Epistemologists understand radical skepticism as arising from two principles: Closure and Underdetermination. Both possess intuitive prima facie support for their endorsement. Understanding how they engender skepticism is crucial for any reasonable anti-skeptical attempt. The contemporary discussion has focused on elucidating the relationship between them to ascertain whether they establish distinct skeptical questions and which of the two constitutes the ultimately fundamental threat. Major contributions to this debate are due to Brueckner, Cohen, and Pritchard. This contribution aims at defending Brueckner’s contention (...) that underdetermination expresses the fundamental skeptical threat and that the closure-based argument can ultimately be reduced to it, at least concerning skeptical contexts. This will be achieved by undermining Cohen’s objections to Brueckner on both counts. Cohen’s argument endorses a picture of evidential underdetermination, which, while apt for non-skeptical contexts, cannot be applied to radical skepticism. A comparison with a case of scientific underdetermination is developed to argue for this idea. Our argument is then applied to the principle equivalence issue and to objections against it. It is then shown how this analysis possesses a distinctive effect on our understanding of the skeptical threat and the assessment of successful anti-skeptical strategies. (shrink)

In this paper I defend the claim that justification is closed under conjunction, and confront its most alarming consequence — that one can have justification for believing propositions that are unlikely to be true, given one's evidence.

A Série Investigação Filosófica é uma série de livros de traduções de verbetes da Enciclopédia de Filosofia da Stanford (Stanford Encyclopedia of Philosophy) e de outras plataformas internacionalmente reconhecidas, que intenciona servir tanto como material didático para os professores das diferentes sub-áreas e níveis da Filosofia quanto como material de estudo para a pesquisa e para concursos da área. Nós, professores, sabemos o quão difícil é encontrar bom material em português para indicarmos. E há uma certa deficiência na graduação brasileira (...) de filosofia, principalmente em localizações menos favorecidas, com relação ao conhecimento de outras línguas, como o inglês e o francês. Tentamos, então, suprir essa deficiência, ao introduzirmos essas traduções ao público de língua portuguesa, sem nenhuma finalidade comercial e meramente pela glória da filosofia. (shrink)

The adjective ‘is justified’ has all the hallmarks of a gradable adjective. But the relationship between gradable uses and straightforward predications of the form ‘x is justified’ has been underexplored by epistemologists. In this paper we undertake to do some ground clearing as a prelude to better understanding this relationship.

_ Source: _Page Count 14 One common problem with anti-skepticism and skepticism alike is their failure to account for our sometimes conflicting epistemic intuitions. In order to address this problem and provide a new direction for solving the skeptical puzzle, I consider a modified version of the puzzle that is based on knowledge claims about appearances and does not result in a paradox. I conclude that combining the elements of both the original and modified puzzle can potentially guide us towards (...) solutions that can fully explain the conflict of epistemic intuitions. (shrink)

_ Source: _Page Count 14 One common problem with anti-skepticism and skepticism alike is their failure to account for our sometimes conflicting epistemic intuitions. In order to address this problem and provide a new direction for solving the skeptical puzzle, I consider a modified version of the puzzle that is based on knowledge claims about appearances and does not result in a paradox. I conclude that combining the elements of both the original and modified puzzle can potentially guide us towards (...) solutions that can fully explain the conflict of epistemic intuitions. (shrink)

Evidentialism is the thesis, roughly, that one’s beliefs should fit one’s evidence. The enkratic principle is the thesis, roughly, that one’s beliefs should "line up" with one’s beliefs about which beliefs one ought to have. While both theses have seemed attractive to many, they jointly entail the controversial thesis that self-misleading evidence is impossible. That is to say, if evidentialism and the enkratic principle are both true, one’s evidence cannot support certain false beliefs about which beliefs one’s evidence supports. Recently, (...) a number of epistemologists have challenged the thesis that self-misleading evidence is impossible on the grounds that misleading higher-order evidence does not have the kind of strong and systematic defeating force that would be needed to rule out the possibility of such self-misleading evidence. Here I respond to this challenge by proposing an account of higher-order defeat that does, indeed, render self-misleading evidence impossible. Central to the proposal is the idea that higher-order evidence acquires its normative force by influencing which conditional beliefs it is rational to have. What emerges, I argue, is an independently plausible view of higher-order evidence, which has the additional benefit of allowing us to reconcile evidentialism with the enkratic principle. (shrink)

