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 ...

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)

An a priori thesis about evidence, defended by many, states that the only empirical fact that can affect the truth of an objective evidence claim of the form ‘e is evidence for h’ (or ‘e confirms h to degree r’) is the truth of e; all other considerations are a priori. By examining cases involving evidential flaws, I challange this claim and defend an empirical concept of evidence. In accordance with such a concept, whether, and the extent to which, e, (...) if true, confirms h is an empirical, not a priori, fact. (shrink)

According to a standard account of evidence, one piece of information is stronger evidence for an hypothesis than is another iff the probability of the hypothesis on the one is greater than it is on the other. This condition, I argue, is neither necessary nor sufficient because various factors can strengthen the evidence for an hypothesis without increasing (and even decreasing) its probability. Contrary to what probabilists claim, I show that this obtains even if a probability function can take these (...) evidential factors into account in ways they suggest and yield a unique probability value. Nor will the problem be solved by appealing to second-order probabilities. (shrink)

If the problem of induction were soluble, it should be solved inductively: by observing how scientists observe, etc. The fact is that scientific research is successful, and the real question is, will it be so in future? If there is a formula of induction by which success is achieved, then by this formula we can say, as long as it will be used science will succeed. If there is no formula it looks as if future success in scientific research is (...) most doubtful. Hence, a transcendental argument for induction goes, there is an inductive formula. Since, however, such a view of induction is rejected even by inductivists as naive, the argument collapses. Hence the question is, on what basis do we project the future success of science? My answer is that this future success is built into our social institutions and is partially institutionally safeguarded. (shrink)

Two theses figure centrally in work on the epistemology of disagreement: Equal Weight (‘EW’) and Uniqueness (‘U’). According to EW, you should give precisely as much weight to the attitude of a disagreeing epistemic peer as you give to your own attitude. U has it that, for any given proposition and total body of evidence, some doxastic attitude is the one the evidence makes rational (justifies) toward that proposition. Although EW has received considerable discussion, the case for U has not (...) been critically evaluated. Endorsing U, we argue, commits one to the highly controversial thesis that whatever fixes your rational attitudes can do so only by fixing what evidence you have. This commitment imposes a relatively demanding requirement on justified belief in U, one that we argue is not satisfied by what is currently the strongest available case for U, due to Roger White [2005]. Our challenge to U makes more trouble for its proponents than do the worries about U expressed by Gideon Rosen [2001] and Thomas Kelly [2010]. Moreover, if Kelly [2010] is correct in thinking that EW “carries with it a commitment to” U—a claim which we accept for reasons similar to Kelly’s but is beyond this paper’s scope (but see Ballantyne and Coffman [forthcoming])—then our challenge to U bears importantly on EW: to the extent that our challenge to U succeeds, EW also suffers. (shrink)

Sherrilyn Roush's Tracking Truth provides a sustained and ambitious development of the basic idea that knowledge is true belief that tracks the truth. In this essay, I provide a quick synopsis of Roush's book and offer a substantive discussion of her analysis of scientific evidence. Roush argues that, for e to serve as evidence for h, it should be easier to determine the truth value of e than it is to determine the truth value of h, an ideal she refers (...) to as 'leverage'. She defends a detailed method by which the value of p(h/e) is computed without 'direct' information about p(h) but only using evidence about the value of p(e), from which the value of p(h) is derived. She presents an example of how to use her leverage method, which I argue involves a certain critical mistake. I show how the leveraging method can be used in a way that is sound--I conclude with a few remarks about the importance of distinguishing clearly between prior and posterior probabilities. (shrink)

INTRODUCTION I should begin by warning the reader that many of the views presented in this book are decidedly unfashionable; the theory of probability I ...

Evidence is often taken to be foundational, in that while other propositions may be inferred from our evidence, evidence propositions are themselves not inferred from anything. I argue that this conception is false, since the non-inferential propositions on which beliefs are ultimately founded may be forgotten or undermined in the course of enquiry.

Rowbottom (2008) has recently challenged my definition of epistemic reasons for action and has offered an alternative account. In this paper, I argue that less than giving an 'alternative' definition, Rowbottom has offered an additional condition to my original account. I argue, further, that such an extra condition is unnecessary, i.e. that the arguments designed to motivate it do not go through.

