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)

There are two reasons, I claim, scientists do and should ignore standard philosophical theories of objective evidence: (1) Such theories propose concepts that are far too weak to give scientists what they want from evidence, viz., a good reason to believe a hypothesis; and (2) They provide concepts that make the evidential relationship a priori, whereas typically establishing an evidential claim requires empirical investigation.

In this article I have two primary goals. First, I present two recent views on the distinction between knowledge-that and knowledge-how (Stanley and Williamson, The Journal of Philosophy 98(8):411–444, 2001; Hetherington, Epistemology futures, 2006). I contend that neither of these provides conclusive arguments against the distinction. Second, I discuss studies from neuroscience and experimental psychology that relate to this distinction. Having examined these studies, I then defend a third view that explains certain relevant data from these studies by positing the (...) double dissociation of knowledge-that and knowledge-how and that is also able to do explanatory work elsewhere. (shrink)

Original and penetrating, this book investigates of the notion of inference from signs, which played a central role in ancient philosophical and scientific method. It examines an important chapter in ancient epistemology: the debates about the nature of evidence and of the inferences based on it--or signs and sign-inferences as they were called in antiquity. As the first comprehensive treatment of this topic, it fills an important gap in the histories of science and philosophy.

Throughout his work on the rationality of epistemic dependence, John Hardwig makes the striking observation that he believes many things for which he possesses no evidence (1985, 335; 1991, 693; 1994, 83). While he could imagine collecting for himself the relevant evidence for some of his beliefs, the vastness of the world and constraints of time and individual intellect thwart his ability to gather for himself the evidence for all his beliefs. So for many things he believes what others tell (...) him, as we all do. Epistemic dependence is the responsible choice, he argues, because he can be reasonably sure that those on whom he depends know more about the subject than he does. Epistemic dependence on experts is a smarter bet than epistemic autonomy: after all, Hardwig reasons, “if I were to pursue epistemic autonomy across the board, I would succeed in holding relatively uninformed, unreliable, crude, untested, and therefore irrational beliefs” (1985, 340) [...] In this paper I argue against what I call Hardwig’s no-evidence thesis: that knowledge and belief based on testimony are knowledge and belief for which the knower possesses no evidence. Against the no-evidence thesis, I propose we recognize that layperson B’s good reason to believe that expert A has good reason to believe proposition p constitutes evidence for B for p. I argue that the reasons Hardwig gives for the no-evidence thesis are inconclusive at best; at worst the no-evidence thesis coupled with his recognition of expert interdependence exposes him to recent criticisms by Stella Gaon and Stephen Norris. By rejecting the no-evidence thesis, we can recognize with Hardwig the importance of expert epistemic interdependence while avoiding the paradoxical implications of his position. (shrink)

According to some philosophers who accept a propositional conception of evidence, someone's evidence includes a proposition only if it is true. I argue against this thesis by appealing to the possibility of knowledge from falsehood.

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. CiteULike Connotea Del.icio.us What's this? (shrink)

This paper contains replies to comments on the author's paper "A Priori Knowledge and the Scope of Philosophy." Several points in the argument of that paper are given further clarification: the notion of our standard justificatory procedure, the notion of a basic source of evidence, and the doctrine of modal reliabilism. The reliability of intuition is then defended against Lycan's skepticism and a response is given to Lycan's claim that the scope of a priori knowledge does not include philosophically central (...) topics such as the nature of consciousness. Next a counterfactual account of intuitions proposed by Sosa is criticized. Finally, in response to certain questions raised by Sosa, the explanation of the evidential status of intuition offered in the original paper receives further elaboration. (shrink)

The topic of a priori knowledge is approached through the theory of evidence. A shortcoming in traditional formulations of moderate rationalism and moderate empiricism is that they fail to explain why rational intuition and phenomenal experience count as basic sources of evidence. This explanatory gap is filled by modal reliabilism -- the theory that there is a qualified modal tie between basic sources of evidence and the truth. This tie to the truth is then explained by the theory of concept (...) possession: this tie is a consequence of what, by definition, it is to possess (i.e., to understand) one’s concepts. A corollary of the overall account is that the a priori disciplines (logic, mathematics, philosophy) can be largely autonomous from the empirical sciences. (shrink)

Scientific essentialism is the view that some necessities (e.g., water = H2O) can be known only with the aid of empirical science. The thesis of the paper is that scientific essentialism does not extend to the central questions of philosophy and that these questions can be answered a priori. The argument is that the evidence required for the defense of scientific essentialism (e.g., twin earth intuitions) is reliable only if the intuitions required by philosophy to answer its central questions is (...) also reliable. Included is an outline of a modal reliabilist theory of basic evidence and a concept-possession account of the reliability of a priori intuition. (shrink)

It is no secret that scientists argue. They argue about theories. But even more, they argue about the evidence for theories. Is the evidence itself trustworthy? This is a bit surprising from the perspective of traditional empiricist accounts of scientific methodology according to which the evidence for scientific theories stems from observation, especially observation with the naked eye. These accounts portray the testing of scientific theories as a matter of comparing the predictions of the theory with the data generated by (...) these observations, which are taken to provide an objective link to reality. (shrink)

In this highly accessible book eight distinguished experts from a wide range of disciplines consider the nature and use of evidence in the modern world.

