In order to reply to the contemporary skeptic’s argument for the conclusion that we don’t have any empirical knowledge about the external world, several authors have proposed different fallibilist theories of knowledge that reject the epistemic closure principle. Holliday, 1–62 2015a), however, shows that almost all of them suffer from either the problem of containment or the problem of vacuous knowledge or both. Furthermore, Holliday suggests that the fallibilist should allow a proposition to have multiple sets of relevant alternatives, each (...) of which is sufficient while none is necessary, if all its members are eliminated, for knowing that proposition. Not completely satisfied with Holliday’s multi-path reply to the skeptic, the author suggests a new single-path relevant-possibility theory of knowledge and argues that it can avoid both the problem of containment and the problem of vacuous knowledge of a certain sort while rejecting skepticism about the external world. (shrink)

The principle of epistemic closure is the claim that what is known to follow from knowledge is known to be true. This intuitively plausible idea is endorsed by a vast majority of knowledge theorists. There are significant problems, however, that have to be addressed if epistemic closure – closed knowledge – is endorsed. The present essay locates the problem for closed knowledge in the separation it imposes between knowledge and evidence. Although it might appear that all that stands between knowing (...) the truth of the premises of a valid inference and knowledge of its conclusion is inferring it from the premises, the evidence for each of the premises may jointly count against the conclusion. The intuitive view regarding inferred knowledge says one thing, the evidence says another. One epistemological framework that seems to have the resources to resolve this tension endorses the view that knowledge always requires conclusive evidence. A second framework resolves the tension by limiting the scope of the closure principle. Only inferences drawn directly from propositions contained in the scope of a single knowledge operator are considered closed. The aim of the present essay is to revive the unpopular third option, the idea that knowledge is open. The essay proceeds by arguing that in different ways the two former frameworks only succeed in relocating the problem, not in resolving it. The first framework, the infallibilist view, relocates the problem to a sharp separation between knowledge of the occurrences of events from knowledge of their chance of occurring, a separation leading to several significant additional problems. The fallibilist view, the second framework, in endorsing closure neglects to take into full account the ways in which evidence fails to be transitive. For instance, evidence can count in favor of a conjunction while counting against each of its conjuncts. This fact, which is argued for in the essay on probabilistic as well as non-probabilistic grounds, is used as the foundation of an argument against closed knowledge that can be used as a way to understand several of the most fundamental challenges of epistemology. Not only can an open knowledge view that is based on open evidence resolve all these problems in a simple and natural way, it can also respond to formidable challenges that significantly hinder other open knowledge views. There are good reasons, then, to view both knowledge and evidence as open. (shrink)

Discrimination is a central epistemic capacity but typically, theories of discrimination only use discrimination as a vehicle for analyzing knowledge. This paper aims at developing a self-contained theory of discrimination. Internalist theories of discrimination fail since there is no compelling correlation between discriminatory capacities and experiences. Moreover, statistical reliabilist theories are also flawed. Only a modal theory of discrimination is promising. Versions of sensitivity and adherence that take particular alternatives into account provide necessary and sufficient conditions on discrimination. Safety in (...) contrast is not sufficient for discrimination as there are cases of safety that are clearly instances of discrimination failure. The developed account of discrimination between objects will be extended to discrimination between kinds and between types. (shrink)

The skeptical puzzle consists of three allegedly incompatible claims: S knows that O, S doesn’t know that ~U, and the claim that knowledge is closed under the known entailment. I consider several famous instances of the puzzle and conclude that in all of those cases the presupposition that O entails ~U is false. I also consider two possible ways for trying to make it true and argue that both strategies ultimate fail. I conclude that this result at least completely discredits (...) any solution that denies the principle of epistemic closure. At most, denying that O entails ~U can itself be seen as a novel solution to the puzzle, preferred to any other solution: it accommodates both non-skeptical and skeptical intuitions but does not require us to give up the principle of closure, embrace contextualism or subject-sensitive invariantism, or deny any commonly accepted principle of epistemology or logic. (shrink)