In this paper I consider whether there can be such things as epistemic reasons for action. I consider three arguments to the contrary and argue that none are successful, being either somewhat question-begging or too strong by ruling out what most epistemologists think is a necessary feature of epistemic justification, namely the epistemic basing relation. I end by suggesting a "non-cognitivist" model of epistemic reasons that makes room for there being epistemic reasons for action and suggest that this model may (...) support moral realism. (shrink)

Many philosophers have claimed that evidence for a theory is better when multiple independent tests yield the same result, i.e., when experimental results are robust. Little has been said about the grounds on which such a claim rests, however. The present essay presents an analysis of the evidential value of robustness that rests on the fallibility of assumptions about the reliability of testing procedures and a distinction between the strength of evidence and the security of an evidence claim. Robustness can (...) enhance the security of an evidence claim either by providing what I call second-order evidence, or by providing back-up evidence for a hypothesis. (shrink)

Contemporary ways of understanding of science, especially in the philosophy of science, are beset by overly abstract and formal models of evidence. In such models, the only interesting feature of evidence is that it has a one-way ``support'' relation to hypotheses, theories, causal claims, etc. These models create a variety of practical and philosophical problems, one prominent example being the experimenter's regress. According to the experimenter's regress, good evidence is produced by good techniques, but which techniques are good is only (...) determined by whether they produce the evidence we expect. The best answer to this problem within the traditional approach relies on the concept of robust evidence, but this answer ultimately falls flat because it creates impossible requirements on good evidence. The problem can more easily be solved by rejecting abstract, formalistic models of evidence in favor of a model of inquiry which pays attention to the temporal complexity of the process of inquiry and the distinction between observational and experimental evidence. (shrink)

This article agrees with Philip Kitcher that we should aim for a well-ordered science, one that answers the right questions in the right ways. Crucial to this is to address questions of use: Which scientific account is right for which system in which circumstances? This is a difficult question: evidence that may support a scientific claim in one context may not support it in another. Drawing on examples in physics and other sciences, this article argues that work on the warrant (...) of theories in philosophy of science needs to change. Emphasis should move from the warrant of theories in the abstract to questions of evidence for use. (shrink)

The main appeal of the currently popular "bootstrap" account of confirmation developed by Clark Glymour is that it seems to provide an account of evidential relevance. This account has, however, had severe problems; and Glymour has revised his original account in an attempt to solve them. I argue that this attempt fails completely, and that any similar modifications must also fail. If the problems can be solved, it will only be by radical revisions which involve jettisoning bootstrapping's basic approach to (...) theories. Finally, I argue that there is little reason to think that even such drastic modifications will lead to a satisfactory account of relevance. (shrink)

Among Bayesian confirmation theorists, several quantitative measures of the degree to which an evidential proposition E confirms a hypothesis H have been proposed. According to one popular recent measure, s , the degree to which E confirms H is a function of the equation P(H|E) − P(H|~E). A consequence of s is that when we have two evidential propositions, E1 and E2, such that P(H|E1) = P(H|E2), and P(H|~E1) ≠ P(H|~E2), the confirmation afforded to H by E1 does not equal (...) the confirmation afforded to H by E2. I present several examples that demonstrate the unacceptability of this result, and conclude that we should reject s (and other measures that share this feature) as a measure of confirmation. (shrink)

The likelihood theory of evidence (LTE) says, roughly, that all the information relevant to the bearing of data on hypotheses (or models) is contained in the likelihoods. There exist counterexamples in which one can tell which of two hypotheses is true from the full data, but not from the likelihoods alone. These examples suggest that some forms of scientific reasoning, such as the consilience of inductions (Whewell, 1858. In Novum organon renovatum (Part II of the 3rd ed.). The philosophy of (...) the inductive sciences. London: Cass, 1967), cannot be represented within Bayesian and Likelihoodist philosophies of science. (shrink)

, Peter Achinstein argues against the long-standing claim that ‘evidence’ is ambiguous in possessing a sense of confirming evidence and a sense of supporting evidence. He argues that explications of supporting evidence will necessarily violate his contentions that evidence is a discontinuous ‘threshold concept’ and that any philosophical account of supporting evidence will be too weak to be useful to working scientists. But an account of supporting evidence may be formulated which includes Achinstein's notion of epistemic thresholds that finds examples (...) in Achinstein's own historical case studies. Thresholds and the denial of ambiguity Achinstein's new account of confirming evidence Achinstein's argument against the ‘ambiguity response’ A threshold-based approach for restoring the ambiguity Maxwell and ‘a subject of rational curiosity’ Bohr and ‘future development of our understanding’ Perrin and the edge of reasonable belief Restoring ambiguity. (shrink)