The first obstacle that confronts the student of induction is that of defining the subject matter. One initial point is to note that much of the relevant subject matter goes under the description ‘the theory of confirmation’. The distinction is primarily that the study of induction concerns inference, i.e. cases where one takes the conclusion to be established by the evidence, whereas confirmation concerns the weight of evidence, which one may take to be something like the credibility of a hypothesis (...) in the light of the evidence. Discussions of confirmation often concern incremental confirmation, i.e. cases where the evidence is taken to increase the credibility of some hypothesis, even if not sufficiently to warrant inferring the truth of that hypothesis. However, some uses of ‘confirmation’ clearly refer to absolute confirmation, cases where the credibility of the hypothesis in the light of the evidence exceeds some (high) threshold. One may ask whether inductive inference corresponds to the case of absolute confirmation for some suitable threshold. I shall discuss inference and confirmation together, though it should be noted that some approaches eschew inference altogether. For example, the Bayesian takes scientific reasoning to be a matter of adjusting credences in propositions in the light of evidence, and says nothing about unqualified belief in a proposition. However, if we are interested in inductive knowledge then we must consider inference, since only then do we have a detached proposition that is the possible content of a mental state of knowing. A more pressing question concerns which inferences (or allegedly confirmatory relations) should be classed as inductive. A natural and straightforward approach is to define induction as encompassing any form of reasoning that extrapolates from one population to another, usually from a sample of a population to the whole population. For example, one might note that all observations of the position of some planet fall on an ellipse that has the Sun at one of its foci; from this one concludes that all the positions that planet takes fall on this ellipse (i.e.. (shrink)

I present an argument that encapsulates the view that theory is underdetermined by evidence. I show that if we accept Williamson's equation of evidence and knowledge, then this argument is question-begging. I examine ways of defenders of underdetermination may avoid this criticism. I also relate this argument and my critique to van Fraassen's constructive empiricism.

The usual, comparative, conception of Inference to the Best Explanation (IBE) takes it to be ampliative. In this paper I propose a conception of IBE (‘Holmesian inference’) that takes it to be a species of eliminative induction and hence not ampliative. This avoids several problems for comparative IBE (e.g. how could it be reliable enough to generate knowledge?). My account of Holmesian inference raises the suspicion that it could never be applied, on the grounds that scientific hypotheses are inevitably underdetermined (...) by the evidence (i.e. are inevitably ampliative). I argue that this concern may be resisted by acknowledging, as Timothy Williamson has shown, that all knowledge is evidence. This suggests an approach to resisting scepticism different from those (e.g. the reliabilist approach) that embrace fallibilism. (shrink)

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.

What is the nature of the evidence provided by thought experiments in philosophy? For instance, what evidence is provided by the Gettier thought experiment against the JTB theory of knowledge? According to one view, it provides as evidence only a certain psychological proposition, e.g. that it seems to one that the subject in the Gettier case lacks knowledge. On an alternative, nonpsychological view, the Gettier thought experiment provides as evidence the nonpsychological proposition that the subject in the Gettier case lacks (...) knowledge (e.g., Williamson 2007). Given the centrality of thought experiments to philosophical enquiry, the correct account of thought experiment evidence is important for understanding the nature of philosophical methodology. Further, Williamson argues that a misguided adherence to the psychological view of thought experiment evidence encourages scepticism about philosophy since it opens a gap between our evidence and the nonpsychological subject matter of philosophy. The main aim of this paper is to defend the psychological view against recent objections. In particular, I argue that even if thought experiment evidence is psychological, it can still provide justification for non-psychological claims which are the subject matter of philosophy. (shrink)

How can philosophy of science be of more practical use? One thing we can do is provide practicable advice about how to determine when one empirical claim is relevant to the truth of another; i.e., about evidential relevance . This matters especially for evidence-based policy, where advice is thin—and misleading—about how to tell what counts as evidence for policy effectiveness. This paper argues that good efficacy results (as in randomized controlled trials), which are all the rage now, are only a (...) very small part of the story. To tell what facts are relevant for judging policy effectiveness, we need to construct causal scenarios about will happen when the policy is implemented. (shrink)

Joshua Thurow offers a defence of the claim that if a belief is defeasible by non-experiential evidence then it is defeasible by experiential evidence. He responds to an objection which I make against this claim, and offers two arguments in support of his own position. I show that Thurow's response misconstrues my objection, and that his supporting arguments fall short of their goal.

How much should your confidence in your beliefs be shaken when you learn that others – perhaps 'epistemic peers' who seem as well-qualified as you are – hold beliefs contrary to yours? This article describes motivations that push different philosophers towards opposite answers to this question. It identifies a key theoretical principle that divides current writers on the epistemology of disagreement. It then examines arguments bearing on that principle, and on the wider issue. It ends by describing some outstanding questions (...) that thinking about this issue raises. (shrink)

Glymour's "bootstrap" account of confirmation is designed to provide an analysis of evidential relevance, which has been a serious problem for hypothetico-deductivism. As set out in Theory and Evidence, however, the "bootstrap" condition allows confirmation in clear cases of evidential irrelevance. The difficulties with Glymour's account seem to be due to a basic feature which it shares with hypothetico-deductive accounts, and which may explain why neither can give a satisfactory analysis of evidential relevance.

This paper assesses several prominent recent attacks on the view that epistemic justification is conceptually prior to knowledge. I argue that this view—call it the Received View (RV)—emerges from these attacks unscathed. I start with Timothy Williamson’s two strongest arguments for the claim that all evidence is knowledge (E>K), which impugns RV when combined with the claim that justification depends on evidence. One of Williamson’s arguments assumes a false epistemic closure principle; the other misses some alternative (to E>K) explanations of (...) a putative fact about the evidence a particular subject has. Next, I neutralize each of Jonathan Sutton’s three recent arguments to the conclusion that any justified belief constitutes knowledge. Finally, I consider a recent analysis of justification due to Alexander Bird, according to which justified belief is possible knowledge. I argue that Bird’s analysis delivers neither a sufficient nor (more importantly) a necessary condition for justification. [Word count: 149]. (shrink)