Resumo O Contextualismo Epistêmico é conhecido por alegar oferecer a melhor resposta para alguns dos principais problemas epistemológicos, dentre eles o problema gerado pelos paradoxos céticos e, por conseguinte, por deter o conhecimento sobre muitas coisas que ordinariamente julgávamos já conhecidas. Da mesma forma, seria uma via capaz de manter a validade do princípio de fechamento dedutivo. O presente texto pretende analisar a teoria contextualista, conforme apresentada por Stewart Cohen, mostrando como o contextualismo resolve essas questões. Na primeira parte do (...) texto apresentaremos alguns problemas (e algumas características históricas) que culminaram no surgimento do contextualismo. Na segunda parte explanaremos a teoria contextualista de Cohen. Em seguida levantamos algumas objeções comumente endereçadas ao contextualismo. Por fim, concluímos que, embora não seja completamente refutada, a teoria contextualista deve dirimir dúvidas e explicar algumas dificuldades para manter a sua plausibilidade. Palavras-Chave: Contextualismo; Ceticismo; Conhecimento; Stewart Cohen. -/- Abstract Epistemic Contextualism is known by his allegation to possess the best answer to some of the major epistemological problems, among them, the problem created by the skeptical paradoxes and therefore the claim that we can know many things we ordinarily claim to know, and also maintains the validity of the closure principle. This paper seeks to examine Contextualism, as presented by Stewart Cohen, showing how Contextualism solves these problems. In the first section of the text I will present some problems (and some historic features) that originated Contextualism. In the second section I will present the Cohen`s Contextualism. Then, we consider some objections raised against the contextualista theory. Finally, we conclude that although these objections are not able to completely refute contextualism its proponents have to give better explanations in order to maintain its plausibility. Keywords: Contextualism; Skepticism; Knowledge; Stewart Cohen. (shrink)

The central question of this article is how to combine counterfactual theories of knowledge with the notion of actuality. It is argued that the straightforward combination of these two elements leads to problems, viz. the problem of easy knowledge and the problem of missing knowledge. In other words, there is overgeneration of knowledge and there is undergeneration of knowledge. The combination of these problems cannot be solved by appealing to methods by which beliefs are formed. An alternative solution is put (...) forward. The key is to rethink the closeness relation that is at the heart of counterfactual theories of knowledge. (shrink)

Skeptical puzzles and arguments often employ knowledge-closure principles . Epistemologists widely believe that an adequate reply to the skeptic should explain why her reasoning is appealing albeit misleading; but it’s unclear what would explain the appeal of the skeptic’s closure principle, if not for its truth. In this paper, I aim to challenge the widespread commitment to knowledge-closure. But I proceed by first examining a new puzzle about failing to know—what I call the New Ignorance Puzzle . This puzzle resembles (...) to the Old Ignorance Puzzle , although it does not involve a closure principle. It instead centers on the standard view of ignorance, a highly intuitive principle stating that ignorance is merely a failure to know. In Sects. 2 and 3, I argue that the best way to solve the New Ignorance Puzzle is to reject the standard view of ignorance and to explain away its appeal via conversational implicature. I then use this solution to the New Ignorance Puzzle as a way of explaining why knowledge-closure principles would seem true, and why abominable conjunctions would seem abominable, even if such principles were false . The upshot is a new way of explaining why the skeptic’s reasoning is appealing albeit misleading. (shrink)

According to the principle of epistemic closure, knowledge is closed under known implication. The principle is intuitive but it is problematic in some cases. Suppose you know you have hands and you know that ‘I have hands’ implies ‘I am not a brain-in-a-vat’. Does it follow that you know you are not a brain-in-a-vat? It seems not; it should not be so easy to refute skepticism. In this and similar cases, we are confronted with a puzzle: epistemic closure is an (...) intuitive principle, but at times, it does not seem that we know by implication. In response to this puzzle, the literature has been mostly polarized between those who are willing to do away with epistemic closure and those who think we cannot live without it. But there is a third way. Here I formulate a restricted version of the principle of epistemic closure. In the standard version, the principle can range over any proposition; in the restricted version, it can only range over those propositions that are within the limits of a given epistemic inquiry and that do not constitute the underlying assumptions of the inquiry. If we adopt the restricted version, I argue, we can preserve the advantages associated with closure, while at the same time avoiding the puzzle I’ve described. My discussion also yields an insight into the nature of knowledge. I argue that knowledge is best understood as a topic-restricted notion, and that such a conception is a natural one given our limited cognitive resources. (shrink)

