Sceptical arguments in epistemology typically employ sceptical hypotheses, which are rivals to our everyday beliefs so constructed that they fit exactly the evidence on which those beliefs are based. There are two ways of using a sceptical hypothesis to undermine an everyday belief, giving rise to two distinct sorts of sceptical argument: underdetermination‐based and closure‐based. However, both sorts of argument, as usually formulated in the literature, fall foul of evidential holism, for they ignore the crucial role of background beliefs. An (...) analogy with the philosophy of science makes this point explicit. There is no simple way to “holism proof” the two sceptical arguments. (shrink)

The aim of this paper is to analyse and develop how scepticism becomes an intelligible question starting from requirements that epistemologists themselves aim to endorse. We argue for and defend the idea that the root of scepticism is the underdetermination principle by articulating its specificitya respectable epistemic principle and by defending it against objections in current literature. This engagement offers a novel understanding of underdetermination-based scepticism. While most anti-sceptical approaches challenge scepticism by understanding it as postulating uneliminated scenarios of mass (...) deception, or as endorsing unnatural epistemic requirements, we argue here that both contentions are mistaken. Underdetermination-based scepticism targets our beliefs by issuing a genuine question about the rational support they enjoy. If we cannot establish that the sources of our beliefs provide them the required epistemic merit and authority, they lack non-arbitrary grounds. This has a sizable impact on what constitutes a satisfactory anti-sceptical strategy. Strategies that merely focus on the scenario-based aspect of scepticism, or on the truth-functional evaluation of our beliefs, are shown to miss the mark of the sceptical threat. The proposed analysis ultimately provides a shift in perspective concerning the character and reach of philosophical doubt. (shrink)

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)

The Cartesian arguments for external world skepticism are usually considered to be significant for at least two reasons: they seem to present genuine paradoxes and that providing an adequate response to these arguments would reveal something epistemically important about knowledge, justification, and/or our epistemic position to the world. Using only premises and reasoning the skeptic accepts, I will show that the most common Cartesian argument for external world skepticism leads to a previously unrecognized self-undermining dilemma: it either leads to a (...) reductio ad absurdum, or to avoid this reductio the skeptic must accept that this argument is epistemically idle—it does not provide any support for external world skepticism. Either way, this Cartesian argument cannot legitimately threaten or even call into question our beliefs about the external world. And thus, either way, this Cartesian argument for external world skepticism is not epistemically significant—it is not a genuine paradox and adequately responding to it need not reveal anything epistemically important. (shrink)

Responses to skeptical arguments need to be _serious_: they need to explain not only why some premise of the argument is false, but also why the premise is _plausible_, despite being false. Moorean responses to skeptical arguments are inadequate because they are not serious: they do not explain the plausibility of false skeptical premises (Sects. 2–3). Skeptical arguments presuppose the truth of the following two claims: the requirements for epistemic justification are internalist, and these internalist requirements are never satisfied (with (...) respect to our beliefs about the external world). In this paper, I provide a serious response to the skeptic on behalf of the internalist: I explain why the claim that internalist requirements are never satisfied is plausible but false. First, I argue that the claim is plausible, but only insofar as one lacks an account of how perceptual experiences make it rational to hold beliefs about the external world (and the skeptic does lack such an account) (Sect. 4). Second, I provide such an account of experiential rationality, and I argue that in light of this account John McDowell can be understood as persuasively arguing that the claim that internalist requirements are never satisfied is false (Sects. 5–6). (shrink)

According to epistemological disjunctivism (ED), in paradigmatic cases of perceptual knowledge, a subject, S, has perceptual knowledge that p in virtue of being in possession of reasons for her belief that p which are both factive and reflectively accessible to S. It has been argued that ED is better placed than both knowledge internalism and knowledge externalism to undercut underdetermination-based skepticism. I identify several principles that must be true if ED is to be uniquely placed to attain this goal. After (...) that, I use those principles to formulate a diachronic skeptical argument. This argument yields the counterintuitive conclusion that understanding a global skeptical hypothesis is all it takes for a rational subject to lose all her perceptual knowledge of the world. Next, I show that a popular Austinian move must reject one or another of the principles that underlie ED. I close by delineating a novel strategy that can block the diachronic skeptical argument while preserving all the principles. The key idea is that perceptual knowledge is grounded in primitive, perceptual and recognitional abilities. This view sheds new light on some puzzling features of global skepticism that have been noted by Descartes and Hume, among others. (shrink)