In some of the most important recent work in religious epistemology, Paul Moser (2002, 2004, 2008) develops a multifaceted reply to a prominent attack on belief in God—what we’ll call the Hiddenness Argument. This paper raises a number of worries about Moser’s novel treatment of the Hiddenness Argument. After laying out the version of that argument Moser most explicitly engages, we explain the four main elements of Moser’s reply and argue that it stands or falls with two pieces in particular—what (...) we call the Purposively Available Evidence Argument and the Cognitive Idolatry Argument. We then show that the Cognitive Idolatry Argument fails, leaving the Purposively Available Evidence Argument as Moser’s only potentially viable objection to the Hiddenness Argument. We conclude that Moser’s treatment of the Hiddenness Argument depends crucially on some controversial epistemological claims about certain of our moral beliefs, and is thus considerably more vulnerable than many have recognized. (shrink)

We argue that if evidence were knowledge, then there wouldn’t be any Gettier cases, and justification would fail to be closed in egregious ways. But there are Gettier cases, and justification does not fail to be close in egregious ways. Therefore, evidence isn’t knowledge.

Many legal disputes turn on scientific, especially statistical, evidence. Traditionally scientists have accepted only that statistical evidence which satisfies a 95 percent (or 99 percent) rule — that is, only evidence which has less than five percent (or one percent) probability of resulting from chance.The rationale for this rule is the reluctance of scientists to accept anything less than the best-supported new knowledge. The rule reflects the internal needs of scientific practice. However, when uncritically adopted as a rule for admitting (...) legal evidence, the seemingly innocuous 95 percent rule distorts the balance of interests historically protected by the legal system. In particular, plaintiffs in toxic tort and employment discrimination suits are effectively held to a heavier burden of proof in showing that their injuries were more probably than not caused by the defendant's actions. The result is that too many victims of toxic torts or employment discrimination cannot win legal redress for their injuries. (shrink)

The coherence of the whole truth is a presupposition of any holistic coherence theory of justification that postulates a positive connection between justification and truth, for unless the whole truth is itself systemically coherent there is no reason to look for systemic coherence when deciding whether one is justified in accepting a given body of beliefs as true. This paper develops a formal model of holistic evidential coherence and uses this model to formalize and defend the claim that the whole (...) truth must be coherent in an evidential sense. (shrink)

Bayesian epistemology postulates a probabilistic analysis of many sorts of ordinary and scientific reasoning. Huber ([2005]) has provided a novel criticism of Bayesianism, whose core argument involves a challenging issue: confirmation by uncertain evidence. In this paper, we argue that under a properly defined Bayesian account of confirmation by uncertain evidence, Huber's criticism fails. By contrast, our discussion will highlight what we take as some new and appealing features of Bayesian confirmation theory. Introduction Uncertain Evidence and Bayesian Confirmation Bayesian Confirmation (...) by Uncertain Evidence: Test Cases and Basic Principles CiteULike Connotea Del.icio.us What's this? (shrink)

fits our evidence.[1] I will propose some potential counter-examples to test this evidentialist thesis. My main intention in presenting the “counter-examples” is to better understand Feldman’s evidentialism, and evidentialism in general. How are we to understand what our evidence is, how it works, and how are we to understand the phrase “epistemically ought to believe” such that evidentialism might make sense as a plausible thesis in light of the examples? Of course, we may decide that there’s no such way to (...) understand evidentialism -- that it just isn’t a plausible thesis. I must admit that my suspicions lean in that direction. But the potential counter-examples are put forward, not in a refutational spirit (though I have nothing against good refutations in philosophy), but as an invitation to evidentialists and potential evidentialists to refine and/or explain their thesis in light of the at least apparent problems that the examples highlight. (shrink)

Timothy Williamson's epistemology leads to a fairly radical version of scepticism. According to him, all knowledge is evidence. It follows that if S knows p, the evidential probability for S that p is 1. I explain Williamson's infallibilist account of perceptual knowledge, contrasting it with Peter Klein's, and argue that Klein's account leads to a certain problem which Williamson's can avoid. Williamson can allow that perceptual knowledge is possible and that all knowledge is evidence, while at the same time avoiding (...) Klein's problem. But while Williamson can allow that we know some things through experience, there are very many things he must say we cannot know. Given just how very many these are, he should be considered a sceptic. (shrink)

Abstract: This paper considers the question of whether it is possible to be mistaken about the content of our first-order intentional states. For proponents of the rational agency model of self-knowledge, such failures might seem very difficult to explain. On this model, the authority of self-knowledge is not based on inference from evidence, but rather originates in our capacity, as rational agents, to shape our beliefs and other intentional states. To believe that one believes that p, on this view, constitutes (...) one's belief that p and so self-knowledge involves a constitutive relation between first- and second-order beliefs. If this is true, it is hard to see how those second-order beliefs could ever be false.I develop two counter-examples which show that despite the constitutive relation between first- and second-order beliefs in standard cases of self-knowledge, it is possible to be mistaken, and even self-deceived, about the content of one's own beliefs. These counter-examples do not show that the rational agency model is mistaken—rather, they show that the possibility of estrangement from one's own mental life means that, even within the rational agency model, it is possible to have false second-order beliefs about the content of one's first-order beliefs. The authority of self-knowledge does not entail that to believe that one believes that p suffices to make it the case that one believes that p. (shrink)

Few concepts have been considered as essential to the theory of knowledge and rational belief as that of evidence. The simplest theory which accounts for this is evidentialism, the view that epistemic justification for belief--the kind of justification typically taken to be required for knowledge--is determined solely by considerations pertaining to one's evidence. In this ground-breaking book, leading epistemologists from across the spectrum challenge and refine evidentialism, sometimes suggesting that it needs to be expanded in quite surprising directions. Following this, (...) the twin pillars of contemporary evidentialism--Earl Conee and Richard Feldman--respond to each essay. This engaging debate covers a vast number of issues, and will illuminate and inform. (shrink)