The topic of this article is the closure of a priori knowability under a priori knowable material implication: if a material conditional is a priori knowable and if the antecedent is a priori knowable, then the consequent is a priori knowable as well. This principle is arguably correct under certain conditions, but there is at least one counterexample when completely unrestricted. To deal with this, Anderson proposes to restrict the closure principle to necessary truths and Horsten suggests to restrict it (...) to formulas that belong to less expressive languages. In this article it is argued that Horsten’s restriction strategy fails, because one can deduce that knowable ignorance entails necessary ignorance from the closure principle and some modest background assumptions, even if the expressive resources do not go beyond those needed to formulate the closure principle itself. It is also argued that it is hard to find a justification for Anderson’s restricted closure principle, because one cannot deduce it even if one assumes very strong modal and epistemic background principles. In addition, there is an independently plausible alternative closure principle that avoids all the problems without the need for restriction. (shrink)

In this paper I look at Fred Dretske’s account of information and knowledge as developed in Knowledge and The Flow of Information. In particular, I translate Dretske’s probabilistic definition of information to a modal logical framework and subsequently use this to explicate the conception of information and its flow which is central to his account, including the notions of channel conditions and relevant alternatives. Some key products of this task are an analysis of the issue of information closure and an (...) investigation into some of the logical properties of Dretske’s account of information flow. (shrink)

Tracking theories of knowledge are widely known to have the consequence that knowledge is not closed. Recent arguments by Vogel and Hawthorne claim both that there are no legitimate examples of knowledge without closure and that the costs of theories that deny closure are too great. This paper considers the tracking theories of Dretske and Nozick and the arguments by Vogel and Hawthorne. We reject the arguments of Vogel and Hawthorne and evaluate the costs of closure denial for tracking theories (...) of knowledge. (shrink)

A certain interpretation of Wittgenstein’s remarks in On Certaintyadvanced by such figures as Hilary Putnam, Peter Strawson, Avrum Stroll and Crispin Wrighthas become common currency in the recent literature. In particular, this reading focuses upon the supposed anti-sceptical import of the Wittgensteinian notion of a “hinge” proposition. In this paper it is argued that this interpretation is flawed both on the grounds that there is insufficient textual support for this reading and that, in any case, it leads to unpalatable philosophical (...) problems. Moreover, it is claimed that the popularity of this construal of On Certainty in the contemporary debate reflects an implicit commitment to the contentious doctrine of epistemological internalism. Nevertheless, it is argued that, suitably modified along the epistemologically externalist lines suggested by Michael Williams, one might be able to resurrect a viable anti-sceptical hinge proposition thesis. Furthermore, it is claimed that such a conception of the notion also receives some, albeit inconclusive, textual support from On Certainty. (shrink)

Something about this argument sounds funny. As we’ll see, though, it takes some care to identify exactly what Moore has done wrong. Iwill assume that Moore knows premise (2) to be true. One could inquire into how he knows it, and whether that knowledge can be defeated; but Iwon’t. I’ll focus instead on what epistemic relations Moore has to premise (1) and to his conclusion (3). It may matter which epistemic relations we choose to consider. Some philosophers will diagnose Moore’s (...) argument using Contextualist machinery. They’ll say. (shrink)

But it’s not the mere fact that the RA theorist needs an account of ‘ruling out’ and ‘relevance’ that has tended to lead people to regard the RA approach with suspicion. In itself, this simply means that the RA theorist has some further work to do; and what theorist doesn’t? No; the principal source of scepticism regarding the ability of the RA theorist to come up with a complete and satisfactory account of knowing stems, rather, from an unhappiness with the (...) specific elaborations of the core RA claim that various theorists have offered; for these elaborations have typically involved some rather controversial claims and/or assumptions, and it is against these claims/assumptions that the bulk of the criticism of the whole RA approach has been directed. (shrink)

