Laurence BonJour and more recently James Beebe have argued that the best way to defend the claim that abduction or inference to the best explanation is epistemically justified is the rationalist view that it is justified a priori. However, rationalism about abduction faces a number of challenges. This chapter focuses on one particular, highly influential objection, that there is no interpretation of probability available which is compatible with rationalism about abduction. The rationalist who wants to maintain a strong connection between (...) epistemic justification and probability would do best to rely on a Keynesian interpretation of probability. However, the latter is vulnerable to Ramsey’s famous criticism that we do not seem to perceive or be aware of such probabilities. The chapter argues that Ramsey’s criticism is unsuccessful, and that there are good reasons to be optimistic about our ability to have access to probabilities relevant to abductive inference. (shrink)

Despite decades of focused philosophical investigation, Inference to the Best Explanation still lacks a precise articulation and compelling defense. The primary reason for this is that it is not at all clear what it means for a hypothesis to be the best available explanation of the evidence. This paper first seeks to rectify this problem by developing a formal explication of the explanatory virtue of power. A resulting account of IBE is then evaluated as a form of uncertain inference. Overall, (...) this paper offers a precise account and novel defense of one important version of IBE. (shrink)

In this paper I will be setting aside contextualists and closure-deniers and focusing solely on neo-Moorean versions of externalist responses to skepticism. I will be focusing on two prominent theses about externalist responses to skepticism, one positive and one negative. The positive thesis announces an alleged virtue of externalism: that externalism alone avoids skepticism. The negative thesis identifies an alleged defect of externalism: that externalism implausibly avoids skepticism. I will be critical of both theses, though I will try to uncover (...) the truth in the neighborhood of each. I’ll close by arguing briefly that the conclusions reached in examining these two theses give us a reason to endorse externalism. (shrink)

Outside the philosophy classroom, global skeptics – skeptics about all (purported) knowledge of the external world – are rare. But there are people who describe themselves as “skeptics” about various more specific domains, including self-professed “skeptics” about the reality of anthropogenic climate change. There is little to no philosophical literature that juxtaposes the climate change skeptic with the external world skeptic. While many “traditional” epistemologists assume that the external world skeptic poses a serious philosophical challenge in a way that the (...) climate change skeptic doesn’t, many “applied” or “social” epistemologists assume that there isn’t much to be learned from debates about the external world skeptic, finding her challenge to be distant from both common sense and real-world concerns. I try to show that both of these views are mistaken. The external world skeptic raises deep questions that are important for our everyday deliberation about what to believe, and there are significant structural parallels between the arguments for external world skepticism and those for at least a form of climate change skepticism that is idealized – but not too idealized! – from the views of flesh-and-blood climate change skeptics. As such, we have strong reasons to think in parallel about how to reply to both skeptics’ challenges. I thus finish by (briefly) considering how different widespread responses to the external world skeptic might or might not generalize happily to the climate change skeptic’s challenge. (shrink)

We face reality presented with the data of conscious experience and nothing else. The project of early modern philosophy was to build a complete theory of the world from this starting point, with no cheating. Crucial to this starting point is the data of conscious sensory experience – sense data. Attempts to avoid this project often argue that the very idea of sense data is confused. But the sense-data way of talking, the sense-data language, can be freed from every blemish (...) using ideas from contemporary metaontology. We can adopt a sense-data framework that vindicates the traditional claims of sense-data theories and leads to plausible theories of perception and color. We can, we should, and in a sense, we must. Yet when we do, we face the traditional problem of external world skepticism, head-on. The real challenge of skepticism is forced upon us; it cannot honestly be avoided using externalist tricks, burden of proof shifting, or other razzle dazzle. But the challenge can be met: we are rational to posit the external world as the best explanation of the many synchronic and diachronic patterns over our sense-data. This paper argues for all of these points and ends with a plea for analytic empiricism – a traditional sense-data version of empiricism that uses all of the tools of analytic philosophy while avoiding the more questionable doctrines of the Vienna Circle (phenomenalism, verificationism). Analytic empiricism is our last best hope for completing the great philosophical project of early modern philosophy. (shrink)

Many idealists have thought that realism raises epistemological problems. The worry is that, if it is possible for truths about ordinary objects to outstrip our experiences in the ways that realists typically suppose, we could never be justified in our beliefs about objects. Few contemporary theorists find this argument convincing; philosophers have offered a variety of responses to defend the epistemology of our object judgments under the assumption of realism. But in this paper, I offer a new type of epistemic (...) argument against realism which is immune to the standard responses in the literature. In addition to raising a challenge for realism, the epistemology of our object judgments has implications for how the idealist should develop her own positive metaphysical view. So in the second half of this paper, I discuss how the idealist should understand the dependence between objects and our experiences if she is to secure epistemic advantages over the realist. (shrink)