If knowing requires believing on the basis of evidence that entails what’s believed, we have hardly any knowledge at all. Hence the near-universal acceptance of fallibilism in epistemology: if it's true that "we are all fallibilists now" (Siegel 1997: 164), that's because denying that one can know on the basis of non-entailing evidence1is, it seems, not an option if we're to preserve the very strong appearance that we do know many things (Cohen 1988: 91). Hence the significance of concessive knowledge (...) attributions (CKAs) (Rysiew 2001)—i.e., sentences of the form 'S knows that p, but it's possible that q' (where q entails not-p). To many, utterances of such sentences sound very odd indeed. According to David Lewis (1996: 550), however, such sentences are merely "overt, explicit" statements of fallibilism; if so, their seeming incoherence suggests that, contrary to our everyday epistemic pretensions, "knowledge must be by definition infallible" after all (ibid.: 549). -/- Recently Jason Stanley (2005) has defended fallibilism against the Lewisian worry that overtly fallibilistic speech is incoherent. According yo Stanley, CKAs are not just odd-sounding: in most cases, they are simply false. But this doesn't impugn fallibilism. Insofar as the odd-sounding utterances Lewis cites state the fallibilist idea, the latter portion thereof ('S cannot eliminate a certain possibility in which not-p', e.g.) expresses the idea that the subject's evidence doesn't entail what's (allegedly) known (hence, the negation of any contrary propositions). According to Stanley, however, this is not the best reading of the possibility clauses CKAs contain. On the correct account of the latter, while the sentences Lewis cites are almost always self-contradictory, they don't capture the fallibilist idea after all. Here, we argue that the sentences in question do express precisely the fallibilist idea, but argue that Lewis has nonetheless failed to raise a problem for the latter. In addition, we respond to worries that the resulting view of the semantics of epistemic possibility statements has certain unacceptable consequences. (shrink)

“Evidence” in the form of data collected and analysis thereof is fundamental to medicine, health and science. In this paper, we discuss the “evidence-based” aspect of evidence-based medicine in terms of statistical inference, acknowledging that this latter field of statistical inference often also goes by various near-synonymous names—such as inductive inference (amongst philosophers), econometrics (amongst economists), machine learning (amongst computer scientists) and, in more recent times, data mining (in some circles). Three central issues to this discussion of “evidence-based” are (i) (...) whether or not the statistical analysis can and/or should be objective and/or whether or not (subjective) prior knowledge can and/or should be incorporated, (ii) whether or not the analysis should be invariant to the framing of the problem (e.g. does it matter whether we analyse the ratio of proportions of morbidity to non-morbidity rather than simply the proportion of morbidity?), and (iii) whether or not, as we get more and more data, our analysis should be able to converge arbitrarily closely to the process which is generating our observed data. For many problems of data analysis, it would appear that desiderata (ii) and (iii) above require us to invoke at least some form of subjective (Bayesian) prior knowledge. This sits uncomfortably with the understandable but perhaps impossible desire of many medical publications that at least all the statistical hypothesis testing has to be classical non-Bayesian—i.e. it is not permitted to use any (subjective) prior knowledge. (shrink)

Though one believes that P is true, one can have reasons for thinking it false. Yet, it seems that one cannot know that P is true and (still) have reasons for thinking it false. Why is this so? What feature of knowledge (or of reasons) precludes having reasons or evidence to believe (true) what you know to be false? If the connection between reasons (evidence) and what one believes is expressible as a probability relation, it would seem that the only (...) satisfactory explanation of this fact is that when one knows that P is true, the reasons or evidence one has in support of P are such as to confer upon P the probability of 1. It is shown by an application of Bayes' Theorem that any value smaller than 1 would permit having reasons to believe what one knows to be false. Hence, it would seem that knowledge requires conclusive reasons to believe (if reasons or evidence is required at all). (shrink)

J. David Velleman casts foreknowledge of one's own next move as psychologically active. As agents, we form prior intentions about what we will do next. Such prior intentions are licensed self-fulfilling beliefs or directive cognitions. These cognitions differ from ordinary predictions in their psychological relation to the evidence, in that they precede that crucial part of the evidence which consists in the fact that they have been formed. However, once formed, these cognitions are epistemologically unremarkable: they are directly justified by (...) evidence, which saliently includes the fact of their own existence. I argue that Velleman distorts both the epistemology and the etiology of self-knowing agency. Self-knowing agents typically know what they will do next non-evidentially, and yet their knowledge of their own next move is formed in response to their (perspective-relative) epistemic grounds. Velleman's account of self-knowing agency is doubly distortive because it ignores the role of the purely first-person point of view which typically characterizes such agency. In developing an alternative account of self-knowing agency, I argue that the kind of knowledge that we typically have of what we are about to do is like the kind of knowledge we have when we non-evidentially know what our own current, conscious propositional thoughts are. We can non-evidentially know what we think in virtue of having made up our minds what to think. Likewise, we can non-evidentially know what we are about to do in virtue of having settled on what to do next. (shrink)

In his recent book, Knowledge in a Social World, Alvin Goldman claims to have established that if a reasoner starts with accurate estimates of the reliability of new evidence and conditionalizes on this evidence, then this reasoner is objectively likely to end up closer to the truth. In this paper, I argue that Goldman's result is not nearly as philosophically significant as he would have us believe. First, accurately estimating the reliability of evidence – in the sense that Goldman requires (...) – is not quite as easy as it might sound. Second, being objectively likely to end up closer to the truth – in the sense that Goldman establishes – is not quite as valuable as it might sound. (shrink)

