Experimental philosophers are often puzzled as to why many armchair philosophers question the philosophical significance of their research. Armchair philosophers, in contrast, are often puzzled as to why experimental philosophers think their work sheds any light on traditional philosophical problems. I argue there is truth on both sides.

Dretske’s theory of self-knowledge is interesting but peculiar and can seem implausible. He denies that we can know by introspection that we have thoughts, feelings, and experiences. But he allows that we can know by introspection what we think, feel, and experience. We consider two puzzles. The first puzzle, PUZZLE 1, is interpretive. Is there a way of understanding Dretske’s theory on which the knowledge affirmed by its positive side is different than the knowledge denied by its negative side? The (...) second puzzle, PUZZLE 2, is substantive. Each of the following theses has some prima facie plausibility: there is introspective knowledge of thoughts, knowledge requires evidence, and there are no experiences of thoughts. It is unclear, though, that these claims form a consistent set. These puzzles are not unrelated. Dretske’s theory of self-knowledge is a potential solution to PUZZLE 2 in that Dretske’s theory is meant to show how,, and can all be true. We provide a solution to PUZZLE 1 by appeal to Dretske’s early work in the philosophy of language on contrastive focus. We then distinguish between “Closure” and “Transmissibility”, and raise and answer a worry to the effect that Dretske’s theory of self-knowledge runs counter to Transmissibility. These results help to secure Dretske’s theory as a viable solution to PUZZLE 2. (shrink)

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

The 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)

I propose an account of desire that reconciles two apparently conflicting intuitions about practical agency. I do so by exploring a certain intuitive datum. The intuitive datum is that often when an agent desires P she will seem to immediately and conclusively know that there is a reason to bring P about. Desire-based theories of reasons seem uniquely placed to explain this intuitive datum. On this view, desires are the source of an agent’s practical reasons. A desire for P grounds (...) conclusive knowledge of a reason to bring P about because that desire makes it true that there is a reason to do so. However, this implies that a basic desire for P can never be in error about there being at least some reason to bring P about. We have the conflicting intuition that basic desires sometimes rationally count for nothing. The guise of the good explains this intuition about the fallibility of desires. On this view, a desire for P represents P as good in some respect. Desires and reasons are independent, so a desire might misrepresent one’s reasons. But this independence is usually taken to rule out that desires ever provide conclusive knowledge of reasons. Capturing the intuition about conclusive knowledge rules out capturing the intuition about fallibility, and vice versa. I propose an epistemological disjunctivist version of the guise of the good that reconciles fallibility with the possibility of conclusive knowledge. (shrink)

Suppose one has a visual experience as of having hands, and then reasons as follows: I have hands, If I have hands an external world exists; An external world exists. Suppose one’s visual experience gives one defeasible perceptual warrant, or justification, to believe – that is, one’s experience makes it epistemically appropriate to believe . And suppose one comes to believe on the basis of this visual experience. The conditional premise is knowable a priori. And can be established by modus (...) ponens inference. If one reasons thus, say one’s engaged in -reasoning. What, if anything, is wrong with -reasoning? I consider two prominent responses to this question – the dogmatists’ and Crispin Wright’s. Each finds fault in -reasoning, but on different grounds. I argue Wright’s response faces a problem which is standardly only taken to be faced by dogmatists. (shrink)

Stewart Cohen considers a case where his son wants a red table for his room. Cohen and his son go to the furniture store. Cohen’s son is concerned that the table his father is considering purchasing, which appears red, may in fact be white with red lights shining on it. Cohen responds with the following reasoning: The table looks red. The table is red. If the table is red, then it is not white with red lights shining on it. The (...) table is not white with red lights shining on it. If one reasons thus, say one’s engaged in -reasoning. Cohen finds such a response unsatisfactory. It is not a way of coming to know —it is too easy. And structurally similar reasoning delivers the falsity of sceptical hypotheses concerning the external world, testimony, other minds etc. So the unsatisfactoriness threatens to generalise. I consider Martin Davies ’s attempt to diagnose this unsatisfactoriness and find it incomplete. I then attempt to remedy the incompleteness in Davies ’s attempt. (shrink)

One common objection to Dretske’s Information Theoretic Account of Knowledge (ITAK) is that it violates closure. I show that it does not, and that extant arguments attempting to establish that it does rely instead on the KK thesis. That thesis does fail for ITAK. I show moreover that an interesting consequence of ITAK obeying the closure principle after all is that on this view if skepticism is false, we can have a great deal of empirical knowledge, but it is in (...) principle impossible to know that skepticism is false. In short, a proper understanding of how ITAK closes off the KK thesis shows that we can 1) take seriously the skeptic, we can 2) respond to her appropriately that we do have knowledge and we can 3) keep closure. (shrink)