To resolve the lottery paradox, the “no-justification account” proposes that one is not justified in believing that one's lottery ticket is a loser. The no-justification account commits to what I call “the Harman-style skepticism”. In reply, proponents of the no-justification account typically downplay the Harman-style skepticism. In this paper, I argue that the no-justification reply to the Harman-style skepticism is untenable. Moreover, I argue that the no-justification account is epistemically ad hoc. My arguments are based on a rather surprising finding (...) that the no-justification account implies that people living in Taiwan typically suffer from the Harman-style skepticism. (shrink)

O presente volume se trata de uma coletânea de artigos que reúne alguns dos trabalhos propostos para o evento “III International Colloquium of Analytic Epistemology and VII Conference of Social Epistemology”, realizado entre os dias 27 e 30 de Novembro de 2018, na Universidade Federal de Santa Maria. O “III International Colloquium of Analytic Epistemology and VII Conference of Social Epistemology” é um dos principais eventos de Epistemologia analítica da América Latina e reúne especialistas do Brasil e do exterior para (...) promover debates de alto nível sobre temas que fazem parte da agenda contemporânea no que se refere ao debate analítico contemporâneo acerca da Epistemologia. (shrink)

This should be fairly close to the text of this paper as it appears in The Southern Journal of Philosophy 38 (2000), Spindel Conference Supplement: 121-148.

In this paper I draw attention to a peculiar epistemic feature exhibited by certain deductively valid inferences. Certain deductively valid inferences are unable to enhance the reliability of one's belief that the conclusion is true—in a sense that will be fully explained. As I shall show, this feature is demonstrably present in certain philosophically significant inferences—such as GE Moore's notorious 'proof' of the existence of the external world. I suggest that this peculiar epistemic feature might be correlated with the much (...) discussed phenomenon that Crispin Wright and Martin Davies have called 'transmission failure'—the apparent failure, on the part of some deductively valid inferences to transmit one's justification for believing the premises. (shrink)

Is the relation between properties and the causal powers they confer necessary, or contingent? Necessary, says Sydney Shoemaker, on pain of skepticism about the properties. Contingent, says David Lewis, swallowing the skeptical conclusion. I shall argue that Lewis is right about the metaphysics, but that Shoemaker and Lewis are wrong about the epistemology. Properties have intrinsic natures (quiddities), which we can know.

It is widely thought that if knowledge requires sensitivity, knowledge is not closed because sensitivity is not closed. This paper argues that there is no valid argument from sensitivity failure to non-closure of knowledge. Sensitivity does not imply non-closure of knowledge. Closure considerations cannot be used to adjudicate between safety and sensitivity accounts of knowledge.

Perhaps the most dominant anti‐sceptical proposal in recent literature –advanced by such figures as Stewart Cohen, Keith DeRose and David Lewis –is the contextualist response to radical scepticism. Central to the contextualist thesis is the claim that, unlike other non‐contextualist anti‐sceptical theories, contextualism offers a dissolution of the sceptical paradox that respects our common sense epistemological intuitions. Taking DeRose's view as representative of the contextualist position, it is argued that instead of offering us an intuitive response to scepticism, contextualism is (...) actually committed to a revisionist stance as regards our everyday usage of epistemic terms. In particular, it is argued that the thesis fails to present a satisfactory explication of a notion –that of‘epistemic descent’– that is pivotal to the anti‐sceptical import of the account. On the positive side, however, it is claimed that although the contextualist response to scepticism is ultimately unsatisfying, DeRose's theory does contain within it the framework for a completely different ‐ and far more persuasive ‐ account of the‘phenomenology’of scepticism which runs along non‐contextualist lines. (shrink)

In this paper we survey some main arguments for and against epistemological contextualism. We distinguish and discuss various kinds of contextualism, such as attributer contextualism (the most influential version of which is semantic, conversational, or radical contextualism); indexicalism; proto-contextualism; Wittgensteinian contextualism; subject, inferential, or issue contextualism; epistemic contextualism; and virtue contextualism. Starting with a sketch of Dretske's Relevant Alternatives Theory and Nozick's Tracking Account of Knowledge, we reconstruct the history of various forms of contextualism and the ways contextualists try to (...) handle some notorious epistemological quandaries, especially skepticism and the lottery paradox. Then we outline the most important problems that contextualist theories face, and give overviews of their criticisms and defenses as developed in this issue. (shrink)

