Radical scepticism contends that our knowledge of the external world is impossible. Particularly, radical scepticism can be motivated by the closure principle. Several commentators have noted that a straightforward way to respond to such arguments is via externalist strategies, e.g., Goldman, Greco, Bergmann. However, these externalist strategies are not effective against a slightly weaker form of the argument, a closure principle for rationally grounded knowledge, closureRK.\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${closure}_{RK.}$$\end{document} The sceptical argument, framed around the (...) closureRK\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {closure}_{\mathrm{RK}}$$\end{document} principle, targets rationally grounded knowledge. Although externalist strategies are ineffective against this form of argument, its conclusion can nonetheless be resisted by combining, in a novel way, the resources of Wittgenstein and Davidson. In particular, I argue that the sceptic is assuming an unrestricted way of using the closureRK\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {closure}_{\mathrm{RK}}$$\end{document} principle, which is incorrect. Alternatively, I argue for The Conditionality of Rational Support Thesis, i.e., the thesis that rational support via competent deduction is conditional. In particular, rational support must be provided within an evaluative system in which hinge propositions are presupposed and contentful beliefs are being evaluated. In the end, we can resist the closureRK\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {closure}_{\mathrm{RK }}$$\end{document}-based sceptical argument while retaining the closureRK\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {closure}_{\mathrm{RK}}$$\end{document} principle. (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)

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)

In contemporary epistemology, sceptical arguments are motivated either by the closure principle or the underdetermination principle. Therefore, it is very important to figure out the structure of the sceptical argument before coming up with an anti-sceptic strategy. With a review of the debate on the relationship between the two principles from Anthony Brueckner to Kevin McCain, it is argued that while maintaining the weak closed justification , closure and underdetermination are not logically equivalent. As a result, two independent responses are (...) needed to answer the sceptical problem satisfactorily. Also, in order to secure a philosophically significant notion of justification and evidence, reasons are given to hold WCJ*, as opposed to rejecting it. This understanding of the sceptical argument would help to focus the real challenge of scepticism. (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)

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)

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.

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.

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)

Does G. E. Moore know that he has hands? Yes, says the dogmatist: Moore’s hands are right before his eyes. No, says the skeptic: for all Moore knows he could be a brain-in-a-vat. Yes and no, says the contrastivist: yes, Moore knows that he has hands rather than stumps; but no, Moore does not know that he has hands rather than vat-images of hands. The dogmatist and the skeptic suppose that knowledge is a binary, categorical relation: s knows that p. (...) The contrastivist says that knowledge is a ternary, contrastive relation: s knows that p rather than q. (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 MODERATISM, perceptual justification requires that one independently takes for granted propositional hinges like <There is an external world>, <I am not a brain in a vat (BIV)>, and so on. This view faces the truth problem: to offer an account of truth for hinges that is not threatened by skepticism. Annalisa Coliva has tried to solve the truth problem by combining the claim that external world propositions have a substantive truth property like correspondence with the claim that hinges (...) have a deflationary truth property. I argue that the resulting view cannot offer a coherent characterization of ‘skeptical switch scenarios’ while providing an effective anti-skeptical strategy. In a more positive vein, I defend an approach that combines a correspondence conception of truth with epistemological disjunctivism. (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)

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)

Deepfakes are audio, video, or still-image digital artifacts created by the use of artificial intelligence technology, as opposed to traditional means of recording. Because deepfakes can look and sound much like genuine digital recordings, they have entered the popular imagination as sources of serious epistemic problems for us, as we attempt to navigate the increasingly treacherous digital information environment of the internet. In this paper, I attempt to clarify what epistemic problems deepfakes pose and why they pose these problems, by (...) drawing parallels between recordings and our own senses as sources of evidence. I show that deepfakes threaten to undermine the status of digital recordings as evidence. The existence of deepfakes thus encourages a kind of skepticism about digital recordings that bears important similarities to classic philosophical skepticism concerning the senses. However, the skepticism concerning digital recordings that deepfakes motivate is also importantly different from classical skepticism concerning the senses, and I argue that these differences illuminate some possible strategies for solving the epistemic problems posed by deepfakes. (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)

Philosophical skepticism about the external world seeks to call into question our knowledge of the external world. Some kinds of philosophical skepticism employ skeptical hypotheses to prove that we cannot know anything about the external world. Putnam tried to refute this kind of skepticism by adopting semantic externalism; but, as is now generally accepted, Putnam’s argument is epistemically circular. Brueckner proposes some new, “simple” arguments that in his view are not circular. In this paper we evaluate Brueckner’s simple arguments for (...) refuting skepticism about the external world, and seek to demonstrate that they fail to prove that we can have knowledge about the external world. However, by appeal to the principle of privileged access, one of the Brueckner’s arguments does indeed succeed in showing that we can have justified beliefs about the external world. (shrink)