S CIENTISTS often claim that an experiment or observation tests certain hypotheses within a complex theory but not others. Relativity theorists, for example, are unanimous in the judgment that measurements of the gravitational red shift do not test the field equations of general relativity; psychoanalysts sometimes complain that experimental tests of Freudian theory are at best tests of rather peripheral hypotheses; astronomers do not regard observations of the positions of a single planet as a test of Kepler's third law, even (...) though those observations may test Kepler's first and second laws. Observations are regarded as relevant to some hypotheses in a theory but not relevant to others in that same theory. There is another kind of scientific judgment that may or may not be related to such judgments of relevance: determinations of the accuracy of the predictions of some theories are not held to provide tests of those theories, or, at least, positive results are not held to support or confirm the theories in question. There are, for example, special relativistic theories of gravity that predict the same phenomena as does general relativity, yet the theories are regarded as.. (shrink)

The first part of the paper distinguishes between a real past which has nothing to do with historical events and an historical past made up of hypothetical events introduced for the purpose of explaining historical evidence. Attention is next paid to those so-called ancillary historical disciplines which study historical evidence, and it is noted that the historical event is brought in to explain the particular constellation of different kinds of historical evidence which are judged to belong together. The problem of (...) explaining events is then taken up, and an attempt is made to defend the view that such explanation must presuppose general laws. And this is followed by a discussion, partly speculative, of social-historical laws. The final section of the paper tries to argue that the subjective intentions of individuals are irrelevant to historical explanation. (shrink)

The basic understanding which underlies scientific evidence - ideas such as the structure of experiments, causality, repeatability, validity and reliability- is not straightforward. But these ideas are needed to judge evidence in school science, in physics or chemistry or biology or psychology, in undergraduate science, and in understanding everyday issues to do with science. It is essential to be able to be critical of scientific evidence. The authors clearly set out the principles of investigation so that the reader will be (...) confident in questioning the experts, making an informed choice or arriving at in informed opinion. The book is intended for a wide range of readers including those who want to: } collect their own evidence } be able to question and judge a wide range of science-based issues that we come across in the press or other media in everyday life } teach others how to understand evidence. This book has been developed from the authors' work with first year undergraduates in a combined science course and in primary teacher training for science specialists. It is suitable for students training as primary science specialists, and also for 'A' level and first-year undergraduates in science and science-related subjects. (shrink)

Michael Devitt ([2006a], [2006b]) argues that, insofar as linguists possess better theories about language than non-linguists, their linguistic intuitions are more reliable. ( Culbertson and Gross [2009] ) presented empirical evidence contrary to this claim. Devitt ([2010]) replies that, in part because we overemphasize the distinction between acceptability and grammaticality, we misunderstand linguists’ claims, fall into inconsistency, and fail to see how our empirical results can be squared with his position. We reply in this note. Inter alia we argue that (...) Devitt's focus on grammaticality intuitions, rather than acceptability intuitions, distances his discussion from actual linguistic practice. We close by questioning a demand that drives his discussion—viz., that, for linguistic intuitions to supply evidence for linguistic theorizing, a better account of why they are evidence is required. (shrink)

Methodology Introduction This book is about scientific knowledge, particularly the concept of evidence. Its purpose is to explore scientific methodology in ...

This paper rejects a traditional epistemic interpretation of conditional probability. Suppose some chance process produces outcomes X, Y,..., with probabilities P(X), P(Y),... If later observation reveals that outcome Y has in fact been achieved, then the probability of outcome X cannot normally be revised to P(X|Y) ['P&Y)/P(Y)]. This can only be done in exceptional circumstances - when more than just knowledge of Y-ness has been attained. The primary reason for this is that the weight of a piece of evidence varies (...) with the means by which it is provided, so knowledge of Y-ness does not have uniform impact on the probability of X. A better updating of the probability of X is provided by P(X|Y*), where Y* is not an outcome of the chance process being observed, but the sentence 'the outcome Y has been observed', an 'outcome' of the subsequent observation process. This alternative formula is widely endorsed in practice, but not well recognized in theory, where the oversight has generated some unsatisfactory consequences. (shrink)

Responses to John Broome and John Brunero.