So, C. I don’t know that T. Premises 1 and 2 are both plausible. However, C seems false—I do seem to know that there is a tree before me. AI presents a puzzle because its two plausible premises yield a conclusion whose negation is plausible. And no matter whether we accept or reject AI, we find that we must give up something plausible—either premise 1, premise 2, or the negation of C. But which of these should we give up? I (...) call this question the skeptical puzzle.1 Recently, Mark Heller2 has argued that we can solve the skeptical puzzle by giving up premise 2. I argue, however, that Heller does not adequately respond to an objection to his proposed solution. I go on to argue that we can solve the skeptical puzzle by giving up premise 1. (shrink)

Author's note: This is a piece from the very early stage of my career. Please regard it as a historical document.

The gist of modal epistemology is expressed in the idea that you fail to know if you do believe truly but it is seriously possible for you to believe falsely. According to subjunctivism, this idea is captured by certain subjunctive conditionals. One formulation invokes a safety condition—“If S had believed P, then P would have been the case,” while the other invokes a sensitivity condition—“If P had been false, S would not have believed that P.” According to simple subjunctivism, such (...) conditionals do not contrapose and Sosa derives important epistemological consequences which favor safety from this difference. However, simple subjunctivism is inadequate. I return to Goodman and his analysis of factuals and propose modal stability, which is restricted sensitivity or enhanced safety as a proper epistemic condition for the non-accidental connection between the basis for the belief and the relevant facts of the matter. The idea of modal stability combines robustness (benefi ts of safety) with responsiveness to facts (benefi ts of sensitivity) and recovers the original motivation for the relevant alternatives theory—when testing for claims of knowledge that p we ask what might be the case if not-p, but we ignore irrelevant possibilities. Epistemic modal conditions should be expressed in terms of conditionals of connection which contrapose within the limits of relevance. (shrink)

How should the contrastivist formulate closure? That is, given that knowledge is a ternary contrastive state Kspq (s knows that p rather than q), how does this state extend under entailment? In what follows, I will identify adequacy conditions for closure, criticize the extant invariantist and contextualist closure schemas, and provide a contrastive schema based on the idea of extending answers. I will conclude that only the contrastivist can adequately formulate closure.

The epistemic closure principle says that knowledge is closed under known entailment. The closure principle is deeply implicated in numerous core debates in contemporary epistemology. Closure’s opponents claim that there are good theoretical reasons to abandon it. Closure’s proponents claim that it is a defining feature of ordinary thought and talk and, thus, abandoning it is radically revisionary. But evidence for these claims about ordinary practice has thus far been anecdotal. In this paper, I report five studies on the status (...) of epistemic closure in ordinary practice. Despite decades of widespread assumptions to the contrary in philosophy, ordinary practice is ambivalent about closure. Ordinary practice does not endorse an unqualified version of the epistemic closure principle, although it might endorse a source-relative version of the principle. In particular, whereas inferential knowledge is not viewed as closed under known entailment, perceptual knowledge might be. (shrink)

This dissertation examines some of ways of evaluating beliefs, relevant to epistemology and to metaphysics. Some problems in normative epistemology are solved by properly relating justified belief, rational belief, and knowledge. Chapter 1 uses this strategy to defend externalism about justified belief. Chapters 3 and 4 defend the view that knowledge is the epistemic standard we aim for our beliefs to meet. Chapter 2 investigates which beliefs are improper because formed in an objectionably circular way. The findings support the Moorean (...) response to Brain-In-a-Vat skepticism, by rebutting the objection from ‘easy knowledge’. The theory of justified belief developed in chapter 1 underwrites the Moorean reply. Chapters 5 and 6 make a non-epistemic way of evaluating beliefs central to metaphysics. To understand relativity or vagueness in a subject-matter, we must hold that being true or false is not the metaphysically serious evaluation of how a belief answers to reality. Either verdict on a borderline case is ‘acceptable’ in the metaphysically serious sense. For a matter to be relative is for the ‘acceptability’ of affirming the proposition to vary between judges. Chapters 5 and 6 sketch an approach to metaphysics built from the notion of ‘metaphysically acceptable judgment’, with chapter 6 concentrating on vagueness, and chapter 5 focusing on relativism about knowledge. Chapter 5 argues that the lottery and preface puzzles manifest central features of our concept of knowledge. The proposed version of relativism about knowledge is the only theory to respect those features. The view of knowledge presented in chapter 5 is not an isolated metaphysical extravagance, as the same framework is needed for the right metaphysics of everything that’s vague. It is worth noting that my solution to the lottery puzzle is metaphysical relativism about knowledge, but my rebuttal of Brain-In-a-Vat skepticism concerns epistemic circularity and belongs to normative epistemology. Much recent work incorrectly assumes that the two puzzles receive the same treatment. (shrink)