We argue, contrary to epistemological orthodoxy, that knowledge is not purely epistemic -- that knowledge is not simply a matter of truth-related factors (evidence, reliability, etc.). We do this by arguing for a pragmatic condition on knowledge, KA: if a subject knows that p, then she is rational to act as if p. KA, together with fallibilism, entails that knowledge is not purely epistemic. We support KA by appealing tothe role of knowledge-citations in defending and criticizing actions, and by giving (...) a principled argument for KA, based on the inference rule KB: if a subject knows that A is the best thing she can do, she is rational to do A. In the second half of the paper, we consider and reject the two most promising objections to our ease for KA, one based on the Gricean notion of conversational implicature and the other based on a contextualist maneuver. (shrink)

The assumption that we largely lack reasons for accepting testimony has dominated its epistemology. Given the further assumption that whatever reasons we do have are insufficient to justify our testimonial beliefs, many conclude that any account of testimonial knowledge must allow credulity to be justified. In this paper I argue that both of these assumptions are false. Our responses to testimony are guided by our background beliefs as to the testimony as a type, the testimonial situation, the testifier''s character and (...) the truth of the proposition testified to. These beliefs provide reasons for our responses. Thus, we usually do have reasons, in the sense of propositions believed, for accepting testimony and these reasons can provide evidence for the testimonial beliefs we form. (shrink)

We must allow that knowledge can be transmitted. But to allow this is to allow that an individual can know a proposition despite lacking any evidence for it and reaching belief by an unreliable means. So some explanation is required as to how knowledge rather than belief is transmitted. This paper considers two non-individualistic explanations: one in terms of knowledge existing autonomously, the other in terms of it existing as a property of communities. And it attempts to decide what is (...) at issue between these explanations. (shrink)

George Bealer argues that intuitions are not only reliable indicators of truth, they are necessary to the philosophical endeavor. Specifically, he thinks that intuitions are essential sources of evidence for epistemic justification. I argue that Bealer's defense of intuitions either (1) is insufficient to show that actual human beings are in a position to use intuitions for epistemic justification, or (2) begs the question. The growing empirical data about our intuitions support the view that humans are not creatures appropriately positioned (...) to use intuitions for epistemic justification in the way Bealer suggests. Without the appropriate empirical evidence that humans are beings so positioned, his view begs the question against those who think that intuitions are not reliable guides to truth. (shrink)

This paper critically analyzes Sherrilyn Roush’s (Tracking truth: knowledge, evidence and science, 2005) definition of evidence and especially her powerful defence that in the ideal, a claim should be probable to be evidence for anything. We suggest that Roush treats not one sense of ‘evidence’ but three: relevance, leveraging and grounds for knowledge; and that different parts of her argument fare differently with respect to different senses. For relevance, we argue that probable evidence is sufficient but not necessary for Roush’s (...) own two criteria of evidence to be met. With respect to grounds for knowledge, we agree that high probability evidence is indeed ideal for the central reason Roush gives: When believing a hypothesis on the basis of e it is desirable that e be probable. But we maintain that her further argument that Bayesians need probable evidence to warrant the method they recommend for belief revision rests on a mistaken interpretation of Bayesian conditionalization. Moreover, we argue that attempts to reconcile Roush’s arguments with Bayesianism fail. For leveraging, which we agree is a matter of great importance, the requirement that evidence be probable suffices for leveraging to the probability of the hypothesis if either one of Roush’s two criteria for evidence are met. Insisting on both then seems excessive. To finish, we show how evidence, as Roush defines it, can fail to track the hypothesis. This can remedied by adding a requirement that evidence be probable, suggesting another rationale for taking probable evidence as ideal—but only for a grounds-for-knowledge sense of evidence. (shrink)

Bayesian epistemology suggests various ways of measuring the support that a piece of evidence provides a hypothesis. Such measures are defined in terms of a subjective probability assignment, pr, over propositions entertained by an agent. The most standard measure (where “H” stands for “hypothesis” and “E” stands for “evidence”) is.

The question of whether or not to partition data for the purposes of inferring phylogenetic hypotheses remains controversial. Opinions have been especially divided since Kluge's (1989, Systematic Zoology 38, 7–25) claim that data partitioning violates the requirement of total evidence (RTE). Unfortunately, advocacy for or against the RTE has not been based on accurate portrayals of the requirement. The RTE is a basic maxim for non-deductive inference, stipulating that evidence must be considered if it has relevance to an inference. Evidence (...) is relevant if it has a positive or negative effect on a given conclusion. In the case of ℈partitioned’ phylogenetic inferences, the RTE is violated, and the basis for rational belief in any conclusion is compromised, unless it is shown that the partitions are evidentially irrelevant to one another. The goal of phylogenetic systematics is to hypothesize past causal conditions to account for observed shared similarities among two or more species. Such inferences are non-deductive, necessitating consideration of the RTE. Some phylogeneticists claim the parsimony criterion as justification for the RTE. There is no relation between the two – parsimony is a relation between a hypothesis and causal question(s). Parsimony does not dictate the content of premises prior to an inference. ℈Taxonomic congruence,’ ℈supertrees,’ and ℈conditional combination’ methods violate the RTE. Taxonomic congruence and supertree methods also fail to achieve the intended goal of phylogenetic inference, such that ℈consensus trees’ and ℈supertrees’ lack an empirical basis. ℈Conditional combination’ is problematic because hypotheses derived from partitioned data cannot be compared – a causal hypothesis inferred to account for a set of effects only has relevance to those effects, not any comparative relevance to other causal hypotheses. A similar problem arises in the comparisons of hypotheses derived from different causal theories. (shrink)

In What Science Knows, the Australian philosopher and mathematician James Franklin explains in captivating and straightforward prose how science works its magic ...