In this paper, we argue for a particular informative and unified analysis of normative reasons. According to this analysis, a fact F is a reason to act in a certain way just in case it is evidence that one ought to act in that way. Similarly, F is a reason to believe a certain proposition just in case it is evidence for the truth of this proposition. Putting the relatively uncontroversial claim about reasons for belief to one side, we present (...) several arguments in favor of our analysis of reasons for action. We then turn to consider a series of objections to the analysis. We conclude that there are good reasons to accept the analysis and that the objections do not succeed. (shrink)

I defend the first premise of William Rowe’s well-known arguments from evil against influential criticisms due to William Alston. I next suggest that the central inference in Rowe’s arguments is best understood to move from the claim that we have an absence of evidence of a satisfactory theodicy to the claim that we have evidence of absence of such a theodicy. I endorse the view which holds that this move succeeds only if it is reasonable to believe that (roughly) if (...) there were such a theodicy, we would probably know it. After conceding that there may be modest prima facie support for this latter claim via the Principle of Credulity, I consider and reject four more ambitious arguments in its favour. I conclude that this necessary condition on Rowe’s crucial inference has not been shown to be satisfied. (shrink)

Since Ramsey, much discussion of the relation between probability and belief has taken for granted that there are degrees of belief, i.e., that there is a real-valued function, B, that characterizes the degree of belief that an agent has in each statement of his language. It is then supposed that B is a probability. It is then often supposed that as the agent accumulates evidence, this function should be updated by conditioning: BE(·) should be B(·E)/B(E). Probability is also important in (...) classical statistics, where it is generally supposed that probabilities are frequencies, and that inference proceeds by controlling error and not by conditioning. I will focus on the tension between these two approaches to probability, and in the main part of the paper show where and when Bayesian conditioning conflicts with error based statistics and how to resolve these conflicts. (shrink)

In a series of recent papers Stephen Kearns and Daniel Star argue that normative reasons to ϕ simply are evidence that one ought to ϕ, and suggest that “evidence” in this context is best understood in standard Bayesian terms. I contest this suggestion.

Introduction -- Epistemic value -- Reasons for belief (I) -- Reasons for belief (II) -- Assertion -- Action -- Justification.

According to Williamson, your evidence consists of all and only what you know (E = K). According to his critics, it doesn’t. While E = K calls for revision, the revisions it calls for are minor. E = K gets this much right. Only true propositions can constitute evidence and anything you know non-inferentially is part of your evidence. In this paper, I defend these two theses about evidence and its possession from Williamson’s critics who think we should break more (...) radically from E = K. (shrink)

The subject of this essay is the dependence of evidential relations on background beliefs and assumptions. In Part I, two ways in which the relation between evidence and hypothesis is dependent on such assumptions are discussed and it is shown how in the context of appropriately differing background beliefs what is identifiable as the same state of affairs can be taken as evidence for conflicting hypotheses. The dependence of evidential relations on background beliefs is illustrated by discussions of the Michelson-Morley (...) experiment and the discovery of oxygen. In Part II, Hempel's analysis of confirmation and the contrasting model of theory acceptance provided by philosophers such as Kuhn and Feyerabend are discussed. It is argued that both are inadequate (on different grounds) and the problems addressed by each are shown to be more satisfactorily approached by means of the analysis developed in Part I. In Part III, it is argued that if there are objective criteria for deciding between competing theories, these cannot be simply that one theory has greater evidential support than another. Finally, some further methodological questions arising from the analysis are mentioned. (shrink)

While many philosophers of science have accorded special evidential significance to tests whose results are "novel facts", there continues to be disagreement over both the definition of novelty and why it should matter. The view of novelty favored by Giere, Lakatos, Worrall and many others is that of use-novelty: An accordance between evidence e and hypothesis h provides a genuine test of h only if e is not used in h's construction. I argue that what lies behind the intuition that (...) novelty matters is the deeper intuition that severe tests matter. I set out a criterion of severity akin to the notion of a test's power in Neyman-Pearson statistics. I argue that tests which are use-novel may fail to be severe, and tests that are severe may fail to be use-novel. I discuss the 1919 eclipse data as a severe test of Einstein's law of gravity. (shrink)