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

If knowledge requires safety, then one might think that when the epistemic source of knowledge is testimony, that testimony must itself be safe. Otherwise, will not the lack of safety transfer from testimony to hearer, such that hearer will lack knowledge? Resisting this natural line of reasoning, Goldberg (2005; 2007) argues that testimonial knowledge through unsafe testimony is possible on the basis of two cases. Lackey (2008) and Pelling (2013) criticize Goldberg’s examples. But Pelling goes on to provide his own (...) example that attempts to show that Goldberg’s thesis is true: one can gain safe testimonial belief from unsafe testimony. If any of these counterexamples were correct, they would undermine the main reason to think that knowledge based on unsafe testimony is impossible. My aim in this paper is to critically assess these arguments, and to consider the possibility of knowledge through unsafe testimony. Drawing a general moral from the analysis of these cases, I shall contend that it is impossible to acquire safe belief solely on the basis of unsafe testimony. If so, then testimonial knowledge based solely on unsafe testimony is impossible. (shrink)

Neste ensaio, pretendemos (1) sugerir algumas vantagens da apresentação do ceticismo na forma de um argumento cético geral, (2) discutir o princípio de fechamento utilizado neste argumento, (3) mostrar que o confiablismo externalista é incapaz de explicar as implicações deste argumento geral e (4) defender uma posição internalista cancelabilista como a mais adequadamente munida de ferramentas para avaliação dos desafios céticos.

Suppose Ted is in an ordinary house in good viewing conditions and believes red, his table is red, entirely because he sees his table and its color; he also believes not-white, it is false that his table is white and illuminated by a red light, because not-white is entailed by red. The following three claims about this table case clash, but each seems plausible: 1. Ted’s epistemic position is strong enough for him to know red. 2. Ted cannot know not-white (...) on the basis of red. 3. The epistemic closure principle, suitably restricted, is true. Stewart Cohen has called this three-way clash of intuitions the problem of easy knowledge. If we wish to resolve the clash without accepting skepticism, we seem to have two options. According to the hard argument, the best response is to reject 3. The easy argument rejects 2. But there may be a third alternative, the reverse argument, which rejects 1 without ceding a substantial amount of ground to the skeptic. In this essay I criticize recent versions of the reverse argument and the hard argument, thereby lending support to the easy argument. (shrink)

In early essays and in more recent work, Fred Dretske argues against the closure of perception, perceptual knowledge, and knowledge itself. In this essay I review his case and suggest that, in a useful sense, perception is closed, and that, while perceptual knowledge is not closed under entailment, perceptually based knowledge is closed, and so is knowledge itself. On my approach, which emphasizes the safe indication account of knowledge, we can both perceive, and know, that sceptical scenarios (such as being (...) a brain in a vat) do not hold. (shrink)

Recently, Jonathan Schaffer has defended a contrastivist analysis of knowledge. By appealing to his account, he has attempted to steer a path between skepticism and Moore-style antiskepticism: much like sensitivity theorists and contextualists, he offers significant concessions to, but ultimately rejects, both. In this essay I suggest that in fact Schaffer ends up succumbing to skepticism.

In this paper, I examine Crispin Wright’s most recent attempt to introduce a diagnostic tool for predicting failures of warrant transmission, the so-called ‘Revised Template’. I show that the Revised Template does not, in fact, generate the predictions about warrant transmission failure that Wright thinks it does. I argue that the failure lies, in large part, with the definition of the technical notion ‘presupposition’ which the Revised Template deploys. Through a consideration of Wright’s own ‘general motivation’ for the Revised Template, (...) I extract an alternative characterization of ‘presupposition’ and use this to fuel a diagnostic tool for predicting failures of warrant transmission which, I believe, is both more faithful to Wright’s own general motivating remarks and more successful in predicting failures of warrant transmission than the Revised Template. (shrink)

May argues that moral skepticism is less plausible than perceptual skepticism if it’s formulated using epistemic closure. In this paper, I argue we should be skeptical of the implausibility thesis. Moral skepticism can be formulated using closure if we combine moral nihilism with a properly formulated evolutionary scenario. Further, I argue that pace May, the phenomenon of ‘imaginative resistance’ isn’t an issue for the moral skeptic; she has an evolutionary explanation of the phenomenon. Thus, we should be skeptical of the (...) implausibility thesis. (shrink)

There is a controversy, within social epistemology, over how to handle disagreement among epistemic peers. Call this the problem of peer disagreement. There is a solution, i.e. the equal-weight view, which says that disagreement among epistemic peers is a reason for each peer to lower the credence they place in their respective positions. However, this solution is susceptible to a serious challenge. Call it the merely modal peers challenge. Throughout parts of modal space, which resemble the actual world almost completely, (...) there are hordes of epistemic peers, who disagree with almost any arbitrarily chosen belief had by residents of the actual world. Further, the mere modality of these peers is not itself an epistemic difference-maker. Thus, on the equal-weight view, we should significantly lower the credence we place in most of our beliefs. Surely, this is seriously mistaken. Thus, there are serious considerations that cut against the equal-weight view. (shrink)