In this essay I defend a solution to a skeptical paradox. The paradox I focus on concerns epistemic justification (rather than knowledge), and skeptical scenarios that entail that most of our ordinary beliefs about the external world are false. This familiar skeptical paradox hinges on a “closure” principle. The solution is to restrict closure, despite its first appearing as a fully general principle, so that it can no longer give rise to the paradox. This has some extra advantages. First, it (...) suggests a general strategy that provides solutions to other versions of the paradox, not just those that depend on closure. Second, it clarifies the relation between the paradox and other kinds of skeptical problem. (shrink)

The problem of skepticism is often understood as a paradox: a valid argument with plausible premises whose conclusion is that we lack justification for perceptual beliefs. Typically, this conclusion is deemed unacceptable, so a theory is offered that posits conditions for justification on which some premise is false. The theory defended here is more general, and explains why the paradox arises in the first place. Like Strawson’s (Introduction to logical theory, Wiley, New York, 1952) “ordinary language” approach to induction, the (...) theory posits something built into the very notion of justification: it is loaded with a bias towards the proposition that we are not massively deceived. Beyond the paradox, remaining skeptical problems consist of metaphysical and practical questions: whether we are massively deceived, or why we should use our loaded notion rather than some other. Such challenges have profound epistemological significance, but they are not problems that an a priori theory of justification can solve. (shrink)

In this paper, I offer reasons for thinking that two prominent sceptical arguments in the literature – the underdetermination-based sceptical argument and the closure-based sceptical argument – are less philosophically interesting than is commonly supposed. The underdetermination-based argument begs the question against a non-sceptic and can be dismissed with little fanfare. The closure-based argument, though perhaps not question-begging per se, does rest upon contentious assumptions that a non-sceptic is under no pressure to accept.

Metaethical Mooreanism is the view that without being able to explain how we know certain moral claims we can nevertheless be sure that we do know them. In this paper I focus on the Moorean argument against moral error theory. I conclude that it fails. To show this failure, I first distinguish Moorean claims from Moorean arguments, and then so-called presumptive support from dialogical support. With these distinctions in place, I argue that the key Moorean claim requires dialogical support in (...) order to be used within the Moorean argument against moral error theory, but metaethical Mooreans have only provided presumptive support for the Moorean claim. Not only is this presumptive support inadequate for fending off the moral error theory, it is doubtful that Mooreans can actually provide dialogical support for the key Moorean claim. (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)

Half a century later, a Dretskean stance on epistemic closure remains a minority view. Why? Mainly because critics have successfully poked holes in the epistemologies on which closure fails. However, none of the familiar pro-closure moves works against the counterexamples on display here. It is argued that these counterexamples pose the following dilemma: either accept that epistemic closure principles are false, and steal the thunder from those who attack classical logic on the basis of similarly problematic cases—specifically, relevance logicians and (...) like-minded philosophers—or stick with closure and surrender to relevantist claims of failure in truth-preservation aimed at classical rules of inference. Classicist closure advocates find the promise of a way out of the dilemma in the works of Roy Sorensen and John Hawthorne. The paper argues against their pro-closure move and renews Robert Audi’s call for a theory of closure-failure. (shrink)

A common response to radical skeptical challenges to our knowledge of the external world has been that there are explanatory reasons (e.g., simplicity, coherence, explanatory power, conservatism) for favoring commonsense explanations of our sensory experiences over skeptical explanations. Despite the degree of visibility this class of response has enjoyed, it has often been viewed with skepticism [sic] by the epistemological community because of concerns about the epistemic merits of explanatory reasoning. I argue that skeptical challenges that employ skeptical hypotheses presuppose (...) central explanationist tenets and that this fact should raise one’s estimation of the strength of explanationist responses to skepticism. (shrink)

The paper defends Cartesian skepticism by an argument relying on internalism and infallibilism. It argues that this sort of skepticism gives the best explanation of our intuitions and ordinary epistemic practices.

