What is required for something to be evidence for a hypothesis? In this fascinating, elegantly written work, distinguished philosopher of science Peter Achinstein explores this question, rejecting typical philosophical and statistical theories of evidence. He claims these theories are much too weak to give scientists what they want--a good reason to believe--and, in some cases, they furnish concepts that mistakenly make all evidential claims a priori. Achinstein introduces four concepts of evidence, defines three of them by reference (...) to "potential" evidence, and characterizes the latter using a novel epistemic interpretation of probability. The resulting theory is then applied to philosophical and historical issues. Solutions are provided to the "grue," "ravens," "lottery," and "old-evidence" paradoxes, and to a series of questions. These include whether explanations or predictions furnish more evidential weight, whether individual hypotheses or entire theoretical systems can receive evidential support, what counts as a scientific discovery, and what sort of evidence is required for it. The historical questions include whether Jean Perrin had non-circular evidence for the existence of molecules, what type of evidence J. J. Thomson offered for the existence of the electron, and whether, as is usually supposed, he really discovered the electron. Achinstein proposes answers in terms of the concepts of evidence introduced. As the premier book in the fabulous new series Oxford Studies in Philosophy of Science, this volume is essential for philosophers of science and historians of science, as well as for statisticians, scientists with philosophical interests, and anyone curious about scientific reasoning. (shrink)

The essays in this volume address three fundamental questions in the philosophy of science: What is required for some fact to be evidence for a scientific ...

Offering a new approach to scientific explanation, this book focuses initially on the explaining act itself.

There is a type of explanation frequently employed in the sciences, particularly the quantitative ones, that I intend to focus on. It seeks to understand some phenomenon or regularity that occurs in a type of system S by deriving an equation describing that phenomenon or regularity from a set of equations that govern S. I want to propose a way of understanding such explanations.

In this systematic study, Professor Achinstein analyzes such concepts as definitions, theories, and models, and contrasts his view with currently held positions that he finds inadequate.

This anthology presents work on major topics surrounding the concept of evidence as employed in the empirical sciences. Focusing on the "classificatory" concept of evidence rather than the quantitative "degree of confirmation," the selections include Carl G. Hempel's satisfaction definition, R.B. Braithwaite's hypothetic-deductive view, N.R. Hanson's account of retroduction, Nelson Goodman's entrenchment theory, probability definitions discussed by Rudolf Carnap and Wesley Salmon, Clark Glymour's bootstrap theory, and a view of Achinstein's that combines probability and explanation.

In this book, Peter Achinstein proposes and defends several objective concepts of evidence. He then explores the question of whether a scientific method, such as that represented in the four "Rules for the Study of Natural Philosophy" that Isaac Newton invoked in proving his law of gravity, can be employed in demonstrating how the proposed definitions of evidence are to be applied to real scientific cases.

Newton deplored speculation in science, Einstein reveled in it. What exactly are scientific speculations? Are they ever legitimate? Are they subject to constraints? This book defends a pragmatic approach to these issues and applies it to speculations within science and to speculations about science.

Jean Perrin’s argument for the existence of molecules from his 1908 experimental determination of Avogadro’s number raises two questions considered in this article. One is historical: Why as late as 1908 should Perrin have thought it necessary to argue that molecules exist? The other, which takes up the bulk of this article, is philosophical: In view of the fact that his argument appears to assume the existence of molecules as a premise, how, if at all, can a charge of circularity (...) be avoided? I criticize attempted reconstructions of his argument by Salmon, Glymour, and hypothetico-deductivists. And I propose a probabilistic solution that avoids circularity. Finally, I consider whether Perrin’s reasoning, so construed, is an empirical argument for scientific realism. (shrink)

So far I have said nothing about the Principle of Verification, the most distinctive claim of the positivists. In the volume Carnap traces the development of his views from narrow to more liberalized versions of empiricism. During the 1920's, holding that the meaning of a statement is given by the conditions of its verification, and that a statement is meaningful if and only if it is in principle verifiable, he declared many theses of traditional metaphysics to be meaningless. In Der (...) Logische Aufbau der Welt he defended a phenomenalist thesis according to which cognitively meaningful statements could be translated into a language referring only to total moments of experience. Later he espoused physicalism, the claim that cognitively meaningful statements are translatable into statements concerning observable properties of physical things. In "Testability and Meaning", recognizing that statements about "theoretical" entities in science can never be completely translated into observational terms, Carnap liberalized his empiricism by requiring for cognitive meaning not translation into observational terms, but only the possibility of confirmation on the basis of observation. What I propose to consider here are Carnap's latest thoughts on these issues as expressed in his Introduction and Replies and in recent articles. (shrink)

Seven essays explore issues of scientific methodology in various episodes of science from Newtonian physics of the 17th and 18th century to quantum mechanics in the 20th. Addressed to scholars of the history and philosophy of science, but also accessible to general readers. Annotation copyright Book.