It is claimed that the radical sceptical problem that is the focus of much of contemporary epistemological discussion in fact divides into two logically distinct subproblems --a formulation that turns on the closure principle, and a second formulation which turns on the underdetermination principle. The Wittgensteinian account of the structure of rational evaluation is set out, and it is shown how this proposal --at least when properly formulated--can deal with closure-based radical scepticism. It is also claimed, however, that this account (...) fails to gain any purchase on underdetermination-based radical scepticism. The antidote to this latter form of radical scepticism lies elsewhere--with, it is suggested, epistemological disjunctivism. (shrink)

The purpose of this paper is to provide a new solution to the radical sceptical paradox. A sceptical paradox purports to indicate the inconsistency within our fundamental epistemological commitments that are all seemingly plausible. Typically, sceptics employ an intuitively appealing epistemic principle (e.g., the closure principle, the underdetermination principle) to derive the sceptical conclusion. This paper will reveal a dilemma intrinsic to the sceptical paradox, which I refer to as the self-hollowing problem of radical scepticism. That is, on the one (...) hand, if the sceptical conclusion turns out to be true, then the epistemic principle employed by sceptics would lose its foundation of plausibility; on the other hand, if the sceptical conclusion does not follow, then the sceptical problem would not arise. In either case, the so-called sceptical paradox cannot be a genuine paradox. This new solution has three theoretical merits: it is undercutting, less theory-laden, and widely applicable. (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 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 pro- found epistemological significance, but they are not problems that an a priori theory of justification can solve. (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.

_ 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)

The epistemological problem of the external world asks: (1) “How is knowledge of the external world possible given certain obstacles which make it look impossible?” This is a “how-possible?” question: it asks how something is possible given certain obstacles which make it look impossible (cf. Cassam 2007; Nozick 1981; Stroud 1984). Now consider the following question, which asks: (2) “How is a philosophically satisfying answer to (1) possible?” Skepticism is the thesis that knowledge of the external world is impossible. It (...) therefore represents a negative answer to the first question. Meta-epistemological skepticism is the thesis that a satisfying philosophical explanation of how our knowledge of the external world is possible is itself impossible. It therefore represents a negative answer to the second question. In this thesis, I explore the prospects of meta-epistemological skepticism. In particular, I structure the thesis around two master arguments from for meta-epistemological skepticism. The first argument is that skepticism represents a kind of paradox which requires dispensing with a plausible principle or belief, or even 'platitude', which means that there's no philosophically satisfying response to the paradox (see, e.g., Stroud 1984), and the second argument is “Stroud’s dilemma” (cf. Cassam 2009), that either we explain how external world knowledge is possible by reference to what external world knowledge we have, thereby failing to answer the philosophical question adequately, or else we don't, but then we succumb to first-order skepticism. I argue that the first argument fails to provide adequate support for meta-epistemological skepticism. However, the second argument, Stroud’s dilemma, is plausible and withstands serious objections (e.g., from Sosa 1994, Williams 1996, and Cassam 2009). In short, while the worry emerging out of the 'skeptical paradox' view fails to adequately support meta-epistemological skepticism, Stroud’s dilemma succeeds. Fortunately, it doesn't show that we lack external world knowledge; we rather just can't explain, philosophically, how it's possible. We may have first-order knowledge without understanding how it's possible. This thesis therefore represents a partial defense of meta-epistemological skepticism. Meta-epistemological skepticism is a live option in epistemology. (shrink)

Epistemic contextualists like David Lewis allow that we have substantially infallibilist reflective intuitions about knowledge even though our everyday talk accepts fallibilist attributions of knowledge. They give serious weight to both our everyday talk and our propensity to assent to the skeptic's conclusions, and give us a concept of knowledge that accommodates both. The skeptic would, of course, leverage such infallibilist intuitions in order to undermine the legitimacy of our everyday attributions. Most contemporary epistemologists would simply argue that our concept (...) of knowledge is fallibilist, but this doesn't give them a particularly convincing reply to intuitively compelling skeptical arguments. ;This essay, most generally, takes up the question of how best to argue about skepticism. I claim that a philosophical account of knowledge that responds to skepticism should be able to clearly accommodate our epistemic agency. In chapter 1 I explain how skepticism challenges our naIve conception of agency and introduce two criteria for an adequate response to skepticism. In chapter 2, I discuss contextualist solutions; I argue they fail to satisfy our criteria and fail on their own terms; I explain how both failures relate to a failure to adequately treat epistemic agency. In chapter 3 I develop a conception of epistemic agency that describes what it is to be an active, reasoning source of belief. This picture is at odds with a dominant strain of epistemology that has it that one is substantially subject to belief, not effectively responsible for it; I criticize an influential argument by Bernard Williams that claims belief is not an attitude we control. This discussion in chapter 3 gives support to, a rationale for, the anti-insulationism requirement set out in chapter 1. Finally, in chapter 4 I return to the methodological issues of how to argue about skepticism. I first defend the idea that a knowledge-based skepticism is worth philosophical attention. I then offer an interpretation of what the skeptic is up to, and discuss what an effective counterstrategy might look like; I suggest that a particular sort of normative argument is the best way with the skeptic. (shrink)

This Introduction to the special issue on “Skepticism and Justification” provides a background to the nine articles collected here and a detailed summary of each, which highlights their interconnections and relevance to the debate at the heart of the issue.