Radical experimentalists argue that we should give up using intuitions as evidence in philosophy. In this paper, I first argue that the studies presented by the radical experimentalists in fact suggest that some intuitions are reliable. I next consider and reject a different way of handling the radical experimentalists' challenge, what I call the Argument from Robust Intuitions. I then propose a way of understanding why some intuitions can be unreliable and how intuitions can conflict, and I argue that on (...) this understanding, both moderate experimentalism and the standard philosophical practice of using intuitions as evidence can help resolve these conflicts. (shrink)

All standard epistemic logics legitimate something akin to the principle of closure, according to which knowledge is closed under competent deductive inference. And yet the principle of closure, particularly in its multiple premise guise, has a somewhat ambivalent status within epistemology. One might think that serious concerns about closure point us away from epistemic logic altogether—away from the very idea that the knowledge relation could be fruitfully treated as a kind of modal operator. This, however, need not be so. The (...) abandonment of closure may yet leave in place plenty of formal structure amenable to systematic logical treatment. In this paper we describe a family of weak epistemic logics in which closure fails, and describe two alternative semantic frameworks in which these logics can be modelled. One of these—which we term plurality semantics—is relatively unfamiliar. We explore under what conditions plurality frames validate certain much-discussed principles of epistemic logic. It turns out that plurality frames can be interpreted in a very natural way in light of one motivation for rejecting closure, adding to the significance of our technical work. The second framework that we employ—neighbourhood semantics—is much better known. But we show that it too can be interpreted in a way that comports with a certain motivation for rejecting closure. (shrink)

The skeptical puzzle consists of three independently plausible yet jointly inconsistent claims: (A) S knows a certain ordinary proposition op; (B) S does not know the denial of a certain skeptical hypothesis sh; and (C) S knows that op only if S knows that not- sh. The variantist solution (to the skeptical puzzle) claims that (A) and not-(B) are true in the ordinary context, but false in the skeptical one. Epistemic contextualism has offered a standards-variantist solution, which is the most (...) prominent variantist solution on the market. In this paper, I argue that the standards-variantist solution in general (and the contextualist solution in particular) is epistemically uninteresting. Proponents of the variantist solution should opt for the position-variantist solution instead. I will discuss some important implications of my findings. (shrink)

The notion of relevance plays a role in many accounts of knowledge and knowledge ascription. Although use of the notion is well-motivated, theorists struggle to codify relevance. A reasonable person standard of relevance addresses this codification problem, and provides an objective and flexible standard of relevance; however, treating relevance as reasonableness seems to allow practical factors to determine whether one has knowledge or not—so-called “pragmatic encroachment.” I argue that a fuller understanding of reasonableness and of the role of practical factors (...) in the acquisition of knowledge lets us avoid pragmatic encroachment. (shrink)

It is tempting to think that multi premise closure creates a special class of paradoxes having to do with the accumulation of risks, and that these paradoxes could be escaped by rejecting the principle, while still retaining single premise closure. I argue that single premise deduction is also susceptible to risks. I show that what I take to be the strongest argument for rejecting multi premise closure is also an argument for rejecting single premise closure. Because of the symmetry between (...) the principles, they come as a package: either both will have to be rejected or both will have to be revised. (shrink)

Certain well-known intuitions suggest that, contrary to traditional thinking in epistemology, knowledge judgements are shifty—i.e., that judgements about whether somebody knows something can shift in stringency with context. Some take these intuitions to show that knowledge judgements are shifty. Jennifer Nagel and Mikkel Gerken have argued, however, that closer attention to the psychological processes which underlie knowledge judgements shows how traditional non-shifty thinking can be preserved. They each defend moderate classical invariantism—the view that the epistemic standard for knowing is always (...) moderate—by drawing on recent work in cognitive psychology. This paper argues that neither attempt succeeds. (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)

It is epistemological orthodoxy that the object of propositional knowledge is the truth of propositions. This traditional view is based on what I call the ‘KT-schema’, viz, ‘S knows that p, iff, S knows that “p” is true’. The purpose of this paper is to reject the KT-schema. By showing the paradoxical upshot of the KT-schema and providing counterexamples to the KT-schema, this paper argues that ‘knowing that p’ is more than ‘knowing that “p” is true’. Consequently, we shall rethink (...) the object problem of propositional knowledge – if knowing that p is not merely knowing that ‘p’ is true, then what is indeed the object of propositional knowledge? I will also attempt to solve this problem by proposing a complementary answer: knowing that p requires at least knowing the truth of p, plus, understanding the content of p. (shrink)