Alexander Campbell once declared “a solemn league and covenant” between philosophy and common sense. Campbell’s pronouncement is representative of a broader trend in the Restorationist movement to look favorably on the common sense response to skepticism—a response originating in the work of Scottish philosopher and former minister Thomas Reid. I recount the tumultuous history between philosophy and common sense followed by the efforts of Campbell and Reid to reunite them. Turning to the present, I argue that an epistemic principle known (...) as phenomenal conservatism best embodies the core insights contained within Reid and Campbell's common sense response to skepticism. I finish by arguing for phenomenal conservatism. (shrink)

Extended Rationality: A Hinge Epistemology provides a novel account of the structure of epistemic justification. Its central claim builds upon Wittgenstein's idea in On Certainty that epistemic justifications hinge on some basic assumptions and that epistemic rationality extends to these very hinges. It exploits these ideas to address major problems in epistemology, such as the nature of perceptual justifications, external world skepticism, epistemic relativism, the epistemic status of basic logical laws, of the Principle of the Uniformity of Nature, of our (...) belief in the existence of the past and of other minds, and the nature of testimonial justification. Along the way, further technical issues, such as the scope of the Principle of Closure of epistemic operators under known entailment, the notion of transmission failure, and the existence of entitlements are addressed in new and illuminating ways. (shrink)

In this article, I will provide a critical overview of the form of non-deductive reasoning commonly known as “Inference to the Best Explanation” (IBE). Roughly speaking, according to IBE, we ought to infer the hypothesis that provides the best explanation of our evidence. In section 2, I survey some contemporary formulations of IBE and highlight some of its putative applications. In section 3, I distinguish IBE from C.S. Peirce’s notion of abduction. After underlining some of the essential elements of IBE, (...) the rest of the entry is organized around an examination of various problems that IBE confronts, along with some extant attempts to address these problems. In section 4, I consider the question of when a fact requires an explanation, since presumably IBE applies only in cases where some explanation is called for. In section 5, I consider the difficult question of how we ought to understand IBE in light of the fact that among philosophers, there is significant disagreement about what constitutes an explanation. In section 6, I consider different strategies for justifying the truth-conduciveness of the explanatory virtues, e.g., simplicity, unification, scope, etc., criteria which play an indispensable role in any given application of IBE. In section 7, I survey some of the most recent literature on IBE, much of which consists of investigations of the status of IBE from the standpoint of the Bayesian philosophy of science. (shrink)

I argue that the way the world appears to be plays an important role in standard scientific practice, and that therefore the way the world appears to be ought to play a similar role in metaphysics as well. I then show how the argument bears on a specific first-order debate in metaphysics—the debate over whether there are composite objects. This debate is often thought to be a paradigm case of a metaphysical debate that is largely insulated from scientific considerations, and (...) is often disparaged or avoided by naturalistically-inclined metaphysicians as a result. My argument below shows that this attitude is a mistake. The way in which metaphysical debates can be informed by our best science is more complex and far-reaching than is often acknowledged in the literature. (shrink)

Mereological nihilism says that there do not exist (in the fundamental sense) any objects with proper parts. A reason to accept it is that we can thereby eliminate 'part' from fundamental ideology. Many purported reasons to reject it - based on common sense, perception, and the possibility of gunk, for example - are weak. A more powerful reason is that composite objects seem needed for spacetime physics; but sets suffice instead.