Epistemic closure has been a central issue in epistemology over the last forty years. According to versions of the relevant alternatives and subjunctivist theories of knowledge, epistemic closure can fail: an agent who knows some propositions can fail to know a logical consequence of those propositions, even if the agent explicitly believes the consequence (having “competently deduced” it from the known propositions). In this sense, the claim that epistemic closure can fail must be distinguished from the fact that agents do (...) not always believe, let alone know, the consequences of what they know—a fact that raises the “problem of logical omniscience” that has been central in epistemic logic. This paper, part I of II, is a study of epistemic closure from the perspective of epistemic logic. First, I introduce models for epistemic logic, based on Lewis’s models for counterfactuals, that correspond closely to the pictures of the relevant alternatives and subjunctivist theories of knowledge in epistemology. Second, I give an exact characterization of the closure properties of knowledge according to these theories, as formalized. Finally, I consider the relation between closure and higher-order knowledge. The philosophical repercussions of these results and results from part II, which prompt a reassessment of the issue of closure in epistemology, are discussed further in companion papers. As a contribution to modal logic, this paper demonstrates an alternative approach to proving modal completeness theorems, without the standard canonical model construction. By “modal decomposition” I obtain completeness and other results for two non-normal modal logics with respect to new semantics. One of these logics, dubbed the logic of ranked relevant alternatives, appears not to have been previously identified in the modal logic literature. More broadly, the paper presents epistemology as a rich area for logical study. (shrink)

I seem to know that I won't experience spaceflight but also that if I win the lottery, then I will take a flight into space. Suppose I competently deduce from these propositions that I won't win the lottery. Competent deduction from known premises seems to yield knowledge of the deduced conclusion. So it seems that I know that I won't win the lottery; but it also seems clear that I don't know this, despite the minuscule probability of my winning (if (...) I have a lottery ticket). So we have a puzzle. It seems to generalize, for analogues of the lottery-proposition threaten almost all ordinary knowledge attributions. For example, my apparent knowledge that my bike is parked outside seems threatened by the possibility that it's been stolen since I parked it, a proposition with a low but non-zero probability; and it seems that I don't know this proposition to be false. Familiar solutions to this family of puzzles incur unacceptable costs—either by rejecting deductive closure for knowledge, or by yielding untenable consequences for ordinary attributions of knowledge or of ignorance. After canvassing and criticizing these solutions, I offer a new solution free of these costs. Knowledge that p requires an explanatory link between the fact that p and the belief that p. This necessary but insufficient condition on knowledge distinguishes actual lottery cases from typical, apparently analogous ‘quasi-lottery’ cases. It does yield scepticism about my not winning the lottery and not experiencing spaceflight, but the scepticism doesn't generalize to quasi-lottery cases such as that involving my bike. (shrink)