Contemporary discussions of epistemological skepticism - the view that we do not and cannot know anything about the world around us - focus very much on a certain kind of skeptical argument involving a skeptical scenario (a situation familiar from Descartes’ First Meditation). According to the argument, knowing some ordinary proposition about the world (one we usually take ourselves to know) requires knowing we are not in some such skeptical scenario SK; however, since we cannot know that we are not (...) in SK we also cannot know any ordinary proposition. One of the most prominent skeptical scenarios is the brain-in-the-vat-scenario: An evil scientist has operated on an unsuspecting subject, removed the subject’s brain and put it in a vat where it is kept functioning and is connected to some computer which feeds the brain the illusion that everything is “normal”. This paper looks at one aspect of this scenario after another – envatment, disembodiment, weird cognitive processes, lack of the right kind of epistemic standing, and systematic deception. The conclusion is that none of these aspects (in isolation or in combination) is of any relevance for a would-be skeptical argument; the brain-in-the-vat-scenario is irrelevant to and useless for skeptical purposes. Given that related scenarios (e.g., involving evil demons) share the defects of the brain-in-the-vat-scenario, the skeptic should not put any hopes on Cartesian topoi. (shrink)

Epistemological disjunctivism is a philosophical theory that has received special attention in the recent years. Particularly because it has been seen by many as a way of renewing discussions that range from the nature of justification of our daily beliefs to the possibility of unveiling the structure of the problem of radical skepticism and of responding to it. Duncan Pritchard is one of the authors who have offered a particular view of disjunctivism and ways of conceiving of disjunctivist treatments to (...) such questions. His work has as its main source of inspiration the seminal work of John McDowell. In this paper, I present a way of understanding the problem ofradicalskepticism and the mannerin which epistemological disjunctivism aimsto offer solutionsto it. In orderto do that, I present McDowell’s general proposal and discuss in which way his account differs from Pritchard’s own disjunctivism. At the end, I try to show how Pritchard’s approach tries to respond to radical skepticism not only by appealing to a disjunctivist reading of our epistemic position, but also by offering a revision of our structure of reasons. (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)

_ 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)

Putnam’s vat argument is intended to show that I am not a permanently envatted brain. The argument holds promise as a response to vat scepticism, which depends on the claim that I do not know that I am not a permanently envatted brain. However, there is a widespread idea that the vat argument cannot fulfil this promise, because to employ the argument as a response to vat scepticism I would have to make assumptions about the content of the premises and/or (...) conclusion of the argument that beg the question against the sceptic. In this paper, I show that this idea is mistaken. (shrink)

Conceptual Engineering alleges that philosophical problems are best treated via revising or replacing our concepts (or words). The goal here is not to defend Conceptual Engineering but rather show that it can (and should) invoke Neutralism—the broad view that philosophical progress can take place when (and sometimes only when) a thoroughly neutral, non-specific theory, treatment, or methodology is adopted. A neutralist treatment of one form of skepticism is used as a case study and is compared with various non-neutral rivals. Along (...) the way, a new taxonomy for paradox is proposed. (shrink)

Doris argues that our choices are heavily influenced by forces that we wouldn’t count as genuine reasons. This unsettling conclusion is motivated by a debunking argument so wide-ranging that it isn’t foisted upon us by the sciences. Doris sometimes seems to lower his ambitions when offering instead a skeptical hypothesis argument, but that conflicts with his aims in the book.

_ Source: _Volume 7, Issue 2, pp 69 - 90 It is often claimed that, as a result of scientific progress, we now _know_ that the natural world displays no design. Although we have no interest in defending design hypotheses, we will argue that establishing claims to the effect that we know the denials of design hypotheses is more difficult than it seems. We do so by issuing two skeptical challenges to design-deniers. The first challenge draws inspiration from radical skepticism (...) and shows how design claims are at least as compelling as radical skeptical scenarios in undermining knowledge claims, and in fact probably more so. The second challenge takes its cue from skeptical theism and shows how we are typically not in an epistemic position to rule out design. (shrink)