Our beliefs utilize various sources: perception, memory, induction, etc. We trust these sources to provide reliable information about the world around us. My dissertation investigates how this trust could be justified. Chapter one introduces background material. I argue that justification rather than knowledge is of primary epistemological importance, discuss the internalism/externalism debate, and introduce an evidentialist thesis that provides a starting point/framework for epistemological theorizing. Chapter two introduces a puzzle concerning justification. Can a belief source provide justification absent prior justification (...) for believing it's reliable? Any answer appears to either make justifying the reliability of a source intellectually unsatisfying or all together impossible. Chapter three considers and rejects a plethora of proposed solutions to our puzzle. Investigating these solutions illustrates the need to further investigate evidence, evidence possession, and evidential support. Chapter four discusses the metaphysics of evidence. I argue that evidence always consists of a set of facts and that fact-proposition pairs stand in confirmation relations isomorphic to those holding between pairs of propositions. Chapter five argues that justification requires what I call actually connected possession of supporting evidence: a subject must be aware of supporting evidence and of the support relation itself. Chapter six argues that the relation constitutive of a set of facts being justificatory evidence is a sui generis and irreducible relation that is knowable a priori. Chapter seven begins by showing how Richard Fumerton's acquaintance theory meets the constraints on a theory of justification laid down in previous chapters. I modify the theory so as to: make room for fallible foundational justification, and allow inferential justification absent higher-order beliefs about evidential connections. Chapter eight applies the developed theory of justification to our initial puzzle. I show how my modified acquaintance theory is in a unique position to vindicate the idea that necessarily a source provides a person with justification only if she is aware of evidence for the reliability of that source. However, this awareness of evidence for a source's reliability falls short of a justified belief and thereby avoids impalement from our dilemma's skeptical horn. (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)

This paper explores a few of the ways that the Zhuang-Zi can inform contemporary analytic epistemology. I begin, in section 1, by briefly outlining and summarizing the case for my fictionalist interpretation of the text. In section 2, I discuss how the Zhuang-Zi can be brought into productive dialogue with the question of how we should respond to skeptical arguments. Specifically, I argue that the Zhuang-Zi can be reasonably interpreted as exemplifying an approach that is different from dominant contemporary responses (...) to skeptical arguments in three ways: it is fictionalist; it motivates a skeptical perspective rather than a claim; and it accomplishes its aims in an atypical, but nonetheless contextually appropriate, way. However, the Zhuang-Zi is relevant to contemporary debates about skeptical arguments because it can be used: to respond to the same sorts of skeptical arguments that occupy contemporary commentators; to address a number of questions that arise in connection with such arguments; and to suggest important new questions for epistemologists to pursue. (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 aim of this dissertation is to provide a critique of the idea that skepticism was the driving force in the development of early modern thought. Historian of philosophy Richard Popkin introduced this thesis in the 1950s and elaborated on it over the next five decades, and recent scholarship shows that it has become an increasingly accepted interpretation. I begin with a study of the relevant historical antecedents—the ancient skeptical traditions of which early modern thinkers were aware—Pyrrhonism and Academicism. Then (...) I discuss the influence of skepticism on three pre-Cartesians: Francisco Sanches, Michel de Montaigne, and Pierre Charron. Basing my arguments on an informed understanding of both ancient Greek skepticism and some of the writings of these philosophers, I contend that it is inaccurate to predominantly characterize Sanches, Montaigne, and Charron as skeptics. To support his thesis about the singular influence of skepticism on early modern thought, Popkin says that René Descartes’ metaphysical philosophy was formed as a response to a skeptical threat and that Descartes ultimately conceded to the force of skepticism. He also argues that David Hume was a Pyrrhonist par excellence. I disagree with Popkin’s claims. I argue that Descartes was not as deeply affected by skepticism as Popkin suggests and that it is inaccurate to characterize Hume as a Pyrrhonist. By offering this critique, I hope to make clear to the readers two things: first, that Popkin’s thesis, though it is both enticing and generally accepted by many scholars, is questionable with regard to its plausibility; second, that the arguments I present in this dissertation reveal that further research into the role of skepticism in early modern philosophy is in order. (shrink)

The subject of this paper is the epistemology of identity: a general theory of knowledge, evidence and justification for the claim that one thing is identical to another. Although identity figures significantly in our epistemic lives, this is a topic that, to the best of my knowledge, has gone entirely unexplored. Initial attempts to integrate such an epistemology into existing theories of evidence---many of which are tailor-made for contingent propositions---are confounded by the necessity of identity. I defend a restricted form (...) of skepticism according to which the only knowable identity claims are trivial. (shrink)