Dans cet article, je discute l’épistémologie de Pascal Engel, en particulier sa stratégie de réponse aux arguments sceptiques dans Va Savoir!. Après avoir présenté de manière synthétique les grands axes de cette stratégie, je reviens avec plus d’attention sur deux éléments de cette stratégie avec lesquels je suis en désaccord : le rejet par Engel de tout principe de réflexivité épistémique, et le rejet par Engel d’une défense « forte » du sens commun. Je défends qu’un certain principe de réflexivité (...) ne peut pas être raisonnablement rejeté ; puis je montre que l’épistémologie d’Engel ne permet pas d’apporter une réponse satisfaisante au défi sceptique que pose le principe de Méta-Cohérence. Enfin, je soutiens que la seule manière de répondre de manière satisfaisante à ce défi est de recourir à une défense « forte » du sens commun, c’est-à-dire à une stratégie dans laquelle les propositions de sens commun sont justifiées parce qu’elles sont de sens commun. (shrink)

Theories of epistemic justification are commonly assessed by exploring their predictions about particular hypothetical cases – predictions as to whether justification is present or absent in this or that case. With a few exceptions, it is much less common for theories of epistemic justification to be assessed by exploring their predictions about logical principles. The exceptions are a handful of ‘closure’ principles, which have received a lot of attention, and which certain theories of justification are well known to invalidate. But (...) these closure principles are only a small sample of the logical principles that we might consider. In this paper, I will outline four further logical principles that plausibly hold for justification and two which plausibly do not. While my primary aim is just to put these principles forward, I will use them to evaluate some different approaches to justification and (tentatively) conclude that a ‘normic’ theory of justification best captures its logic. (shrink)

I set out the standard view about alleged examples of failure of transmission of warrant, respond to two cases for the view, and argue that the view is false. The first argument for the view neglects the distinction between believing a proposition on the basis of a justification and merely having a justification to believe a proposition. The second argument for the view neglects the position that one's justification for believing a conclusion can be one's premise for the conclusion, rather (...) than simply one's justification for the premise. Finally, the view is false since it is inconsistent with the closure of knowledge as closure is properly understood. (shrink)

Skeptical hypotheses such as the brain-in-a-vat hypothesis provide extremely poor explanations for our sensory experiences. Because these scenarios accommodate virtually any possible set of evidence, the probability of any given set of evidence on the skeptical scenario is near zero; hence, on Bayesian grounds, the scenario is not well supported by the evidence. By contrast, serious theories make reasonably specific predictions about the evidence and are then well supported when these predictions are satisfied.

Saul Kripke argued that the requirement that knowledge eliminate all possibilities of error leads to dogmatism . According to this view, the dogmatism puzzle arises because of a requirement on knowledge that is too strong. The paper argues that dogmatism can be avoided even if we hold on to the strong requirement on knowledge. I show how the argument for dogmatism can be blocked and I argue that the only other approach to the puzzle in the literature is mistaken.

Fred Dretske notoriously claimed that knowledge closure sometimes fails. Crispin Wright agrees that warrant does not transmit in the relevant cases, but only because the agent must already be warranted in believing the conclusion in order to acquire her warrant for the premise. So the agent ends up being warranted in believing, and so knowing, the conclusion in those cases too: closure is preserved. Wright's argument requires that the conclusion's having to be warranted beforehand explains transmission failure. I argue that (...) it doesn't, and that the correct explanation does not imply that the agent will end up warranted in believing the conclusion when transmission fails. Those who agree that transmission does fail in those cases, therefore, might as well follow Dretske in denying knowledge closure too. (shrink)

In this paper, I consider some issues involving a certain closure principle for Structural Justification, a relation between a cognitive subject and a proposition that’s expressed by locutions like ‘S has a source of justification for p’ and ‘p is justifiable for S’. I begin by summarizing recent work by Peter Klein that advances the thesis that the indicated closure principle is plausible but lacks Skeptical utility. I then assess objections to Klein’s thesis based on work by Robert Audi and (...) Anthony Brueckner. One finding is that the typical statement of the relevant closure principle can express a number of different closure principles, and that recognizing this helps to resolve certain disputes. (shrink)

For at least several decades, and arguably since the time of Descartes, it has been fashionable to offer scientific or quasi-scientific arguments for skepticism about human knowledge. I critique five attempts to argue for skeptical conclusions from the findings of science and scientifically informed common sense.

