have in common, and what can we learn from them?
The first is the “Limited Energy Theory,” popular in the late nineteenth century, which held that women should not participate in higher education, on the grounds that energy expended on studying would adversely affect their fertility. The withering criticism to which this theory was subjected by Dr. Mary Putnam Jacobi had, as the reader will learn, little immediate effect on male scientists.
Another example is the rejection of continental drift. Many American scientists in particular were hostile to the theory, which they argued was based on flawed “European” methodology.
A third example is eugenics, which is most closely associated nowadays with the Naz
is, but which had a wide variety of advocates and practitioners in the United States and other Western countries. Oreskes provides a fascinating account of the complex politics of eugenics in the United States and Europe.
Oreskes’s fourth example is hormonal birth control and the evidence that it often causes depression. Many women experience the onset of depression after beginning certain birth control formulas, and Professor Oreskes relates her own experience. Yet medical science long discounted as unreliable the self-reports of millions of women.
Oreskes’s final case is dental floss and the flurry of news reports asserting that there is no hard evidence that flossing is effective. Probing deeper, Oreskes argues that the lack of randomized trials to test for the effects of flossing hardly amounts to a lack of evidence.
From these diverse cases, Professor Oreskes draws some general lessons, which she groups under the themes of consensus, method, evidence, values, and humility.
The importance of hard-won scientific consensus, as an indicator of trustworthiness, holds up very well across the five cases. Oreskes also provides a fascinating discussion of the difficult question—vital to the role of science in a democracy—of non-expert opinion and how scientists should respond to it. Non-scientists—from nurses and midwives to farmers and fishermen—often have information or evidence relevant to science-based decisions. Patients have vital information about their symptoms. Yet, “Just because someone is close to an issue does not mean he or she understands it; conventional notions of objectivity assume distance for just this reason.” The cases help illustrate and sharpen the distinction between reliable scientific authority and the interest and ideology-based pseudoscientific dissent we witness surrounding climate change, evolution, and vaccines.
Drawing from her five examples, Oreskes warns of the “methodological fetishism” that leads some scientists to dismiss valuable forms of evidence because they do not fit their methodological precommitments. Evidence comes in a variety of forms.