Oxford Studies in Epistemology is a biennial publicaton which offers a regular snapshot of state-of-the-art work in this important field.

Because “evidence” is at issue in evidence-based medicine (EBM), the critical responses to the movement have taken up themes from post-positivist philosophy of science to demonstrate the untenability of the objectivist account of evidence. While these post-positivist critiques seem largely correct, I propose that when they focus their analyses on what counts as evidence, the critics miss important and desirable pragmatic features of the evidence-based approach. This article redirects critical attention toward EBM’s rigid hierarchy of evidence as the culprit of (...) its objectionable epistemic practices. It reframes the EBM discourse in light of a distinction between objectivist and pragmatic epistemology, which allows for a more nuanced analysis of EBM than previously offered: one that is not either/or in its evaluation of the decision-making technology as either iconoclastic or creedal. -/- . (shrink)

Timothy Williamson’s project in Knowledge and Its Limits (Williamson, 2000)1 includes proposals for substantial revisions in the received approach to epistemology. One received view is that knowledge is conceptualized in terms of a conjunction of factors that are individually necessary and jointly sufficient for knowing. A central aim of epistemology is to state such necessary and sufficient conditions. Against this received view, Williamson argues that a necessary but insufficient condition need not be a conjunct of a non-circular necessary and sufficient (...) condition. Although being coloured is a necessary but insufficient condition for being red, we cannot state a necessary and sufficient condition for being red by conjoining being coloured with other properties specified without reference to red. Neither the equation ‘Red = coloured + X’ nor the equation ‘Knowledge = true belief + X’ need have a non-circular solution. (3) Williamson further argues that we have inductive reasons for thinking that no analysis of the concept knows of the standard kind is correct. The inductive reasons are simply the history of failed attempts at such “factorizing” or “decompositional” analyses. Williamson not only rejects the prospect of explaining knowledge in terms of belief, justification, and evidence, but he proposes to reverse the order of explanation. That order of explanation has been reversed in this book. The concept knows is fundamental, the primary implement of epistemological inquiry. (185) It is not altogether easy, however, to reconcile this radical program with other things Williamson says in the book. In particular, the book contains two rather unrelated accounts of knowing, and one of these accounts appeals to some of the same ingredients that traditional (or semi-traditional) analysts have used in the past. The first account, which appears in Chapter 1, says that knowing is the most general factive stative propositional attitude. The account is presented in terms of three conditions: (1) If Φ is an FMSO [factive mental state operator], from ‘S Φs that A’ one may infer ‘A’.. (shrink)

It is a widely accepted doctrine in epistemology that knowledge has greater value than mere true belief. But although epistemologists regularly pay homage to this doctrine, evidence for it is shaky. Is it based on evidence that ordinary people on the street make evaluative comparisons of knowledge and true belief, and consistently rate the former ahead of the latter? Do they reveal such a preference by some sort of persistent choice behavior? Neither of these scenarios is observed. Rather, epistemologists come (...) to this conclusion because they have some sort of conception or theory of what knowledge is, and they find reasons why people should rate knowledge, so understood, ahead of mere true belief. But what if these epistemological theories are wrong? Then the assumption that knowledge is more valuable than true belief might be in trouble. We don’t wish to take a firm position against the thesis that knowledge is more valuable than true belief. But we begin this paper by arguing that there is one sense of ‘know’ under which the thesis cannot be right. In particular, there seems to be a sense of ‘know’ in which it means, simply, ‘believe truly.’ If this is correct, then knowledge—in this weak sense of the term—cannot be more valuable than true belief. What evidence is there for a weak sense of ‘knowledge’ in which it is equivalent to ‘true belief’? Knowledge seems to contrast with ignorance. Not only do knowledge and ignorance contrast with one another but they seem to exhaust the alternatives, at least for a specified person and fact. Given a true proposition p, Diane either knows p or is ignorant of it. The same point can be expressed using rough synonyms of ‘know.’ Diane is either aware of (the fact that) p or is ignorant of it. She is either cognizant of p or ignorant of it. She either possesses the information that p or she is uninformed (ignorant) of it. To illustrate these suggestions, consider a case discussed by John Hawthorne (2002). If I ask you how many people in the room know that Vienna is the capital of Austria, you will tally up the number of people in the room who possess the information that Vienna is the capital of Austria.. (shrink)

The paper begins by reviewing two problems for fallibilism: the lottery problem, or the problem of explaining why fallible evidence, though otherwise excellent, is not enough to know that one will lose the lottery, and Gettier problems. It is then argued that both problems can be resolved if we note an important illocutionary force of knowledge attributions: namely, that when we attribute knowledge to someone we mean to give the person credit for getting things right. Alternatively, to say that a (...) person knows is to say that she got things right due to her own abilities, efforts and actions, rather than due to dumb luck, or blind chance, or something else. (shrink)

Introduction -- Foundationalism versus coherentism : a dichotomy disclaimed -- Foundationalism undermined -- Coherentism discomposed -- Foundherentism articulated -- The evidence of the senses : refutations and conjectures -- Naturalism disambiguated -- The evidence against reliabilism -- Revolutionary scientism subverted -- Vulgar pragmatism : an unedifying prospect -- Foundherentism ratified -- Selected essays -- "Know" is just a four-letter word -- Knowledge and propaganda : reflections of an old feminist -- "The ethics of belief" reconsidered -- Epistemology legalized : or, (...) truth, justice, and the American way. (shrink)

Part of an early version of this paper was read at the University of Warwick in October 1977, and a later version was read at the Newcastle Royal Institute of Philosophy in November 1977 and at Aberystwyth and Oxford in early 1978. Thanks are due to the many colleagues and friends who made helpful comments on early drafts; special thanks to Hugh Mellor, Rita Nolan and Paul Weiss for detailed written criticisms, and to Don Locke, for very helpful discussions.