The phenomenon of mutual support presents a specific challenge to the foundationalist epistemologist: Is it possible to model mutual support accurately without using circles of evidential support? We argue that the appearance of loops of support arises from a failure to distinguish different synchronic lines of evidential force. The ban on loops should be clarified to exclude loops within any such line, and basing should be understood as taking place within lines of evidence. Uncertain propositions involved in mutual support relations (...) are conduits to each other of independent evidence originating ultimately in the foundations. We examine several putative examples of benign loops of support and show that, given the distinctions noted, they can be accurately modeled in a foundationalist fashion. We define an evidential “tangle,” a relation among three propositions that appears to require a loop for modeling, and prove that all such tangles are trivial in a sense that precludes modeling them with an evidential circle. (shrink)

The fundamental constants that are involved in the laws of physics which describe our universe are finely tuned for life, in the sense that if some of the constants had slightly different values life could not exist. Some people hold that this provides evidence for the existence of God. I will present a probabilistic version of this fine-tuning argument which is stronger than all other versions in the literature. Nevertheless, I will show that one can have reasonable opinions such that (...) the fine-tuning argument doesn't lead to an increase in one's probability for the existence of God. The fine-tuning argument Objective versus subjective probability Observational selection effects The problem of old evidence Against the fine-tuning argument Many universes. (shrink)

Evidence-based approaches to policy-making are growing in popularity. A generally embraced view is that with the appropriate evidence at hand, decision and policy making will be optimal, legitimate and publicly accountable. In practice, however, evidence-based policy making is constrained by a variety of problems of evidence. Some of these problems will be explored in this article, in the context of the debates on evidence from which they originate. It is argued that the source of much disagreement might be a failure (...) to addressing crucial philosophical assumptions that inform, often silently, these debates. Three controversial questions will be raised which appear central to some of the challenges faced by evidence-based policy making: firstly, how do certain types of facts candidate themselves as evidence; secondly, how do we decide what evidence we have, and how much of it; and thirdly, can we combine evidence. In addressing these questions it will be shown how a philosophically informed debate might prove instrumental in clarifying and settling practical difficulties. (shrink)

The Variety of Evidence Thesis (VET) says that (ceteris paribus) the more diverse (or varied) of two bodies of evidence is the more confirmatory of a hypothesis H. Two recent types of Bayesian explication of VET account for the intuitive force of VET by defining variety as some function of the probabilities of the propositions which collectively constitute a body of evidence. I show that these two accounts of VET are not tracking a meaningful property of bodies of evidence, but (...) rather are tracking artifacts of how those bodies of evidence are described. According to each account, whether a body of evidence is more varied than another depends on how the bodies are split into parts. Furthermore, for each type of account there exists a way to redescribe the total evidence such that any two totalities are equally varied. ‡I would like to thank Elliott Sober for comments on multiple drafts of this paper, and Malcolm Forster, John Koolage, and Joel Velasco for comments on a verbal delivery. †To contact the author, please write to: Department of Philosophy, University of Wisconsin-Madison, 5185 Helen C. White Hall, 600 North Park Street, Madison, WI 53706; e-mail: gmnovack@wisc.edu. (shrink)

Popper's paradox of ideal evidence has long been viewed as a telling criticism of Keynes's logical theory of probability and its associated concept of the weight of argument. This paper shows that a simple addition to Keynes's definitions of irrelevance enables his theory to elude the paradox with ease. The modified definition draws on ideas already present in Keynes's Treatise on Probability (1973). As a consequence, relevant evidence and the weight of argument may increase, even when new evidence leaves the (...) probability unaltered. (shrink)

Holistic claims about evidence are a commonplace inthe philosophy of science; holistic claims aboutmeaning are a commonplace in the philosophy oflanguage. W. V. Quine has advocated both types ofholism, and argued for an intimate link between thetwo. Semantic holism may be inferred from theconjunction of confirmation holism andverificationism, he maintains. But in their recentbook Holism: a Shopper's Guide, Jerry Fodor andErnest Lepore (1992) claim that this inference isfallacious. In what follows, I defend Quine's argumentfor semantic holism from Fodor and Lepore'smulti-pronged (...) attack. (shrink)