The Consequence Argument has elicited various responses, ranging from acceptance as obviously right to rejection as obviously problematic in one way or another. Here we wish to focus on one specific response, according to which the Consequence Argument begs the question. This is a serious accusation that has not yet been adequately rebutted, and we aim to remedy that in what follows. We begin by giving a formulation of the Consequence Argument. We also offer some tentative proposals about the nature (...) of begging the question. Although the charge of begging the question is frequently made in philosophy, it is surprisingly difficult to pin down the precise nature of this dialectical infelicity (or family of such infelicities). Thus we offer some new proposals about the nature of begging the question with an eye to understanding what is going on in central cases in which the charge is legitimately made. We then defend the Consequence Argument against the charge that it begs the question, so construed. We contend that, whatever the other liabilities of the argument may be, it does not beg the question against the compatibilist. (shrink)

Say that two goals are normatively coincident just in case one cannot aim for one goal without automatically aiming for the other. While knowledge and justification are distinct epistemic goals, with distinct achievement conditions, this paper begins from the suggestion that they are nevertheless normatively coincident—aiming for knowledge and aiming for justification are one and the same activity. A number of surprising consequences follow from this—both specific consequences about how we can ascribe knowledge and justification in lottery cases and more (...) general consequences about the nature of justification and the relationship between justification and evidential probability. Many of these consequences turn out to be at variance with conventional, prevailing views. (shrink)

Consider the skeptic about the external world. Let’s straightaway concede to such a skeptic that perception gives us no conclusive or certain knowledge about our surroundings. Our perceptual justification for beliefs about our surroundings is always defeasible—there are always possible improvements in our epistemic state which would no longer support those beliefs. Let’s also concede to the skeptic that it’s metaphysically possible for us to have all the experiences we’re now having while all those experiences are false. Some philosophers dispute (...) this, but I do not. The skeptic I want to consider goes beyond these familiar points to the much more radical conclusion that our perceptual experiences can’t give us any knowledge or even justification for believing that our surroundings are one way rather than another. (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)

The dominant response to this problem of the criterion focuses on the alleged requirement that we need to know a belief source is reliable in order for us to acquire knowledge by that source. Let us call this requirement, “The KR principle”.

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)

Closure principles say that if you know some proposition which entails a second and you meet further conditions then you know the second. In this paper I construct an argument against closure principles which turns on the idea that knowing a proposition requires that one’s belief-forming process be reliable. My argument parallels an influential argument offered by Timothy Williamson against KK principles–principles that say that if you know some proposition and you meet further conditions then you know that you know (...) the proposition. After offering my argument, I provisionally assess its damage to closure principles and also look at how responses to my argument against closure principles can be used to generate responses to Williamson’s argument against KK principles. (shrink)

Daniel Dombrowski contends that: a number of versions of the ontological argument [OA] are sound; the deity whose existence is most well established by the OA is the deity picked out by Hartshorne’s neoclassical concept of God; skeptics who insist that the OA only shows that “if God exists, then God exists necessarily” are contradicting themselves, and the OA is worth a great deal since it effectively demonstrates the rationality of theism. I argue that theses and are clearly false and (...) offer a presumptive case for thinking that is false, since, absent an independent proof of God’s existence, the theist appears to be in no position to rationally assert. I also show that the Anselmian OA harmonizes rather poorly with a Hartshornean neoclassical conception of God. I conclude by assessing the philosophical and dialectical worth of ontological arguments vis-à-vis establishing the rationality of theism. (shrink)