We report the results of four empirical studies designed to investigate the extent to which an epistemic closure principle for knowledge is reflected in folk epistemology. Previous work by Turri (2015a) suggested that our shared epistemic practices may only include a source-relative closure principle—one that applies to perceptual beliefs but not to inferential beliefs. We argue that the results of our studies provide reason for thinking that individuals are making a performance error when their knowledge attributions and denials conflict with (...) the closure principle. When we used research materials that overcome what we think are difficulties with Turri’s original materials, we found that participants did not reject closure. Furthermore, when we presented Turri’s original materials to non-philosophers with expertise in deductive reasoning (viz., professional mathematicians), they endorsed closure for both perceptual and inferential beliefs. Our results suggest that an unrestricted closure principle—one that applies to all beliefs, regardless of their source—provides a better model of folk patterns of knowledge attribution than a source-relative closure principle. (shrink)

Support is canvassed for a novel solution to the sceptical problem regarding our knowledge of the external world. Key to this solution is the claim that what initially looks like a single problem is in fact two logically distinct problems. In particular, there are two putative sceptical paradoxes in play here, which each trade on distinctive epistemological theses. It is argued that the ideal solution to radical scepticism would thus be a biscopic proposal—viz., a two-pronged, integrated, undercutting treatment of both (...) putative sceptical paradoxes. A particular biscopic proposal is then explored which brings together two apparently opposing anti-sceptical theses: he Wittgensteinian account of the structure of rational evaluation and epistemological disjunctivism. It is argued that each proposal enables us to gain a purchase on one, but only one, aspect of the two-sided sceptical problem. Furthermore, it is argued that these proposals are not only compatible positions, but also mutually supporting and advanced in the same undercutting spirit. A potential cure is thus offered for epistemic angst. (shrink)

I use some ideas of Keith DeRose's to develop an (invariantist!) account of why sceptical reasoning doesn't show that I don't know that I'm not a brain in a vat. I argue that knowledge is subject to the risk-of-error constraint: a true belief won’t have the status of knowledge if there is a substantial risk of the belief being in error that hasn’t been brought under control. When a substantial risk of error is present (i.e. beliefs in propositions that are (...) false in nearby worlds), satisfying the constraint requires bringing the risk under control. This is achieved either by sensitivity, i.e. you wouldn’t have the belief if it were false, or by identifying evidence for the proposition. However, when the risk of error is not substantial (i.e. beliefs in propositions that are not false in nearby worlds), the constraint is satisfied by default. My belief that I am not a brain in a vat is insensitive and I have no evidence for it, but since it is not false in nearby worlds, it satisfies the constraint by default. (shrink)

I first argue that the skeptic needs an internalist conception of justification for her argument for skepticism. I then argue that the skeptic also needs to show that we do not have perceptual access to the world if her skepticism is to be a real threat to human knowledge of the world. This, I conclude, puts the skeptic in a dilemma, for internalist conceptions of justification presuppose that we have perceptual access to the world.

The Mundane World Hypothesis (mwh) says that we have material bodies, we have brains located inside our bodies, we have sense organs which process visual information, the direct cause of our perceptual judgments is typically macroscopic material objects, and we live in a material world. Skeptics using underdetermination arguments arguemwhhas no more epistemic merit than some skeptical competitor, e.g., that we are in the Matrix. Since such competitor hypotheses are equipollent, we are not justified in believingmwh. This paper takes the (...) underdetermination skeptic’s premises to a more radical conclusion: skeptical dogmatism, which is the view thatmwhis probably false based on the idea that there are many equipollent competitors tomwh. (shrink)

This paper considers two novel Bayesian responses to a well-known skeptical paradox. The paradox consists of three intuitions: first, given appropriate sense experience, we have justification for accepting the relevant proposition about the external world; second, we have justification for expanding the body of accepted propositions through known entailment; third, we do not have justification for accepting that we are not disembodied souls in an immaterial world deceived by an evil demon. The first response we consider rejects the third intuition (...) and proposes an explanation of why we have a faulty intuition. The second response, which we favor, accommodates all three intuitions; it reconciles the first and the third intuition by the dual component model of justification, and defends the second intuition by distinguishing two principles of epistemic closure. (shrink)