This volume brings together eleven essays by the distinguished philosopher of science, Peter Achinstein. The unifying theme is the nature of the philosophical problems surrounding the postulation of unobservable entities such as light waves, molecules, and electrons. How, if at all, is it possible to confirm scientific hypotheses about "unobservables"? Achinstein examines this question as it arose in actual scientific practice in three nineteenth-century episodes: the debate between particle and wave theorists of light, Maxwell's kinetic theory of (...) gases, and J.J. Thomson's discovery of the electron. The book contains three parts, each devoted to one of these topics, beginning with an essay presenting the historical background of the episode and an introduction to the philosophical issues. There is an illuminating evaluation of various scientific methodologies, including hypothetico-deductivism, inductivism, and the method of independent warrant which combines features of the first two. Achinstein assesses the philosophical validity of both nineteenth-century and modern answers to questions about unobservables, and presents and defends his own solutions. (shrink)

By reference to Maxwell's kinetic theory, one feature of hypothetico-deductivism is defended. A scientist need make no inference to a hypothesis when he first proposes it. He may have no reason at all for thinking it is true. Yet it may be worth considering. In developing his kinetic theory there were central assumptions Maxwell made (for example, that molecules are spherical, that they exert contact forces, and that their motion is linear) that he had no reason to believe true. In (...) this paper I develop a position that explains why they were worth considering, and that rejects the retroductive position that a hypothesis is worth considering when, if true, it would explain the observed data. (shrink)

During the first four decades of the nineteenth century a debate raged over the nature of light. Following proposals of Isaac Newton made early in the eighteenth century, many physicists accepted the theory that light is composed of tiny particles subject to mechanical forces (see newton). At the beginning of the nineteenth century Thomas Young and Augustin Fresnel revived a competing theory originally suggested by Christiaan Huygens in the seventeenth century, according to which light consists not of particles, but of (...) waves in a medium called the ether. In both cases theorists postulated entities ‐ particles and waves in an ether ‐ that could not be observed. Yet theorists on both sides gave arguments for the existence of these entities and the properties they ascribed to them. They did so on the basis of what they could observe. How was this possible? (shrink)

Theories of explanation are characterized as being either pragmatic or non-pragmatic, without a clear sense of what this is supposed to mean. The present paper offers a definition of a "pragmatic explanation-sentence", and in terms of this, of a "pragmatic theory of explanation". It is argued that van Fraassen's theory of explanation, despite claims to the contrary, is not genuinely pragmatic. By contrast, the author's own "illocutionary" theory is pragmatic. Attention is devoted particularly to sentences of the form "E is (...) a good explanation of q", which, it is urged, are pragmatic in a strong sense. In defense of this claim, and of the advantages of a pragmatic account generally, appeal is made to Rutherford's 1911 subatomic explanation of the results of his scattering experiments. Implications of a pragmatic theory are drawn for the debate between realists and anti-realists and absolutists and relativists. (shrink)

It is often said that singular causal statements express a relationship between one event and another or between a fact and an event. This is a very strong view, which has the following simple corollary: singular causal statements whose cause-term purports to refer to an event and whose effect-term purports to refer to an event express a relationship between an event and an event.Thus, both Davidson and Kim would claim that the singular causal Statement Socrates’ drinking hemlock at dusk caused (...) his death expresses a relationship between two events, referred to, respectively, by the expressions “Socrates’ drinking hemlock at dusk” and “his death.” For Kim, but not for Davidson, an event is analyzable as a thing's having a property at or during a time. The event of Socrates’ drinking hemlock at dusk consists of Socrates’ at a certain time having the property of drinking hemlock at dusk. I shall not here try to choose between their respective theories of events but will only note that both theorists would say that expresses a relationship between events however the latter are to be construed. (shrink)

Recent accounts of scientific method suggest that a model, or analogy, for an axiomatized theory is another theory, or postulate set, with an identical calculus. The present paper examines five central theses underlying this position. In the light of examples from physical science it seems necessary to distinguish between models and analogies and to recognize the need for important revisions in the position under study, especially in claims involving an emphasis on logical structure and similarity in form between theory and (...) analogy. While formal considerations are often relevant in the employment of an analogy they are neither as extensive as proponents of this viewpoint suggest, nor are they in most cases sufficient for allowing analogies to fulfill the roles imputed to them. Of major importance, and what these authors generally fail to consider, are physical similarities between analogue and theoretical object. Such similarities, which are characteristic in varying degrees of most analogies actually employed, play an important role in affording a better understanding of concepts in the theory and also in the development of the theoretical assumptions. (shrink)

This paper examines problems of order and periodicity which arise when the attempt is made to define a confirmation function for a language containing elementary number theory as applied to a universe in which the individuals are considered to be arranged in some fixed order. Certain plausible conditions of adequacy are stated for such a confirmation function. By the construction of certain types of predicates, it is proved, however, that these conditions of adequacy are violated by any confirmation function defined (...) for the type of language in question. Various possible solutions to these difficulties are explored and found to be inadequate. In particular, a proposal which stems from the suggestion to restrict a fundamental principle of confirmation to hypotheses containing only non-positional predicates is cited. This proposal, however, is shown to prevent confirmation functions from taking periodicities into account, and so is deemed unsatisfactory. A general theorem is proved to the effect that if non-positional predicates are taken to satisfy the conditions of adequacy which have been formulated, then no periodicity predicates whatsoever (i.e., predicates used in formulating hypotheses which foretell periodicities) can be subject to these conditions, on pain of contradiction. Yet it seems that periodicity predicates must be subject to these conditions of adequacy if a confirmation function is to recognize periodic occurrences. Thus, an impasse seems to be reached. In the final sections we consider the beginnings of one possible solution to these difficulties. Our proposal involves treating sets of individuals, rather than individuals themselves, as instances of an hypothesis which predicts a periodicity. On this basis we formulate new conditions of adequacy which are free from the previous difficulties and which will permit a confirmation function that satisfies them to take periodicities into account. (shrink)