Skeptics try to persuade us of our ignorance with arguments like the following: 1. I don’t know that I am not a handless brain-in-a-vat [BIV]. 2. If I don’t know that I am not a handless BIV, then I don’t know that I have hands. Therefore, 3. I don’t know that I have hands. The BIV argument is valid, its premises are intuitively compelling, and yet, its conclusion strikes us as absurd. Something has to go, but what? Contextualists contend that (...) an adequate solution to the skeptical problem must: (i) retain epistemic closure, (ii) explain the intuitive force of skeptical arguments by explaining why their premises initially seem so compelling, and (iii) account for the truth of our commonsense judgment that we do possess lots of ordinary knowledge. Contextualists maintain that the key to such a solution is recognizing that the semantic standards for ‘knows’ vary from context to context such that in skeptical contexts the skeptic’s premises are true and so is her conclusion; but in ordinary contexts, her conclusion is false and so is her first premise. Despite its initial attractiveness, the contextualist solution comes at a significant cost, for contextualism has many counterintuitive results. After presenting the contextualist solution, I identify a number of these costs. I then offer a noncontextualist solution that meets the adequacy constraint identified above, while avoiding the costs associated with contextualism. Hence, one of the principal reasons offered for adopting a contextualist theory of knowledge–its supposedly unique ability to adequately resolve the skeptical problem – is undermined. (shrink)

G. E. Moore identified a peculiar form of epistemic irrationality. Wittgenstein called it “Moore’s Paradox”. Neither of them knew exactly what he was talking about. And yet, the vast literature on the problem leaves no room for doubt: the paradox is deep; its resolution, elusive. But, up until now, we haven’t been in a position to appreciate its importance for contemporary epistemology. This paper puts forward an epistemological solution to the paradox. It also seeks to show that the paradox yields (...) counter-examples to deductive closure claims for both epistemic rationality and knowledge that are immune to contextualist pro-closure maneuvers. (shrink)

The Knower Paradox has had a brief but eventful history, and principles of epistemic closure (which say that a subject automatically knows any proposition she knows to be materially implied, or logically entailed, by a proposition she already knows) have been the subject of tremendous debate in epistemic logic and epistemology more generally, especially because the fate of standard arguments for and against skepticism seems to turn on the fate of closure. As far as I can tell, however, no one (...) working in either area has emphasized the result I emphasize in this paper: the Knower Paradox just falsifies even the most widely accepted general principles of epistemic closure. After establishing that result, I discuss five of its more important consequences. (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)

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)

E. J. Coffman defends Peter Klein’s work on epistemic closure against various objections that I raised in an earlier paper. In this paper, I respond to Coffman.

At the very least, externalists about content will accept something like the following claim.

Those of us who have followed Fred Dretske's lead with regard to epistemic closure and its impact on skepticism have been half-wrong for the last four decades. But those who have opposed our Dretskean stance, contextualists in particular, have been just wrong. We have been half-right. Dretske rightly claimed that epistemic status is not closed under logical implication. Unlike the Dretskean cases, the new counterexamples to closure offered here render every form of contextualist pro-closure maneuvering useless. But there is a (...) way of going wrong under Dretske's lead. As the paper argues, Cartesian skepticism thrives on closure failure in a way that is yet to be acknowledged in the literature. The skeptic can make do with principles which are weaker than the familiar closure principles. But I will further claim that this is only a momentary reprieve for the skeptic. As it turns out, one of the weaker principles on which a skeptical modus tollens must rest can be shown false. (shrink)

Dretske's conclusive reasons account of knowledge is designed to explain how epistemic closure can fail when the evidence for a belief does not transmit to some of that belief's logical consequences. Critics of Dretske dispute the argument against closure while joining Dretske in writing off transmission. This paper shows that, in the most widely accepted system for counterfactual logic , conclusive reasons are governed by an informative, non-trivial, logical transmission principle. If r is a conclusive reason for believing p in (...) Dretske's sense, and if p logically implies q, and if p and q satisfy one additional condition, it follows that r is a conclusive reason for believing q. After introducing this additional condition, I explain its intuitive import and use the condition to shed new light on Dretske's response to scepticism, as well as on his distinction between the so-called ‘lightweight’ and ‘heavyweight’ implications of a piece of perceptual knowledge. (shrink)

The paper articulates a novel strategy against external world skepticism. It shows that a modal assumption of the skeptical argument cannot be justified.