The general principle of epistemic closure stipulates that epistemic properties are transmissible through logical means. According to this principle, an epistemic operator, say ε, should satisfy any valid scheme of inference, such as: if ε(p entails q), then ε(p) entails ε(q). The principle of epistemic closure under known entailment (ECKE), a particular instance of epistemic closure, has received a good deal of attention since the last thirty years or so. ECKE states that: if one knows that p entails q, and (...) she knows that p, then she knows that q. It is widely accepted that ECKE constitutes an important piece of the skeptical argument, but the acceptance of an unrestricted version of ECKE is still a matter of debate. On the side of the defenders of ECKE, one finds Stine (1976), Brueckner (1985), Vogel (1990), and Feldman (1995). Others proposed a refutation or a limitation of the principle, like Dretske (1970), Nozick (1981), Hales (1995), Williams (1996), and Sosa (1999). As it turns out, the relevant alternatives view (RAV) elaborated by Dretske, which restricts the scope of ECKE, has been discussed extensively and acknowledged as one of the most important contributions. There is nonetheless a major unsolved difficulty pertaining to Dretske-RAV: the notion of relevant alternatives is defined in such a way that it is bounded by counterfactual possibilities. This ontological import leaves open the door to the skeptic. Some have tried to give more precision to this notion, like Stine (1976), who appealed to a Gricean approach to define relevant alternatives in conversational contexts. My proposal is in accordance with the gist of Dretske’s strategy, i.e. to restrict the validity of ECKE, and I claim that in order to escape the difficulties inherent to RAV one has to introduce a more robust notion, the notion of epistemic context. Epistemic contexts are a subclass of propositional contexts. In that perspective, the closure property is expressed in terms of a property of a relation between epistemic contexts. ECKE holds when and only when either the epistemic context of the premisses is the same as the epistemic context of the conclusion, or the epistemic context change between the premisses and the conclusion is permissible. Permissibility of epistemic context change is a function of consistency. By means of this epistemic context approach, I will show that: (1) epistemic contexts are defined by basic propositions (unchallenged justified beliefs), (2) ECKE holds only under very specific constraints, and (3) the skeptical argument involves a non-permissible change of epistemic context and, by the same token, cannot rely upon ECKE. (shrink)

G. E. Moore famously offered a strikingly straightforward response to the radical sceptic which simply consisted of the claim that one could know, on the basis of one's knowledge that one has hands, that there exists an external world. In general, the Moorean response to scepticism maintains that we can know the denials of sceptical hypotheses on the basis of our knowledge of everyday propositions. In the recent literature two proposals have been put forward to try to accommodate, to varying (...) extents, this Moorean thesis. On the one hand, there are those who endorse an externalist version of contextualism, such as Keith DeRose, who have claimed that there must be some contexts in which Moore is right. More radically still, Ernest Sosa has expanded on this externalist thesis by arguing that, contra DeRose's contextualism, Moore may be right in all contexts. In this paper I evaluate these claims and argue that, suitably modified, one can resurrect the main elements of the Moorean anti-sceptical thesis. (shrink)

According to Fred Dretske's externalist theory of knowledge a subject knows that p if and only if she believes that p and this belief is caused or causally sustained by the information that p. Another famous feature of Dretske's epistemology is his denial that knowledge is closed under known entailment. I argue that, given Dretske's construal of information, he is in fact committed to the view that both information and knowledge are closed under known entailment. Hence, if it is true (...) that, as Dretske also believes, accepting closure leads to skepticism, he must either embrace skepticism or abandon his information theory of knowledge. (shrink)

According to the Relevant Alternatives (RA) Theory of knowledge, knowing that something is the case involves ruling out (only) the relevant alternatives. The conception of knowledge in epistemic logic also involves the elimination of possibilities, but without an explicit distinction, among the possibilities consistent with an agent’s information, between those relevant possibilities that an agent must rule out in order to know and those remote, far-fetched or otherwise irrelevant possibilities. In this article, I propose formalizations of two versions of the (...) RA theory. Doing so clarifies a famous debate in epistemology, pitting Fred Dretske against David Lewis, about whether the RA theorist should accept the principle that knowledge is closed under known implication, familiar as the K axiom in epistemic logic. Dretske’s case against closure under known implication leads to a study of other closure principles, while Lewis’s defense of closure by appeal to the claimed context sensitivity of knowledge attributions leads to a study of the dynamics of context. Having followed the first lead at length in other work, here I focus more on the second, especially on logical issues associated with developing a dynamic epistemic logic of context change over models for the RA theory. (shrink)

Take the following principle (or schema) as the focus of the ensuing discussion (“P” and “Q” are placeholders for propositions): 1 (Closure) If one knows P and competently deduces Q from P, thereby coming to believe Q, while retaining one's knowledge that P, one comes to know that Q. My strategy in outline: first, I want to set out Fred Dretske's classic challenge to (Closure) – a challenge which began in 1970–1971. Then I want to consider a specific, recent counter‐challenge (...) to Dretske's challenge to (Closure) mounted by John Hawthorne, and to defend Dretske's challenge from Hawthorne's counter‐challenge. Doing this is not to invalidate (Closure). In this regard my conclusions are modest: Dretske's challenge to (Closure) is – or, better: can be made – sophisticated and, so far, unmet. (shrink)