This paper attempts to argue for the theory-ladenness of evidence. It does so by employing and analysing an episode from the history of eighteenth century chemistry. It delineates attempts by Joseph Priestley and Antoine Lavoisier to construct entirely different kinds of evidence for and against a particular hypothesis from a set of agreed upon observations or (raw) data. Based on an augmented version of a distinction, drawn by J. Bogen and J. Woodward, between data and phenomena it is shown that (...) the role of theoretical auxiliary assumptions is very important in constructing evidence for (or against) a theory from observation or (raw) data. In revolutionary situations, rival groups hold radically different theories and theoretical auxiliary assumptions. These are employed to construct very different evidence from the agreed upon set of observations or (raw) data. Hence, theory resolution becomes difficult. It is argued that evidence construction is a multi-layered exercise and can be disputed at any level. What counts as unproblematic observation or (raw) data at one level may become problematic at another level. The contingency of these constructions and the (un)problematic nature of evidence are shown to be partially dependent upon the scientific knowledge that the scientific community possesses. (shrink)

Taking its clues from Popperian philosophy of science, cladistics adopted a number of assumptions of the empiricist tradition. These include the identification of a dichotomy between observation reports and theoretical statements and its subsequent abandonment on the basis of the insight that all observation reports are theory-laden. The neglect of the ‘context of discovery’, which is the step of theory (hypothesis) generation. The emphasis on coherentism in the ‘context of justification’, which is the step of evaluation of the relative merits (...) of alternative theories. The appeal to a total evidence approach in phylogenetic inference. And finally, a silence about causation, which results in an instrumentalist approach to phylogeny reconstruction. This paper explores how these empiricist assumptions are embedded in phylogenetic systematics, and why these assumptions are problematic for cladists (or any taxonomists). (shrink)

This paper responds to Achinstein’s criticism of the thesis that the only empirical fact that can affect the truth of an objective evidence claim such as ‘e is evidence for h’ (or ‘e confirms h to degree r’) is the truth of e. It shows that cases involving evidential flaws, which form the basis for Achinstein’s objections to the thesis, can satisfactorily be accounted for by appeal to changes in background information and working assumptions. The paper also argues that the (...) a priori and empirical accounts of evidence are on a par when we consider scientific practice, but that a study of artificial intelligence might serve to differentiate them. (shrink)

L. Jonathan Cohen has written a number of important books and articles in which he argues that mathematical probability provides a poor model of much of what paradigmatically passes for sound reasoning, whether this be in the sciences, in common discourse, or in the law. In his book, The Probable and the Provable, Cohen elaborates six paradoxes faced by advocates of mathematical probability (PM) when treating issues of evidence as they would arise in a court of law. He argues that (...) his system of inductive probability (PI) satisfactorily handles the issues that proved paradoxical for mathematical probability, and consequently PI deserves to be thought of as an important standard of rational thinking. I argue that a careful look at each of the alleged paradoxes shows that there is no conflict between mathematical probability and the law, except when for reasons of policy we opt for values in addition to accuracy maximization. Recognizing the role of such policies provides no basis for questioning the adequacy of PM. The significance of this critical treatment of Cohen's work is that those interested in revising the laws of evidence to allow for more explicitly mathematical approaches ought to feel that such revisions will not violate the spirit of forensic rationality. (shrink)

Entitlement is conceived as a kind of positive epistemic status, attaching to certain propositions, that involves no cognitive or intellectual accomplishment on the part of the beneficiary - a status that is in place by default. In this paper I will argue that the notion of entitlement - or something very like it - falls out of an idea that may at first blush seem rather disparate: that the evidential support relation can be understood as a kind of variably strict (...) conditional (in the sense of Lewis 1973). Lewis provided a general recipe for deriving what he termed inner modalities from any variably strict conditional governed by a logic meeting certain constraints. On my proposal, entitlement need be nothing more exotic than the inner necessity associated with evidential support. Understanding entitlement in this way helps to answer some common concerns?in particular, the concern that entitlement could only be a pragmatic, and not genuinely epistemic, status. (shrink)

There are a number of apparent parallels between belief in God and belief in the existence of an external world beyond our experiences. Both beliefs would seem to condition one's overall view of reality and one's place within it – and yet it is difficult to see how either can be defended. Neither belief is likely to receive a purely a priori defence and any empirical evidence that one cites either in favour of the existence of God or the existence (...) of the external world would seem to blatantly beg the question against a doubter. I will explore just how far this parallel can be pushed by examining some strategies for resisting external world scepticism1. (shrink)

To infer the state of a cause from the states of its effects, independent lines of evidence are preferable to dependent ones. This familiar idea is here investigated, the goal being to identify its presuppositions. Connections are drawn with Reichenbach's (1956) and Salmon's (1984) discussions of the principle of the common cause.