“Real knowledge,” as I use the term, is the most highly prized form of true belief sought by an epistemic agent. This paper argues that defeasible infinitism provides a good way to characterize real knowledge and it shows how real knowledge can arise from fallible justification. Then, I argue that there are two ways of interpreting Ernest Sosa's account of real knowledge as belief that is aptly formed and capable of being fully defended. On the one hand, if beliefs are (...) aptly formed only if they have a specific causal etiology, namely that they are efficiently caused fully or partially by virtuous characteristics of the epistemic agent, then Sosa's account falls prey to what I call the problem of the Hazard of Empirical Disconfirmation. The HED problem applies to all forms of causal accounts of real knowledge and is simply that as we gain more empirical knowledge about the causal origins of our true beliefs that are the most highly prized we will discover that they do not always satisfy the required efficient causal constraints. Bluntly put, having sufficiently good reasons for our beliefs might not require that the beliefs have the requisite efficient causal etiology. On the other hand, there is a way of interpreting Sosa's views that does not include an efficient causal prerequisite. That interpretation makes Sosa's account of real knowledge almost identical to defeasible infinitism but expressed in an alternate vocabulary. Such a view is not subject to the HED problem and it can solve the deep problem in epistemology, namely how to get epistemically certain knowledge from fallible justification. (shrink)

The problem of induction and the problem of Cartesian/brain-in-the-vat skepticism have much in common. Both are instances of a general problem of defeasible justification . I use the term "defeasible justification" to refer to a relation between a piece of evidence.

The contextualist epistemological theories proposed by David Lewis and othersoffer a view of knowledge which awards a central role to the contexts ofknowledge attributions. Such contexts are held to determine how strong anepistemic position must be in order to count as knowledge. Lewis has suggestedthat contextualism so construed can be used both to ward off the skeptic and tosolve the Gettier problem. A person knows P, he says, just in case her evidenceeliminates every possibility that not-P, where the domain of (...) `every' is determinedby the context. Lewis provides a list of rules that can tell us, for a given context,which not-P possibilities must be eliminated and which can properly be ignored.But his account entails, counterintuitively, that knowledge can truly be attributedeven to a person in a Gettier situation provided only that the attributor is ignorantof the fact that the person is gettiered. It has been criticized on those grounds byS. Cohen. In this paper I shall argue that most other forms of contextualism sufferthe same fate as Lewis's. The allies of contextualism haven't yet shown us whethercontextualism can succeed in maintaining a notion of ordinary knowledge whileresisting the absurdity that knowledge can be a matter of sheer good luck. At theend of the paper I shall suggest a possible solution to the problem by showing howCohen's line of criticism leads to a modified conception of what sort of justificationa belief must have to count as knowledge in ordinary contexts. (shrink)

(revisions posted 12/5/2006) to appear in Internalism and Externalism in Semantics and Epistemology, ed. by Sanford Goldberg (to be published by Oxford in 2006 or 2007) Michael McKinsey formulated an argument that raises a puzzle about the relation between externalism about content and our introspective awareness of content. The puzzle goes like this: it seems like I can know the contents of my thoughts by introspection alone; but philosophical reflection tells me that the contents of those thoughts are externalist, and (...) so I couldn. (shrink)

This paper examines the relationship between perceptual knowledge and discrimination in the light of the so-called ‘relevant alternatives’ intuition. It begins by outlining an intuitive relevant alternatives account of perceptual knowledge which incorporates the insight that there is a close connection between perceptual knowledge and the possession of relevant discriminatory abilities. It is argued, however, that in order to resolve certain problems that face this view, it is essential to recognise an important distinction between favouring and discriminating epistemic support that (...) is often overlooked in the literature. This distinction complicates the story regarding how an alternative becomes relevant, and in doing so weakens the connection between perceptual knowledge and discrimination. The theory that results, however—what I term a ‘two-tiered’ relevant alternatives theory of perceptual knowledge—accommodates many of our intuitions about perceptual knowledge and so avoids the revisionism of some recent proposals in the epistemological literature. (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)

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)