Introduction to the philosophy of science

What are the aims of science?

What is the role of observations and experiments in obtaining scientific knowl­edge?

How do scientists justify their claims? What is a scientific proof? What is a scientific law?

Arc there methods for making scientific discoveries? How does scientific knowledge advance and grow? How do the historical and cultural settings in which scientific work occurs affect

the content and quality of such work? Does science employ or require a special language?

Science itself is made up of many subdisciplines: physics, astronomy, chem­istry, biology, psychology, sociology, anthropology, and medicine, to name a few. The presence of so many different fields within science raises interesting questions about what it means to be a science and whether a single method is common to all sciences. Philosophy of science thus addresses also the following sorts of questions:

different methods and forms of explanation for various branches of science? How do physical, biological, and social sciences differ from one another? Can some sciences be reduced to others?

Finally, philosophy of science is concerned with specific issues that arise in connection with particular fields of science. For example, while experimentation plays a major role in some sciences, in others, such as astronomy, it does not. Some other discipline-specific questions are these;

Does the existence of free will pose a special problem for a science of human

behavior?

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2 Introduction

concepts, the relation between evidence and theory, and the nature of scientific explanation. In their desire to be precise, they made extensive use of the language and techniques of symbolic logic. Despite many differences in points of view, the logical positivists and logical empiricists generally were concerned with emphasizing such distinctions as

the demarcation between scientific knowledge and other types of knowledge,

the difference between facts and values,

the difference between the language used to state observations and that used to

refer to theoretical entities, and the difference between how theories are discovered and how they are justified.

Logical empiricists and logical positivists were also concerned with establishing clear meanings for all the terms used in science. Some approached this problem by search­ing for a verifiability criterion of meaning while others, particularly scientists them­selves, tried to formulate operational definitions of scientific terms. These efforts were closely related to their concern with providing a solid foundation for scientific theorizing by linking it firmly to an observational basis. Although they believed that justification rather than discovery was the proper concern of science, they shared an optimism about the ability of science to provide genuine knowledge of the features of an independently existing world.

At the time of World War Two, many of these philosophers left Europe for England and the United States where their works have significantly affected the development of philosophy of science in English-speaking countries. Even at the level of undergraduate education, their influence has been important. Carl G. Hempel, who came to America from Berlin, for example, has literally defined the philosophy of the natural sciences for generations of students who first learned about the subject from his introductory text, Philosophy of Natural Science (1966). The power and broad influence of the general approach outlined by Hempel in this work justifies calling it "the standard view" of philosophy of science.

During the past twenty-five years, however, many criticisms have been raised against perceived faults of the standard view. (Indeed, Hempel himself has criticized some of its features.) A major objection is that the standard view fails to take account of the bearing of history of science on the philosophy of science. Critics of the standard view cite Thomas Kuhn's Structure of Scientific Revolutions (1962, 1970), which argues that most scientific textbooks ignore history and distort the real nature of progress in science by presenting it as a series of accumulations of new discoveries that straightforwardly build on and add to knowledge already attained. Kuhn draws attention to the revolutionary character of science—its replacement of outworn the­ories by newer ones that are so different from the old that the two do not share the same problems or even a common language. He also draws attention to the "irra­tional" aspects of changes in science, that is to say, those features of scientific change that cannot be accounted for entirely in terms of scientists' allegiance to "facts" and logic- Kuhn argues that only a refusal to take seriously the history of science could account for the gross distortion presented in scientific textbooks.

Appealing to Kuhn's account of science, critics of the standard view of philos­ophy of science say that it embodies and promotes an ahistorical view of scientific activity by emphasizing the logical characteristics of science while ignoring the

” cultural context of scientific activity, which strongly influences the style of the en­terprise and the content of its results. Furthermore, critics say, failure to take account of the rhetorical features of scientific discourse can only lead to a distorted notion of how science really works. The values of society and of individual practitioners of science, they say, influence not only the choice of problems and the amount of effort devoted to their solution, but also the interpretation of the results. They maintain that so-called facts can only be grasped through theories, which are the creations of members of a specific culture, and are never completely free of the values and aspirations of that culture.

Both the standard view and that of its critics have merits and shortcomings. Both views are likewise too complex to state succinctly without distortion and over­simplification; the above brief synopsis is intended only to introduce the reader to the subject. The ensuing chapters will survey many aspects of the dispute and will examine the reasons offered in support of the various positions.

The approach to the philosophy of science exemplified in this work does not fall neatly into either of the two main categories briefly outlined. The authors of this text are all members of a Department of History and Philosophy of Science. The marriage

I between history and philosophy in the Department is not merely one of convenience between philosophers and historians each of whom happens to be concerned with science. Instead, the Department was founded because the members believe that the study of the philosophy of science must be informed by an understanding of the

' historical and social context of science, as well as by a grasp of the workings of science itself. At the same time, the general approach of this book disavows the extreme forms of relativism and skepticism that characterize some of the more stri­dent critics of the standard view.

-' Part One of this book takes up topics requisite for any adequate introduction to the philosophy of science: Explanation; Induction and Confirmation; Realism and the t Nature of Scientific Theories: and Scientific Change: Perspectives and Proposals.

'' These four chapters outline and discuss fundamental issues in philosophy of science and form the foundation for discussions in the remaining chapters of the book. In Part One, the reader is introduced to the pertinent history of the topics discussed as well as to the vocabulary, techniques, and most important issues in contemporary philos­ophy of science. The intention of the authors in each case is to presume no prior knowledge of philosophy of science, but to lead the reader to an appreciation of some of the knottiest problems that concern contemporary philosophers of science. In the first chapter, "Scientific Explanation," Wesley C. Salmon discusses the elements involved in the special kind of understanding of our world and what takes place within it that is provided by the various sciences. In the second chapter, The Confirmation of Scientific Hypotheses," John Earman and Wesley C. Salmon deal with questions concerning the relationship between empirical evidence and scientific hypotheses, laws, and theories. In the course of the discussion they consider the nature of induc­tive reasoning and the meanings of the concept of probability. Chapter 3, by Clark Glymour, considers the major traditional arguments against literal belief in the claims

of science and a range of responses to those arguments. In the fourth chapter, J. E. McGuire discusses the nature of scientific change and progress in relation to social context and historical development.

In the remaining seven chapters, each of which deals with the philosophy of a special area of science, the authors assume that the reader is familiar with the issues addressed in the first four chapters, though some topics depend less heavily on this than others. The chapters in Parts Two through Four can be read independently of one another, although they do contain references to the materials covered in other chap­ters.

The philosophy of physical sciences is covered in Part Two (Chapters 5 and 6). In "The Philosophy of Space and Time," John D. Norton introduces questions central to recent work in philosophy of space and time and illustrates how philosoph­ical ideas about verification, conventions, realism, and theory reduction are applied in physical theories of space and time. In "Determinism in the Physical Sciences," John Barman surveys the implications of classical physics, the special and general theories of relativity, and quantum mechanics for the doctrine that the world evolves in a deterministic manner.

Merrilee H. Salmon