I contrast two modes of error-elimination relevant to evaluating evidence in accounts that emphasize frequentist reliability. The contrast corresponds to that between the use of of a reliable inference procedure and the critical scrutiny of a procedure with regard to its reliability, in light of what is and is not known about the setting in which the procedure is used. I propose a notion of security as a category of evidential assessment for the latter. In statistical settings, robustness theory and (...) misspecification testing exemplify two distinct strategies for securing statistical inferences. (shrink)

From the perspective of Mayo’s error statistical theory of evidence, I explore problems and prospects for an account of the objectivity of scientific evidence. A recent proposal by Peter Achinstein provides the starting point. I consider a challenge to this proposal arising from the role of agents in carrying out the testing procedures that are central to the error statistical theory. Achinstein’s objective concept of unrelativized potential evidence initially resolves these difficulties, only to give way to a deeper incompatibility between (...) Achinstein’s conception of objectivity of reasons to believe and the error statistical theory of evidence. I propose an alternative account of objectivity of reasons that is compatible with the error statistical theory. (shrink)

: Evidence claims depend on fallible assumptions. Three strategies for making true evidence claims in spite of this fallibility are strengthening the support for those assumptions, weakening conclusions, and using multiple independent tests to produce robust evidence. Reliability itself, understood in frequentist terms, does not explain the usefulness of all three strategies; robustness, in particular, sometimes functions in a way that is not well-characterized in terms of reliability. I argue that, in addition to reliability, the security of evidence claims is (...) of epistemic value, where an evidence claim is secure relative to an epistemic situation if it remains true in all scenarios that are epistemically possible relative to that epistemic situation. (shrink)

Many philosophers have claimed that evidence for a theory is better when multiple independent tests yield the same result, i.e., when experimental results are robust. Little has been said about the grounds on which such a claim rests, however. The present essay presents an analysis of the evidential value of robustness that rests on the fallibility of assumptions about the reliability of testing procedures and a distinction between the strength of evidence and the security of an evidence claim. Robustness can (...) enhance the security of an evidence claim either by providing what I call second-order evidence, or by providing back-up evidence for a hypothesis. (shrink)

Bealer, G. (1998). “Intuition and the Autonomy of Philosophy,” in M. DePaul & W. Ramsey, eds., Rethinking Intuition: The Psychology of Intuition and Its Role in Philosophical Inquiry, Lanham, MD: Rowman & Littlefield.

Epistemic reasons are mental states. They are not propositions or non-mental facts. The discussion proceeds as follows. Section 1 introduces the topic. Section 2 gives two concrete examples of how our topic directly affects the internalism/externalism debate in normative epistemology. Section 3 responds to an argument against the view that reasons are mental states. Section 4 presents two problems for the view that reasons are propositions. Section 5 presents two problems for the view that reasons are non-mental facts. Section 6 (...) argues that reasons are mental states. Section 7 responds to objections. (shrink)

In this article I probe the consequences and limits of the underdetermination thesis and the empirical equivalence thesis, using Laudan and Leplin's fecund article as a springboard. Although a realist at heart, my primary intention is not to undermine the anti-realist arguments but rather to try to precisify the challenge the realist, and more generally the participant in the scientific realism debate, faces.

A stalwart view in the philosophy of science holds that, even when broadly construed so as to include theoretical auxiliaries, theories cannot make direct contact with observations. This view owes much to Bogen and Woodward’s (1988) influential distinction between data and phenomena. According to them, data are typically the kind of things that are observable or measurable like "bubble chamber photographs, patterns of discharge in electronic particle detectors and records of reaction times and error rates in various psychological experiments" (p. (...) 306). Phenomena are physical processes that are typically unobservable. Examples of the latter category include "weak neutral currents, the decay of the proton, and chunking and recency effects in human memory" (ibid.). Theories, in Bogen and Woodward’s view, are utilised to systematically explain, infer and predict phenomena, not data (pp. 305-306). The relationship between theories and data is rather indirect. Data count as evidence for phenomena and the latter in turn count as evidence for theories. This view is becoming increasingly influential (e.g. Prajit K. Basu (2003), Stathis Psillos (2004) and Mauricio Suárez (2005)). In this paper I argue contrary to this view that in various significant and well-known cases theories do make direct contact with the help of suitable auxiliaries. (shrink)

