Theory and Reality
Page 1
SCIENCE AND ITS CONCEPTUAL FOUNDATIONS A SERIES EDITED BY DAVID L. HULL
PETER GODFREY-SMITH
For my parents
Preface
A Note for Those Teaching with the Book
1 Introduction
i.i Setting Out
1.2 The Scope of the Theory
1.3 What Kind of Theory?
I.4 Three Answers, or Pieces of an Answer
r.5 Historical Interlude: A Sketch of the Scientific Revolution
Further Reading
2 Logic Plus Empiricism
z.i The Empiricist Tradition
z.z The Vienna Circle
z.3 Central Ideas of Logical Positivism
2.4 Problems and Changes
2.5 Logical Empiricism
z.6 On the Fall of Logical Empiricism
Further Reading
3 Induction and Confirmation
3. r The Mother of All Problems
3.2 Induction, Deduction, Confirmation, and Explanatory Inference
3.3 The Ravens Problem
3.4 Goodman's "New Riddle of Induction"
Further Reading
4 Popper: Conjecture and Refutation •
4.r Popper's Unique Place in the Philosophy of Science
4.z Popper's Theory of Science
4.3 Popper on Scientific Change
4.4 Objections to Popper on Falsification
4.5 Objections to Popper on Confirmation
4.6 Further Comments on the Demarcation Problem
Further Reading
5 Kuhn and Normal Science •
5.1 "The Paradigm Has Shifted"
5.2 Paradigms: A Closer Look
5.3 Normal Science
5.4 Anomaly and Crisis
5.5 Wrap-up of Normal Science
Further Reading
6 Kuhn and Revolutions •
6.1 Considerable Upset
6.z Revolutions and Their Aftermath
6.3 Incommensurability, Relativism, and Progress
6.4 The X-Rated "Chapter X"
6.5 Final Thoughts on Kuhn
Further Reading
7 Lakatos, Laudan, Feyerabend, and Frameworks •
7.1 After Structure
7.z Lakatos and Research Programs
7.3 Laudan and Research Traditions
7.4 Anything Goes
7.5 An Argument from History That Haunts Philosophy
7.6 Pluralism and the Ramblings of Madmen
7.7 Taking Stock: Frameworks and Two-Process Theories of Science
Further Reading
8 The Challenge from Sociology of Science •
8.1 Beyond Philosophy?
8.2. Robert Merton and the "Old" Sociology of Science
8.3 The Rise of the Strong Program
8.4 Leviathan and Latour
Further Reading
9 Feminism and Science Studies •
9.1 "Science Is Political"
9.z The Man of Reason
9.3 The Case of Primatology
9.4 Feminist Epistemology
9.5 Science Studies, the Science Wars, and the Sokal Hoax
Further Reading
10 Naturalistic Philosophy in Theory and Practice •
io.i What Is Naturalism?
io.z Quine, Dewey, and Others
10.3 The TheoryLadenness of Observation
Further Reading
11 Naturalism and the Social Structure of Science •
11.1 Science as a Process
11.2. Kircher and the Division of Scientific Labor
1111.3 Social Structure and Empiricism
Further Reading
12 Scientific Realism •
112..11 Strange Debates
12..2. Approaching Scientific Realism
11 z.3 A Statement of Scientific Realism
12.4 Challenges from Traditional Empiricism
11z.5 Metaphysical Constructivism
11 z.6 Van Fraassen's View
Iz.7 Representation, Models, and Truth (Optional Section)
Further Reading
13 Explanation •
13.1 Knowing Why
113.z The Rise and Fall of the Covering Law Theory of Explanation
13.3 Causation, Unification, and More
13.4 Laws and Causes (Optional Section)
Further Reading
14 Bayesianism and Modern Theories of Evidence •
14.1 New Hope
14.2 Understanding Evidence with Probability
14.3 The Subjectivist Interpretation of Probability
14.4 Assessing Bayesianism
14.5 Scientific Realism and Theories of Evidence
14.6 Procedural Naturalism (Optional Section)
Further Reading
15 Empiricism, Naturalism, and Scientific Realism? •
15.1 A Muddy Paste?
15.2-The Apparent Tensions
15.3 Empiricism Reformed
15.4 A Last Challenge
15.5 The Future
Glossary •
References •
Index •
This book is based mainly on lectures given at Stanford University during the last eleven years. So the book is a distillation of lectures, but not only of lectures. It also bears the influence of innumerable comments, questions, and papers by students over that time, together with remarks made by colleagues and friends.
The book is written primarily for students, but it is intended to be accessible to a fairly wide audience. I assume no background knowledge in philosophy at all in the reader. My primary aim is to introduce some of the main themes in the philosophy of science, while simultaneously telling an accessible and interesting story about how the field has developed in the last one hundred years or so. In telling this story I have been led to describe the connections between philosophy and other disciplines, and the changing intellectual climate in which theories of science have been offered, in more detail than many introductory books do. I have also tried, in some places, to capture some of the atmosphere of the debates, and the personalities of the protagonists.