The topic of the dissertation is this: How well does contextualism, in general, fare as an epistemic theory? And the answer comes in three parts. The root of the skeptical problem. I argue that the source of the skeptical problem is neither the underdetermination principle nor the closure principle. Instead, I claim that it is a change in context that generates the problem in the first place. Though I make no explicit argument in favor of contextualism as a solution to (...) skeptical problems, the chapter amounts to a de facto defense of the contextualist solution to skeptical problems. The problem with Gettier. I consider criticisms of contextualism's capacity to resolve Gettier cases. As it stands, Lewis' contextualism can't resolve a wide range of Gettier cases. However, I offer a new rule, the Rule of Special Similarity, as a replacement rule for Lewis' Rule of Resemblance. I then show how the new rule, though not problem-free, can do a much better job of resolving the Gettier problem. Contextualism, then, needn't fail because it can't solve Gettier problems; it can. The ways of context. One goal is to get a clear map of the territory, one that underscores the fact that precisely how context is incorporated into the theory matters epistemically. Another is to make the point that contextualism—the claim that context plays an essential semantic role in knowledge ascriptions—is not just one particular view, but a family of similar views. Also, I offer a new kind of contextualism that avoids many of the substantial criticisms aimed at the others in the family. Though the primary aim of the dissertation is a defense in three parts of the contextualist approach I general, a view emerges from the dissertation. I call the view condexicalism, and the dissertation is, secondarily, a development and defense of that view. (shrink)

In this paper I develop an account of petitio principii (the fallacy sometimes also called ‘vicious circularity’, or ‘begging the question’) which has two crucial features: it employs the notion of doxastic justification, and it takes circularity to be relative to an evidential state. According to my account, an argument will be circular relative to an evidential state if and only if having doxastic justification for the conclusion is necessary, for a subject in that evidential state, to have doxastic justification (...) for the premisses. I compare the account to some existing ones, and claim some advantages. I then rebut an objection which threatens to undermine the importance of one of those advantages. This account seems to shed new light on the old problem of characterizing petitio principii. It avoids the two obvious problems which any account of this phenomenon must face: being too narrow, for example by leaving out all arguments in which the conclusion does not appear among the premisses, and being too wide, making all valid arguments circular. (shrink)

Moral skeptics maintain that we do not have moral knowledge. Traditionally they haven’t argued via skeptical hypotheses like those provided by perceptual skeptics about the external world, such as Descartes’ deceiving demon. But some believe this can be done by appealing to hypotheses like moral nihilism. Moreover, some claim that skeptical hypotheses have special force in the moral case. But I argue that skeptics have failed to specify an adequate skeptical scenario, which reveals a general lesson: such arguments are not (...) a promising avenue for moral skeptics to take. They’re ultimately weaker when applied to morality compared to perception. (shrink)

Anthony Brueckner has argued that claims about underdetermination of evidence are suppressed in closure-based scepticism (“The Structure of the Skeptical Argument”, Philosophy and Phenomenological Research 54:4, 1994). He also argues that these claims about underdetermination themselves lead to a paradoxical sceptical argument—the underdetermination argument—which is more fundamental than the closure argument. If Brueckner is right, the status quo focus of some predominant anti-sceptical strategies may be misguided. In this paper I focus specifically on the relationship between these two arguments. I (...) provide support for Brueckner’s claim that the underdetermination argument is the more fundamental sceptical argument. I do so by responding to a challenge to this claim put forward by Stewart Cohen (“Two Kinds of Skeptical Argument”, Philosophy and Phenomenological Research 58:1, 1998). Cohen invokes an alternative epistemic principle which he thinks can be used to challenge Brueckner. Cohen’s principle raises interesting questions about the relationship between evidential considerations and explanatory considerations in the context of scepticism about our knowledge of the external world. I explore these questions in my defence of Brueckner. (shrink)

On a common view of scenario-based sceptical arguments sceptical scenarios are error-possibilities, i.e. their point is to introduce the possibility of having only false beliefs. However, global error is impossible for purely logical/conceptual reasons: Even if one’s beliefs are consistent, the negations of one’s beliefs need not be consistent as well. My paper deals with the question of what the consequences of this result are. Two attempts at repairing scenario-based sceptical arguments within the framework of understanding sceptical scenarios as error-possibilities (...) are found wanting. Instead, what should be given up is the assumption that sceptical scenarios are error-possibilities. What is thought-provoking about the scenario of the brain in a vat is not that none of its empirical beliefs are true, but that all of its empirical beliefs fall short of knowledge at the same time. Hence, sceptical scenarios are not error-possibilities, but ignorance possibilities. If this is so, both the closure argument and the underdetermination argument commit a subtle mistake and should be replaced by slightly different arguments. The principle of excluded ignorance-possibilities turns out to be an epistemological principle that is faithful to scepticism’s tenets without misinterpreting sceptical scenarios as error-possibilities. (shrink)