Michael Williams has frequently considered and rejected approaches to "our knowledge of the external world" that see it as the best explanation for certain features of experience. This paper examines the salience of his position to approaches such as Mackie’s that do not deny the presentational directness of ordinary experience but do permit a gap between how things appear and how they are that allows for sceptical doubts. Williams’ main argument is that, to do justice to its place in a (...) foundationalist strategy, the external world as hypothesis must offer an explicandum that does not invoke concepts of objects but is rather purely experiential. He next claims that no coherent regularities are available at such a level so there is nothing to be explained. Coherence only comes with objects, not as something objects could explain. Confronting this with Mackie’s Lockean theory of perception, we find that Mackie decisively rejects the first claim about the nature of the explicandum, since he sees ordinary perception as involving intentional objects which are distinct from the persisting objects they present. He is also committed to rejecting Williams’ line on purely experiential regularities, though this plays a subordinate role in his general position. The crucial issue then becomes the tenability of Mackie’s intentional object analysis and the extent to which it might yet tilt the argument in favour of realism against a global sceptic. In formulating his own epistemological strategies Williams might appear to countenance a version of Mackie’s view divorced from foundationalism. But while Williams’ contextualism in its minimal version might do so, in practice it retains the lessons derived from his skirmishes with scepticism and thus disallows certain types of enquiry. I conclude by contrasting Mackie’s response to scepticism with that of Williams in his diagnostic vein. (shrink)

On the assumption that we may learn from our elders and betters, this paper approaches some fundamental questions in perceptual epistemology through a dispute between McDowell and Wright about external world scepticism.

Infallibilism is the claim that knowledge requires that one satisfies some infallibility condition. I spell out three distinct such conditions: epistemic, evidential and modal infallibility. Epistemic infallibility turns out to be simply a consequence of epistemic closure, and is not infallibilist in any relevant sense. Evidential infallibilism i s unwarranted but it is not an satisfactory characterization of the infallibilist intuition. Modal infallibility, by contrast, captures the core infallibilist intuition, and I argue that it is required to solve the Gettier (...) problem and account for lottery cases. Finally, I discuss whether modal infallibilism has sceptical consequences and argue that it is an open question whose answer depends on one’s account of alethic possibility. (shrink)

This paper focuses on a combination of the antiskeptical strategies offered by semantic externalism and the inference to the best explanation. I argue that the most difficult problems of the two strategies can be solved, if the strategies are combined: The strategy offered by semantic externalism is successful against standard skeptical brain-in-a-vat arguments. But the strategy is ineffective, if the skeptical argument is referring to the recent-envatment scenario. However, by focusing on the scenario of recent envatment the most difficult problems (...) of the antiskeptical strategy posed by the inference to the best explanation can be solved. The most difficult problems with this strategy are: Why is an explanation of our experience offered by the skeptical hypothesis more complex than our standard explanation? Why is the more complex explanation less likely to be true? By focussing on the recent envatment hypothesis both questions can be answered satisfactorily. Therefore, the combination of semantic externalism and the inference to the best explanation yields a powerful antiskeptical argument. (shrink)

If we add as an extra premise that the agent does know H, then it is possible for her to know E — H, we get the conclusion that the agent does not really know H. But even without that closure premise, or something like it, the conclusion seems quite dramatic. One possible response to the argument, floated by both Descartes and Hume, is to accept the conclusion and embrace scepticism. We cannot know anything that goes beyond our evidence, so (...) we do not know very much at all. This is a remarkably sceptical conclusion, so we should resist it if at all possible. A more modern response, associated with externalists like John McDowell and Timothy Williamson, is to accept the conclusion but deny it is as sceptical as it first appears. The Humean argument, even if it works, only shows that our evidence and our knowledge are more closely linked than we might have thought. Perhaps that’s true because we have a lot of evidence, not because we have very little knowledge. There’s something right about this response I think. We have more evidence than Descartes or Hume thought we had. But I think we still need the idea of ampliative knowledge. It stretches the concept of evidence to breaking point to suggest that all of our knowledge, including knowledge about the future, is part of our evidence. So the conclusion really is unacceptable. Or, at least, I think we should try to see what an epistemology that rejects the conclusion looks like. (shrink)

In “Why is There Anything at All?” Peter van Inwagen argues that even though it was never necessary that concrete beings existed, it was always maximally probable – just short of necessity – that they did . I argue that van Inwagen’s argument fails, albeit for an interesting reason which has remained so far unnoticed in the literature: there is a critical ten- sion between two of its premises, both essential to its soundness, concerning the nature of comprehensively specified possible (...) worlds. I summarize van Inwagen’s argument, develop this objection, and then describe more problems which invariably accrue when we try to ascribe probability values to possible worlds. (shrink)

Pritchard argues that epistemological disjunctivism seems plainly false at first sight, but if it were right, it would represent the “holy grail of epistemology” (1), a view that allows us “to have our cake and eat it too” (3). This prospect motivates Pritchard to develop and defend an account that prima facie might seem simply false. It is disputable whether ED really seems plainly false at first sight or whether this intuition is based on a particular philosophical tradition. However, in (...) this paper I will not discuss whether ED is actually true. Rather, I will investigate whether, if true, it has the advantages over rival accounts that Pritchard claims. (shrink)