Another aim of the book is the outline and defense of a particular point of view, but I have concentrated that discussion mostly in the final third of the book. Philosophy of science seems to me to be still in a state of considerable ferment. That poses a choice for the author of a book like this; one can either abstract away from the disorder and uncertainty, and lay down one particular vision, or one can use the disputes to tell a story about the field-how did we get to where we are now? I have mostly chosen the latter approach. This feature of the book is partly due to the inspiration of John Heilbroner's classic history of economic thought, The Worldly Philosophers.
For comments on this work I am very grateful to Fiona Cowie, Michael Devitt, Stephen Downes, Richard Francis, Michael Friedman, Lori Gruen, Tania Lombrozo, Denis Philips, J. D. Trout, Allen Wood, and Rega Wood. Two anonymous referees for the University of Chicago Press also made helpful criticisms.
For detailed and exceptionally useful comments on entire near-final drafts, resulting in numerous improvements, I am indebted to Karen Bennett, Kim Sterelny, and Michael Weisberg.
Other improvements resulted, as always, from the insight, good sense, deft touch, and unique perspective of David Hull, the editor of the Science and Its Conceptual Foundations series. At the University of Chicago Press, Susan Abrams was constantly enthusiastic about the project and did a great job throughout. It is a rare pleasure to work with an editor like Susan. I am also grateful to Stanford University for much financial and intellectual support over the last eleven years. This support has included several grants, including most recently a Martha Sutton Weeks Fellowship.
Finally, as this is a book written primarily
for students, this seems an appropriate place for me to express my enduring gratitude to the four fundamental mentors who taught, guided, and encouraged me when I was a student: Kim Sterelny, Michael Devitt, Stephen Stich, and Philip Kitcher.
The book is organized chronologically, especially until chapter z o, and following the chronology is probably the most appropriate way to teach a course using the book. However, there is also a way to use the book in a course that follows a more thematic organization. Approached this way, chapters i and z are background; chapters 3, 4, io, and 14 form a block focused on issues about evidence, testing, and theory choice; chapters 5ii discuss scientific change and the social organization of science, along with the interaction between these topics and epistemological questions; chapters iz and 13 address issues more on the metaphysical than the epistemological side of the philosophy of science. The book might also be used, of course, as a supplement to lectures and readings with a very different organization.
The "Further Reading" sections tend to contain quite a lot of primary material, including some difficult works and works intended to give the flavor of recent discussion (such as papers from the Proceedings of the Philosophy of Science Association). This is especially true of the later chapters. The level of difficulty found in the "Further Reading" escalates more quickly than the difficulty of the text itself (or so I hope). The glossary, in contrast, is intended to be very elementary, a tool for those coming to the book with little or no background in the area.
1.1 Setting Out
This book is a survey of roughly one hundred years of argument about the nature of science. We'll look at a hundred years of argument about what science is, how it works, and what makes science different from other ways of investigating the world. Most of the ideas we will examine fall into the field called "philosophy of science," but we will also spend a good deal of time looking at ideas developed by historians, sociologists, psychologists, and others.
The book mostly has the form of a "grand tour" through the decades; ideas will be discussed in roughly the order in which they appeared. Note the word "roughly" in the previous sentence; there are exceptions to the historical structuring of the book, and I will point out some of them as they arise.
Why is it best to start with older ideas and work through to the present? One reason is that the historical development of general ideas about science is itself an interesting topic. Another reason is that the philosophy of science has been in a state of fermentation and uncertainty in recent years. A good way to understand the maze of options and opinions in the field at the moment is to trace the path that brought us to the state we're in now. But this book does not only aim to introduce the options. I will often take sides as we go along, trying to indicate which developments were probably wrong turns or red herrings. Other ideas will be singled out as being on the right track. Then toward the end of the book, I will start trying to put the pieces together into a picture of how science works.
Philosophy is an attempt to ask and answer some very basic questions about the universe and our place within it. These questions can sometimes seem far removed from practical concerns. But the debates covered in this book are not of that kind. Though these debates are connected to the most abstract questions about thought, knowledge, language, and reality, they have also turned out to have an importance that extends well outside of philosophy. They have made a difference to developments in many other academic fields, and some of the debates have reverberated much further, affecting discussions of education, medicine, and the proper place of science in society.
In fact, throughout the latter part of the twentieth century, all the fields concerned with the nature of science went on something of a roller-coaster ride. Some people thought that work in the history, philosophy, and sociology of science had shown that science does not deserve the dominating role it has acquired in Western cultures. They thought that a set of myths about the trustworthiness and superiority of mainstream science had been thoroughly undermined. Others disagreed, of course, and the resulting debates swirled across the intellectual scene, frequently entering political discussion as well. From time to time, scientific work itself was affected, especially in the social sciences. These debates came to be known as the "Science Wars," a phrase that conveys a sense of how heated things became.