Bayesian epistemology addresses epistemological problems with the help of the mathematical theory of probability. It turns out that the probability calculus is especially suited to represent degrees of belief (credences) and to deal with questions of belief change, confirmation, evidence, justification, and coherence. Compared to the informal discussions in traditional epistemology, Bayesian epis- temology allows for a more precise and fine-grained analysis which takes the gradual aspects of these central epistemological notions into account. Bayesian epistemology therefore complements traditional epistemology; it (...) does not re- place it or aim at replacing it. (shrink)

The evidence-based medicine movement advocates basing all medical decisions on certain types of quantitative research data and has stimulated protracted controversy and debate since its inception. Evidence-based medicine presupposes an inaccurate and deficient view of medical knowledge. Michael Polanyi’s theory of tacit knowledge both explains this deficiency and suggests remedies for it. Polanyi shows how all explicit human knowledge depends on a wealth of tacit knowledge which accrues from experience and is essential for problem solving. Edmund Pellegrino’s classic treatment of (...) clinical judgment is examined, and a Polanyian critique of this position demonstrates that tacit knowledge is necessary for understanding how clinical judgment and medical decisions involve persons. An adequate medical epistemology requires much more qualitative research relevant to the clinical encounter and medical decision making than is currently being done. This research is necessary for preventing an uncritical application of evidence-based medicine by health care managers that erodes good clinical practice. Polanyi’s epistemology shows the need for this work and provides the structural core for building an adequate and robust medical epistemology that moves beyond evidence-based medicine. (shrink)

The paper attempts to give an account of the introspective self-knowledge of our own experiences which is in line with representationalism about phenomenal consciousness and the transparency of experience. A two-step model is presented. First, a demonstrative thought of the form ‚I am experiencing this’ is formed which refers to what one experiences, by means of attention. Plausibly, this thought is knowledge, since safe. Second, a non-demonstrative thought of the form ‚I am experiencing a pain’ occurs. This second self-ascription is (...) justified inferentially, on the basis of the first, demonstrative thought. Thus, an account of introspective experiential self-knowledge can be developed which is richer and more adequate to the phenomena than pure reliabilism and Dretske’s displaced perception model. There is really such a thing as introspection, but no inner sense. (shrink)

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

In order for us to have epistemic justification, Sinnott-Armstrong believes we do not have to be able to rule out all sceptical hypotheses. He suggests that it is sufficient if we have 'modestly justified beliefs', i.e., if our evidence rules out all non-sceptical alternatives. I argue that modest justification is not sufficient for epistemic justification. Either modest justification is independent of our ability to rule out sceptical hypotheses, but is not a kind of epistemic justification, or else modest justification is (...) a kind of epistemic justification, but is not truly independent of our ability to rule out sceptical hypotheses. (shrink)

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)

theory of knowledge defended in Timothy Williamson's book Knowledge and its Limits is compared here with the theory defended in the author's articles ‘How Knowledge Works’ and ‘Knowledge and Self-Knowledge’. It is argued that there are affinities between these theories, but that the latter has considerably more explanatory power.

Here’s a boring thought experiment that doesn’t demonstrate anything: Burglary Smith burgled the house last night; Detective Stanley is investigating the crime scene. He acquires evidence sufficient for knowledge that the burglar came in through the window, but finds very little evidence about whether it was Smith or someone else who committed the crime.

The concept of evidence is among the central concerns of epistemology broadly construed. As such, it has long engaged the intellectual energies of both philosophers of science and epistemologists of a more traditional variety. Here I briefly survey some of the more important ideas to have emerged from this tradition of reflection. I then look somewhat more closely at an issue that has recently come to the fore, largely as a result of Williamson's Knowledge and Its Limits: that of whether (...) one's evidence supervenes on one's non-factive mental states. (shrink)

The concept of evidence is central to both epistemology and the philosophy of science. Of course, ‘evidence’ is hardly a philosopher's term of art: it is not only, or even primarily, philosophers who routinely speak of evidence, but also lawyers and judges, historians and scientists, investigative journalists and reporters, as well as the members of numerous other professions and ordinary folk in the course of everyday life. The concept of evidence would thus seem to be on firmer pre-theoretical ground than (...) various other concepts which enjoy similarly central standing within philosophy. (Contrast, for example, the epistemologist's quasi-technical term ‘epistemic justification’.). (shrink)

In this age of post-Moorean modesty, many of us are inclined to doubt that philosophy is in possession of arguments that might genuinely serve to undermine what we ordinarily believe. It may perhaps be conceded that the arguments of the skeptic appear to be utterly compelling; but the Mooreans among us will hold that the very plausibility of our ordinary beliefs is reason enough for supposing that there must be something wrong in the skeptic’s arguments, even if we are unable (...) to say what it is. In so far then, as the pretensions of philosophy to provide a world view rest upon its.. (shrink)

I describe a naive realist conception of perceptual knowledge, which faces a challenge from the idea that normal perceivers and brains-in-vats have equally justified perceptual beliefs. I defend the naive realist position from Nicholas Silins's recent version of this challenge. I argue that Silins's main objection fails, and that the naive realist understanding of perceptual knowledge can be reconciled with the idea that brains-in-vats have justified perceptual beliefs.