In a recent paper James Bogen and James Woodward denounce a set of views on confirmation that they collectively brand ‘IRS’. The supporters of these views cast confirmation in terms of Inferential Relations between observational and theoretical Sentences. Against IRS accounts of confirmation, Bogen and Woodward unveil two main objections: (a) inferential relations are not necessary to model confirmation relations since many data are neither in sentential form nor can they be put in such a form and (b) inferential relations (...) are not sufficient to model confirmation relations because the former cannot capture evidentially relevant factors about the detection processes and instruments that generate the data. In this paper I have a two-fold aim: (i) to show that Bogen and Woodward fail to provide compelling grounds for the rejection of IRS models and (ii) to highlight some of the models’ neglected merits. (shrink)

Recent work in artificial intelligence has increasingly turned to argumentation as a rich, interdisciplinary area of research that can provide new methods related to evidence and reasoning in the area of law. Douglas Walton provides an introduction to basic concepts, tools and methods in argumentation theory and artificial intelligence as applied to the analysis and evaluation of witness testimony. He shows how witness testimony is by its nature inherently fallible and sometimes subject to disastrous failures. At the same time such (...) testimony can provide evidence that is not only necessary but inherently reasonable for logically guiding legal experts to accept or reject a claim. Walton shows how to overcome the traditional disdain for witness testimony as a type of evidence shown by logical positivists, and the views of trial sceptics who doubt that trial rules deal with witness testimony in a way that yields a rational decision-making process. (shrink)

A common methodological adage holds that diverse evidence better confirms a hypothesis than does the same amount of similar evidence. Proponents of Bayesian approaches to scientific reasoning such as Horwich, Howson and Urbach, and Earman claim to offer both a precise rendering of this maxim in probabilistic terms and an explanation of why the maxim should be part of the methodological canon of good science. This paper contends that these claims are mistaken and that, at best, Bayesian accounts of diverse (...) evidence are crucially incomplete. This failure should lend renewed force to a long-neglected global worry about Bayesian approaches. (shrink)

A rational person doesn’t believe just anything. There are limits on what it is rational to believe. How wide are these limits? That’s the main question that interests me here. But a secondary question immediately arises: What factors impose these limits? A first stab is to say that one’s evidence determines what it is epistemically permissible for one to believe. Many will claim that there are further, non-evidentiary factors relevant to the epistemic rationality of belief. I will be ignoring the (...) details of alternative answers in order to focus on the question of what kind of rational constraints one’s evidence puts on belief. Our main question concerns how far epistemic permission and obligation can come apart.1 Suppose I am epistemically permitted to believe P, i.e., it would not be irrational for me to believe it. Am I thereby obliged to believe P, or are other options rationally available to me?2 Might I be equally rational in remaining agnostic about P, or even believing not-P? Or could even a slightly stronger or weaker degree of confidence be just as reasonable? (shrink)

Background: The experimental method to acquire knowledge about efficacy and efficiency of medical procedures is well established in evidence-based medicine. A method to attain evidence about the significance of diseases and interventions from the patients' perspectives taking into account their right to self-determination about their lives and bodies has however not been sufficiently characterized.Design: Identification of a method to acquire evidence about the clinical significance of disease and therapeutic options from the patients' perspectives.Arguments: Communication between patient and physician is analyzed (...) as the method to attain evidence about what is at stake for individual patients in disease and therapy. It is the method that enables physicians to directly take into account patients' disease experiences and their aims regarding treatments. These patients' perspectives in turn determine the clinical significance of diagnoses and therapeutic options, if patient-autonomy is taken seriously.Conclusions: A full account of evidence-based medicine needs to include experimentation and communication between physician and patient as equally important methods to attain evidence necessary to practice patient-oriented medicine. The communicative method is especially important for primary physicians as they direct patients within the medical system to have their medical problems most effectively and efficiently addressed. (shrink)

Evidence-based medicine has beendefined as the conscientious and judicious useof current best evidence in making clinicaldecisions. This paper will attempt to explicatethe terms ``conscientious'''' and ``judicious''''within the evidence-based medicine definition.It will be argued that ``conscientious'''' and``judicious'''' represent virtue terms derived fromvirtue ethics and virtue epistemology. Theidentification of explicit virtue components inthe definition and therefore conception ofevidence-based medicine presents an importantstarting point in the connection between virtuetheories and medicine itself. In addition, aunification of virtue theories andevidence-based medicine will illustrate theneed for (...) future research in order to combinethe fields of virtue-based approaches andclinical practice. (shrink)