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.

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)

The sceptic about the external world presents us with a paradox: an apparently acceptable argument for an apparently unacceptable conclusion—that we do not know anything about the external world. Some paradoxes, for instance the liar and the sorites, are very hard. The defense of a purported solution to either of these two inevitably deploys the latest in high-tech philosophical weaponry. On the other hand, some paradoxes are not at all hard, and may be resolved without much fuss. They do not (...) contain profound lessons about the human condition. Where should we place the sceptical paradoxes? (shrink)

In Radical Skepticism & Epistemic Intuition Michael Bergmann attempts to overcome the threat of radical skepticism as it arises in several different forms. The key to Bergmann’s response to skepticism is his method of intuitionist particularism wherein we give our intuitions about particular beliefs being justified more weight than we do intuitions about the premises of arguments for skepticism. There are two general problems for Bergmann’s response to skepticism. First, he fails to accurately portray the key principle of the skeptical (...) argument. As a result, much of the apparent motivation for looking to intuitionist particularism as opposed to other responses to skepticism is merely apparent. Second, intuitionist particularism faces significant problems when it comes to the Problem of the Criterion and the resolution of conflicting intuitions. However, a related intuitionist method, one incorporating explanationism, may be able to deliver what intuitionist particularism promises while avoiding its problems. (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 paper, I’ll survey a number of closure principles of epistemic justification and find them all wanting. However, it’ll be my contention that there’s a novel closure principle of epistemic justification that has the virtues of its close cousin closure principles, without their vices. This closure principle of epistemic justification can be happily thought of as a multi-premise closure principle and it cannot be used in Cartesian skeptical arguments that employ a closure principle of epistemic justification. In this way, (...) then, it represents marked improvement over other contemporary closure principles of epistemic justification that require both sacrificing multi-premise closure and forcing anti-Cartesian skeptics who reject the closure principle employed in certain Cartesian skeptical arguments to cast aside justification closure. (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)

_ 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)

Descartes’s Evil Demon argument has been the subject of many reconstructions in recent analytic debates. Some have proposed a reconstruction with a principle of Infallibility, others with a principle of Closure of Knowledge, others with more original principles. In this paper, I propose a new reconstruction, which relies on the combination of two principles, namely the Meta-Coherence principle and the principle of Closure of Justification. I argue that the argument construed in this way is the best interpretation of what is (...) really at play in the Evil Demon intuition, and also that this argument is dialectically much stronger than previous reconstructions. If this is right, then the “Closure plus Meta-Coherence” argument is what anti-sceptics should really be attacking. (shrink)

_ Source: _Page Count 29 Underdetermination arguments for skepticism maintain that our common sense view of the external world is no better, evidentially speaking, than some skeptical competitors. An important and well-known response by dogmatists, those who believe our commonsense view is justified, appeals to abduction or inference to the best explanation. The predominant version of this strategy, going back at least to Locke, invokes Occam’s razor: dogmatists claim the common sense view is simpler than any of its skeptical alternatives (...) and so has more to recommend it, evidentially speaking. This dispute has overshadowed another possible view: skeptical dogmatism. Skeptical dogmatists hold that we are justified in believing that the common sense view is probably false. I argue that skeptical dogmatism presents some interesting complications to the dialectic between the dogmatist and the skeptic. On the one hand, even if the dogmatist’s use of Occam’s razor is sufficient to rebut skepticism, in itself it is not sufficient to refute skeptical dogmatism. On the other hand, skeptics themselves, ironically, must, given the assumptions of the paper, appeal to something like Occam’s razor in order to avoid capitulating to skeptical dogmatism. (shrink)

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)

The first step in responding to the challenge of external world skepticism is to get clear on the structure of the skeptic’s argument. The most prominent varieties of skeptical arguments either rely on closure principles or underdetermination principles. The relationship between these two sorts of arguments is contentious. Some argue that these arguments can independently motivate skepticism. Others argue that they are really equivalent. I argue that although these two arguments are distinct, their independence is not as obvious as some (...) have thought. The fact that these arguments are not equivalent is important because skeptical arguments that appeal to underdetermination principles cannot be refuted by simply denying closure. So, the strategy for responding to skepticism offered by Nozick/Dretske does not seem an adequate solution. (shrink)

After providing some historical and systematic background, I introduce the structure of a very natural and influential sceptical underdetermination argument. The argument assumes that it is metaphysically possible for a deceived subject to have the same evidence that a non-deceived subject has, and tries to draw consequences about justification from that assumption of metaphysical possibility. I first variously object to the transition from the assumption to its supposed consequences. In the central part of the paper, I then critically consider some (...) influential ways of bridging the gap between the assumption and its supposed consequences, which generally consist in strengthening the assumption from one of metaphysical possibility into one of either counterfactual implication or entailment. The discussion indicates that epistemic facts are much more independent from metaphysically modal facts than the sceptical underdetermination argument requires. (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)