In this dissertation I consider the problem of external world skepticism and attempts at providing an argument to the best explanation against it. In chapter one I consider several different ways of formulating the crucial skeptical argument, settling on an argument that centers on the question of whether we're justified in believing propositions about the external world. I then consider and reject several options for getting around this issue which I take to be inadequate. I finally conclude that the best (...) option available to us at the moment is to argue that the antiskeptical view is the best explanation of our ordinary experiences In chapter two I argue that, if we hope to ground what counts as defending antiskepticism in common sense, there is an argument against the possibility of ever knowing one has succeeded in defending antiskepticism. After showing that common sense is no place to look in setting a goal for our antiskeptical project, I present the view that what will be crucial to settling on our antiskeptical goal is coming to a successful analysis of the nature of physical objects. I suggest some minimal criteria that must be met by a view in order to be antiskeptical based on our intuitions about core skeptical cases, but acknowledge that a fully successful response to external world skepticism will require the antiskeptic to engage in some much more difficult analysis. In chapter three I consider various views of the nature of explanation and conclude, tentatively, that explanation as it interests the antiskeptic is fundamentally causal. In chapter four I consider and reject some of the core views on which best explanation facts are so fundamental that a project of attempting to vindicate probabilistically the virtues which make explanations epistemically good. In this chapter I show that views which analyze justification in terms of best explanation factors fail. In chapter five I attempt to vindicate the various explanatory virtues probabilistically. In doing so I attempt to express or translate the various explanatory virtues in terms of probabilities in order to show that having those virtues makes a view at least prima facie more probable. In chapters six and seven I explain and evaluate the various arguments to the best explanation against skepticism present in current philosophical literature. I attempt to show that extant arguments fail to appreciate the virtues possessed by classical skeptical scenarios. In chapter eight I briefly consider some options that may be open to the antiskeptic moving forward. All routes forward contain considerable obstacles, but there are some fruitful areas of research to pursue. (shrink)

The problem of philosophical skepticism relates to the difficulty involved in underwriting the claim that we know anything of spatio-temporal reality. It is often claimed, in fact, that proper philosophical scrutiny reveals quite the opposite from what common sense suggests. Knowledge of external reality is thought to be even quite obviously denied to us as a result of the alleged fact that we all fail to know that certain skeptical scenarios do not obtain. A skeptical scenario is one in which (...) we have neurological occurrences just like any normal situation in which we actually perceive spatio-temporal objects, but where we are deceived in some sense as a result of the manipulation of our brains from some outside source. In this work I attempt to address the problem of philosophical skepticism by claiming that most of us are able to come to know plenty about external reality, since we can come to realize that a certain philosophical theory of perception is correct. The theory I have in mind is what I call a non-cognitive theory of perception. According to this view, perceptual experience is defined by continuous, sensitive behavioral interaction with spatio-temporal objects of the appropriate size, shape, hardness, speed, etc. Knowing that this theory of perception is correct is equivalent to knowing that we know plenty about external reality. This is ultimately because by knowing that a non-cognitive theory of perception is true, we know that any skeptical scenario must fail to obtain. The structure of the work proceeds by first discussing the significance of the problem of philosophical skepticism in some detail. Chapter 1 lays out how the problem does indeed forcefully arise if it is conceded that we fail to know that the skeptical scenarios fail to obtain. Chapter 2 develops the sort of view of our epistemological situation that falls out of accepting without qualification that the problem exists. Chapter 3 examines and criticizes certain popular responses to the skeptical problem. The main goal of these first three preliminary chapters is to indicate that once it is admitted that we fail to know that the skeptical scenarios fail to obtain, the problem of philosophical skepticism forcefully presents itself. Chapter 4, however, attacks the idea that we fail to know that the skeptical scenarios fail to obtain. In this chapter I argue that this idea is wedded to the position that a certain theory of perception is correct. The theory in question is what I call a conjunctive theory of veridical experience. According to this view, normal experience of spatio-temporal objects occurs when a subject has a certain perceptual experience, and that experience also happens to match up with and/or be satisfied by what is really the case. Only when a theory of this sort is assumed, I argue, is the claim that we fail to know that the skeptical scenarios fail to obtain found to be obvious. In chapter 5 I argue that, in fact, a non-cognitive theory, rather than a conjunctive theory, is the correct view to maintain. In the final chapter 6 I develop the epistemological position that falls out of accepting a non-cognitive theory. (shrink)