The Science Wars eventually cooled down, but now, as I write these words, it is fair to say that there is still a great deal of disagreement about even the most basic questions concerning the nature and status of scientific knowledge. These disagreements usually do not have much influence on the day-to-day practice of science, but sometimes they do. And they have huge importance for general discussions of human knowledge, cultural change, and our overall place in the universe. This book aims to introduce you to this remarkable series of debates, and to give you an understanding of the present situation.
1.2 The Scope of the Theory
If we want to understand how science works, it seems that the first thing we need to do is work out what exactly we are trying to explain. Where does science begin and end? Which kinds of activity count as "science"?
Unfortunately this is not something we can settle in advance. There is a lot of disagreement about what counts as science, and these disagreements are connected to all the other issues discussed in this book.
There is consensus about some central cases. People often think of physics as the purest example of science. Certainly physics has had a heroic history and a central role in the development of modern science. Molecular biology, however, is probably the science that has developed most rapidly and impressively over the past fifty years or so.
These seem to be central examples of science, though even here we en counter hints of controversy. A few have suggested that theoretical physics is becoming less "scientific" than it used to be, as it is evolving into an esoteric, mathematical modelbuilding exercise that has little contact with the real world (Horgan 1996). And molecular biology has recently been acquiring connections with business and industry that make it, in the eyes of some, a less exemplary science than it once was. Still, examples like these give us a natural starting point. The work done by physicists and molecular biologists when they test hypotheses is science. And playing a game of basketball, no matter how well one plays, is not doing science. But in the area between these clear cases, disagreement reigns.
At one time the classification of economics and psychology as sciences was controversial. Those fields have now settled into a scientific status, at least within the United States and similar countries. (Economics retains an amusing qualifier; it is often called "the dismal science," a phrase due to Thomas Carlyle.) There is still a much-debated border region, however, and at the moment this includes areas like anthropology and archaeology. At Stanford University, where I teach, this kind of debate was one element of a process in which the Department of Anthropology split into two separate departments. Is anthropology, the general study of humankind, a fully scientific discipline that should be closely linked to biology, or is it a more "interpretive" discipline that should be more closely connected to the humanities?
The existence of this gray area should not be surprising, because in contemporary society the word "science" is a loaded and rhetorically powerful one. People will often find it a useful tactic to describe work in a borderline area as "scientific" or as "unscientific." Some will call a field scientific to suggest that it uses rigorous methods and hence delivers results we should trust. Less commonly, but occasionally, a person might call an investigation scientific in order to say something negative about it-to suggest that it is dehumanizing, perhaps. (The term "scientistic" is more often used when a negative impression is to be conveyed.) Because the words "science" and "scientific" have these rhetorical uses, we should not be surprised that people constantly argue back and forth about which kinds of intellectual work count as science.
The history of the term "science" is also relevant here. The current uses of the words "science
" and "scientist" developed quite recently. The word "science" is derived from the Latin word "scientia." In the ancient, medieval, and early modern world, "scientia" referred to the results of logical demonstrations that revealed general and necessary truths. Scientia could be gained in various fields, but the kind of proof involved was what we would now mostly associate with mathematics and geometry. Around the seventeenth century, when modern science began its rise, the fields that we would now call science were more usually called "natural philosophy" (physics, astronomy, and other inquiries into the causes of things) or "natural history" (botany, zoology, and other descriptions of the contents of the world). Over time, the term "science" came to be used for work with closer links to observation and experiment, and the association between science and an ideal of conclusive proof receded. The current senses of the term "science" and the associated word "scientist" are products of the nineteenth century.
Given the rhetorical load carried by the word "science;' we should not expect to be able to lay down, here in chapter i, an agreed-on list of what is included in science and what is not. For now we will have to let the gray area remain gray.
A further complication comes from the fact that philosophical (and other) theories differ a lot in how broadly they conceive of science. Some writers use terms like "science" or "scientific" for any work that assesses ideas and solves problems in a way guided by observational evidence. Science is seen as something found in all human cultures, even though the word is a Western invention. But there are also views that construe "science" more narrowly, seeing it as a cultural phenomenon that is localized in space and time. For views of this kind, it was only the Scientific Revolution of the sixteenth and seventeenth centuries in Europe that gave us science in the full sense. Before that, we find the initial "roots" or precursors of science in ancient Greece, some contributions from the Arab world and from the Scholastic tradition in the late Middle Ages, but not much else. So this is a view in which science is treated as a special social institution with a definite history. Science is something that descends from specific people and places, and especially from a key collection of Europeans, including Copernicus, Kepler, Galileo, Descartes, Boyle, and Newton, who all lived in the sixteenth and seventeenth centuries.