The aim of this paper is to examine the kind of evidence that might be adduced in support of relativist semantics of a kind that have recently been proposed for predicates of personal taste, for epistemic modals, for knowledge attributions and for other cases. I shall concentrate on the case of taste predicates, but what I have to say is easily transposed to the other cases just mentioned. I shall begin by considering in general the question of what kind of (...) evidence can be offered in favour of some semantic theory or framework of semantic theorizing. In other words, I shall begin with the difficult question of the empirical significance of semantic theorizing. In Sect. 2, I outline a relativist semantic theory, and in Sect. 3, I review four types of evidence that might be offered in favour of a relativistic framework. I show that the evidence is not conclusive because a sophisticated form of contextualism (or indexical relativism) can stand up to the evidence. However, the evidence can be taken to support the view that either relativism or the sophisticated form of contextualism is correct. (shrink)

The evidence of your own eyes has often been regarded as unproblematic. But we know that people make mistaken observations. This can be looked on as unimportant if there issome class of statements that can serve as evidence for others, or if every statement in our corpus of knowledge is allowed to be no more than probable. Neither of these alternatives is plausible when it comes to machine or robotic observation. Then we must take the possibility of error seriously, and (...) we must be prepared to deal with error quantitatively. The problem of using internal evidence to arrive at error distributions is the main focus of the paper. (shrink)

I want to discuss a problem that arises when you try to combine an attractive account of what constitutes evidence with an independently plausible account of the kind of access we have to our evidence. According to E = K, our evidence consists of what we know. According to the principle of armchair access, if a proposition is part of our evidence we ought to be able to know that this proposition is part of our evidence ‘from the armchair’. Combined, (...) these claims entail that we can have armchair knowledge of the external world. Because it seems that the principle of armchair access is supported by a widely shared intuition about epistemic rationality, it seems we ought to embrace an internalist conception of evidence. I shall argue that this response is mistaken. Because externalism about evidence can accommodate the relevant intuitions about epistemic rationality, the principle of armchair access is unmotivated. We also have independent reasons for preferring externalism about evidence to the principle of armchair access. (shrink)

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)

In a recent article Dylan Dodd has argued that anyone who holds that all knowledge is evidence must concede that we know next to nothing about die external world. The argument is intended to show that any infallibilist account of knowledge is committed to scepticism, and that anyone who identifies our evidence with the propositions we know is committed to infallibilism. I shall offer some reasons for thinking Dodd's argument is unsound, and explain where his argument goes wrong.

Externalism in the philosophy of mind is threatened by the view that subjects are authoritative with regard to the contents of their own intentional states. If externalism is to be reconciled with first-person authority, two issues need to be addressed: (a) how the non-evidence-based character of knowledge of one's own intentional states is compatible with ignorance of the empirical factors that individuate the contents of those states, and (b) how, given externalism, the non-evidence-based character of such knowledge could place its (...) subject in an authoritative position. This paper endorses a standard strategy for dealing with (a). The bulk of the paper is devoted to (b). The aim is to develop an account of first-person authority for a certain class of intentional states that is capable of explaining (1) why knowledge of one's own intentional states is peculiarly authoritative, and (2) why such authority is compatible with externalism. (shrink)

Abstract: While thought experiments play an important role in contemporary analytic philosophy, much remains unclear about thought experiments. In particular, it is still unclear whether the judgments elicited by thought experiments can provide evidence for the premises of philosophical arguments. This article argues that, if an influential and promising view about the nature of the judgments elicited by thought experiments is correct, then many thought experiments in philosophy fail to provide any evidence for the premises of philosophical arguments.

We argue against the knowledge rule of assertion, and in favour of integrating the account of assertion more tightly with our best theories of evidence and action. We think that the knowledge rule has an incredible consequence when it comes to practical deliberation, that it can be right for a person to do something that she can’t properly assert she can do. We develop some vignettes that show how this is possible, and how odd this consequence is. We then argue (...) that these vignettes point towards alternate rules that tie assertion to sufficient evidence-responsiveness or to proper action. These rules have many of the virtues that are commonly claimed for the knowledge rule, but lack the knowledge rule’s problematic consequences when it comes to assertions about what to do. (shrink)

How does a particular experience evidence a particular perceptual belief for us? As Alvin Plantinga (Warrant and Proper Function, Oxford University Press, 1993, p. 98) puts it, "[W]hat makes it the case that a particular way of being appeared to--being appeared to greenly, say--is evidence for the proposition that I see something green?" Promising, but unsuccessful, answers cite a reliable connection between our having the experience and the belief's being true, our having good reason to believe in such a connection, (...) the proper functioning of our faculties, and objective epistemic norms. A superior view, developed here, is that our experience of being appeared to greenly evidences for us that something is green because we have learned to identify green objects by experiences of that sort. Our learning to do so amounts to our adopting an epistemic norm directing us to form that belief on the basis of that experience. (shrink)

Conciliatory views of disagreement maintain that discovering a particular type of disagreement requires that one make doxastic conciliation. In this paper I give a more formal characterization of such a view. After explaining and motivating this view as the correct view regarding the epistemic significance of disagreement, I proceed to defend it from several objections concerning higher-order evidence (evidence about the character of one's evidence) made by Thomas Kelly (2005).

It is often said that belief aims at truth. I argue that if belief has an aim then that aim is knowledge rather than merely truth. My main argument appeals to the impossibility of forming a belief on the basis of evidence that only weakly favours a proposition. This phenomenon, I argue, is a problem for the truth-aim hypothesis. By contrast, it can be given a simple and satisfying explanation on the knowledge-aim hypothesis. Furthermore, the knowledge-aim hypothesis suggests a very (...) plausible account of what it takes for evidence to be sufficiently good to make belief possible. I offer several further considerations in favour of the knowledge-aim hypothesis, and deal with objections. Although the main point of the paper is not to defend the view that belief has an aim, but to adjudicate between accounts of what that aim is, my argument nevertheless requires some attention to the motivation for attributing an aim to belief in the first place. In particular, I will explain an important advantage that this view has over the view that belief is not aim-directed, but only subject to a constitutive norm. (shrink)