I focus on a key argument for global external world scepticism resting on the underdetermination thesis: the argument according to which we cannot know any proposition about our physical environment because sense evidence for it equally justifies some sceptical alternative (e.g. the Cartesian demon conjecture). I contend that the underdetermination argument can go through only if the controversial thesis that conceivability is per se a source of evidence for metaphysical possibility is true. I also suggest a reason to doubt that (...) conceivability is per se a source of evidence for metaphysical possibility, and thus to doubt the underdetermination argument. (shrink)

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)

Some philosophers argue that we are justified in rejecting skepticism because it is explanatorily inferior to more commonsense hypotheses about the world. Focusing on the work of Jonathan Vogel, I show that this “abductivist” or “inference to the best explanation” response rests on an impoverished explanatory framework which ignores the explanatory gap between an object's having certain properties and its appearing to have those properties. Once this gap is appreciated, I argue, the abductivist strategy is defeated.

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.

Abductivists claim that explanatory considerations (e.g., simplicity, parsimony, explanatory breadth, etc.) favor belief in the external world over skeptical hypotheses involving evil demons and brains in vats. After showing how most versions of abductivism succumb fairly easily to obvious and fatal objections, I explain how rationalist versions of abductivism can avoid these difficulties. I then discuss the most pressing challenges facing abductivist appeals to the a priori and offer suggestions on how to overcome them.

Anthony Brueckner argues for a strong connection between the closure and the underdetermination argument for scepticism. Moreover, he claims that both arguments rest on infallibilism: In order to motivate the premises of the arguments, the sceptic has to refer to an infallibility principle. If this were true, fallibilists would be right in not taking the problems posed by these sceptical arguments seriously. As many epistemologists are sympathetic to fallibilism, this would be a very interesting result. However, in this paper I (...) will argue that Brueckner’s claims are wrong: The closure and the underdetermination argument are not as closely related as he assumes and neither rests on infallibilism. Thus even a fallibilist should take these arguments to raise serious problems that must be dealt with somehow. (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)

It is nowadays taken for granted that the core radical sceptical arguments all pivot upon the principle that the epistemic operator in question is 'closed' under known entailments. Accordingly, the standard anti-sceptical project now involves either denying closure or retaining closure by amending how one understands other elements of the sceptical argument. However, there are epistemic principles available to the sceptic which are logically weaker than closure but achieve the same result. Accordingly the contemporary debate fails to engage with the (...) sceptical problem in its strongest form. (shrink)

Cartesian skepticism about epistemic justification (‘skepticism’) is the view that many of our beliefs about the external world – e.g., my current belief that I have hands – aren’t justified. I examine the two most influential arguments for skepticism – the Closure Argument and the Underdetermination Argument – from an evidentialist perspective. For both arguments it is clear which premise the anti-skeptic must deny. The Closure Argument, I argue, is the better argument in that its key premise is weaker than (...) the Underdetermination Argument’s key premise. However, it’s also likely that the motivation for accepting both key premises is exactly the same. So there may be a sense in which both arguments provide exactly the same motivation for skepticism. Then I argue that if I I’m right about what the motivation for accepting the arguments’ key premises is, then neither argument succeeds in providing a good reason to accept skepticism. I conclude by explaining why I think epistemologists are right to expend a lot of time and effort on refuting these arguments, even if neither argument provides any motivation for skepticism. (shrink)

The author argues that is not obvious what it means for our beliefs and assertions to be "truth-directed", and that we need to weaken our ordinary notion of a belief if we are to deal with radical scepticism without surrendering to idealism. Topics examined also include whether there could be alien conceptual schemes and what might happen to us if we abandoned genuine belief in place of mere pragmatic acceptance. A radically new "ecological" model of knowledge is defended.

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)

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)