A dispute in epistemology has arisen over whether some class of things epistemic (things known or justified, for example) is closed under some operation involving the notion of what follows deductively from members of this class. Very few philosophers these days believe that if you know that p, and p entails q, then you know that q. But many philosophers think that something weaker holds, for instance that if you know that p, and p entails q, then you are in (...) a position to know that p, or if you know that p and you competently deduce p from q, then you know that q. However there are some considerations tracing back to Wittgenstein’s On Certainty and some early work by Fred Dretske that suggests even these weaker principles are false. (shrink)

According to the relevant alternatives theory of knowledge (RA), I know that p only if my evidence eliminates all relevant alternatives to p . Jonathan Schaffer has recently argued that David Lewis's version of RA, which is perhaps the most detailed version yet provided, cannot account for our failure to know in cases involving missed clues, that is, cases in which we see but fail to appreciate decisive evidence. I argue, however, that Lewis's version of RA survives exposure to missed (...) clue cases. Moreover, even though Schaffer maintains that Lewis's Rule of Belief provides no protection against missed clue cases, I argue that we should credit the Rule of Belief with ensuring the survival of Lewis's version of RA. (shrink)

A great deal of discussion in the recent literature has been devoted to the so-called 'McKinsey' paradox which purports to show that semantic externalism is incompatible with the sort of authoritative knowledge that we take ourselves to have of our own thought contents. In this paper I examine one influential epistemological response to this paradox which is due to Crispin Wright and Martin Davies. I argue that it fails to meet the challenge posed by McKinsey but that, if it is (...) set within an externalist epistemology, it may have application to a related paradox that concerns the problem of radical scepticism. (shrink)

According to a Moorean response to skepticism, the standards for knowledge are invariantly comparatively low, and we can know across contexts all that we ordinarily take ourselves to know. It is incumbent upon the Moorean to defend his position by explaining how, in contexts in which S seems to lack knowledge, S can nevertheless have knowledge. The explanation proposed here relies on a warranted-assertability maneuver: Because we are warranted in asserting that S doesn’t know that p, it can seem that (...) S does in fact lack that piece of knowledge. Moreover, this warranted-assertability maneuver is unique and better than similar maneuvers because it makes use of H. P. Grice’s general conversational rule of Quantity—“Do not make your contribution more informative than is required”—in explaining why we are warranted in asserting that S doesn’t know that p. (shrink)

Predicate approaches to modality have been a topic of increased interest in recent intensional logic. Halbach and Welch :71–100, 2009) have proposed a new formal technique to reduce the necessity predicate to an operator, demonstrating that predicate and operator methods are ultimately compatible. This article concerns the question of whether Halbach and Welch’s approach can provide a uniform formal treatment for intensionality. I show that the monotonicity constraint in Halbach and Welch’s proof for necessity fails for almost all possible-worlds theories (...) of knowledge. The nonmonotonicity results demonstrate that the most obvious way of emulating Halbach and Welch’s rapprochement of the predicate and operator fails in the epistemic setting. (shrink)

In this article, I reply to comments on my book by Georgi Gardiner and Joshua DiPaolo. I will first reply to Gardiner's comments, focusing primarily on her doubts about the adjudicative power of function-first epistemology. I will then reply to DiPaolo, who argues that I have misidentified that primary function of the concept of knowledge.

There are a number of relevant alternatives accounts of knowledge in the literature, including those by contextualists (like Lewis and Cohen), and invariantists (like Dretske). Despite widespread discussion of such views, an explication of the notion of relevance is conspicuously absent from the literature. Without a careful explication of that notion, relevant alternatives accounts resist evaluation. This paper attempts to aid in the evaluation of those accounts, by providing an account of relevance. The account rejects two common presuppositions about the (...) notion of relevance. The account holds that worlds, rather than alternatives, are relevant, and that distant worlds can be relevant. Relevant worlds turn out to be those worlds at which an alternative to one’s belief obtains, and is such that one’s epistemic position (with respect to what one believes at the actual world) is worse than it is at the actual world. (shrink)