El objetivo central de este trabajo consiste en articular la noción de cooperación epistémica con la de fiabilidad, ofreciendo una alternativa al intelectualismo. La tesis principal radica en que la fiabilidad de los procesos epistémicos se conforman a partir de que los sujetos cooperan unos con otros en la atribución de conocimiento. De esta manera la cooperación epistémica se vincula con varias posiciones teóricas: con el contextualismo, al constituir un contexto flexible o exigente para la aceptación de proposiciones; con una (...) respuesta al escepticismo, pues el escéptico permanece aislado del contexto de enunciación, con el inductivismo y la circularidad, pues mediante la cooperación epistémica se determina en qué contextos el inductivismo y la circularidad son argumentos legítimos. (shrink)

According to contextualist accounts, the truth value of a given knowledge ascription may vary with features of the ascriber's context. As a result, the following may be true: "X doesn't know that P but Y says something true in asserting 'X knows that P'". The contextualist must defend his theory in the light of this unpleasant but inevitable consequence. The best way of doing this is to construe the context sensitivity of knowledge ascriptions not as deriving from an alleged indexicality (...) of the word "know" nor from its vagueness or ambiguity, but rather from a distinct semantic feature of the word "know", namely its unspecificity. (shrink)

The central motivation behind the scientific realism debate is explaining the impressive success of scientific theories. The debate has been dominated by two rival types of explanations: the first relies on some sort of static, referentially transparent relationship between the theory and the unobservable world, such as truthlikeness, representation, or structural similarity; the second relies on no robust relationship between the theory and unobservable reality at all, and instead draws on predictive similarity and the stringent methodology of science to explain (...) success. I argue that this is a false dichotomy, at least insofar as dynamical theories are concerned. The best explanation of the success of dynamical theories, I argue, must appeal to a robust but referentially opaque theory–world relation. The dynamical notion of ‘tracking’ fulfills this promise. I formulate a modified no miracles argument that is liberated from the false dichotomy and show how tracking responds to the modified argument. (shrink)

We describe the three place relation of contrastive knowledge, which holds between a person, a target proposition, and a contrasting proposition. The person knows that p rather than that q. We argue for three claims about this relation. (a) Many common sense and philosophical ascriptions of knowledge can be understood in terms of it. (b) Its application is subject to fewer complications than non-contrastive knowledge is. (c) It applies over a wide range of human and nonhuman cases.

How engineers know, and act on that knowledge, has a profound impact on society. Consequently, the analysis of engineering knowledge is one of the central challenges for the philosophy of engineering. In this article, we present a thematic multidisciplinary conceptual survey of engineering epistemology and identify key areas of research that are still to be comprehensively investigated. Themes are organized based on a survey of engineering epistemology including research from history, sociology, philosophy, design theory, and engineering itself. Five major interrelated (...) themes are identified: the relationship between scientific and engineering knowledge, engineering knowledge as a distinct field of study, the social epistemology of engineering, the relationship between engineering knowledge and its products, and the cognitive aspects of engineering knowledge. We discuss areas of potential future research that are underdeveloped or “undone.”. (shrink)

Process reliabilists hold that in order for a belief to be justified, it must result from a reliable cognitive process. They also hold that a belief can be basically justified: justified in this manner without having any justification to believe that belief is reliably produced. Fumerton (1995), Vogel (2000), and Cohen (2002) have objected that such basic justification leads to implausible easy justification by means of either epistemic closure principles or so-called track record arguments. I argue that once we carefully (...) distinguish closure principles from transmission principles, and epistemic consequences from epistemic preconditions, neither version of this objection succeeds. (shrink)

Reliabilists accept the possibility of basic knowledge—knowledge that p in virtue of the reliability of some belief-producing process r without antecedent knowledge that r is reliable. Cohen (Philos Phenomenol Res 65:309–329, 2002 , Philos Phenomenol Res 70:417–430, 2005 ) and Vogel (J Philos 97:602–623, 2000 , J Philos 105:518–539, 2008 ) have argued that one can bootstrap knowledge that r is reliable from basic knowledge. This paper provides a diagnosis of epistemic bootstrapping, and then shows that recent attempts at embracing (...) bootstrapped knowledge are found wanting. Instead it is argued that such arguments are afflicted by a novel kind of generalized epistemic circularity. The ensuing view is defended against various objections, and an explanation of the source of that circularity is offered. (shrink)

It has sometimes been suggested that people represent the structure of action in terms of an action tree. A question now arises about the relationship between this action tree representation and people’s moral judgments. A natural hypothesis would be that people first construct a representation of the action tree and then go on to use this representation in making moral judgments. The present paper argues for a more complex view. Specifically, the paper reports a series of experimental studies that appear (...) to show that people’s moral judgments can actually impact their representations of the action tree itself. (shrink)

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

Craig casts doubt upon the project of trying to give the traditional sort of necessary and sufficient conditions for A knows that p. He interprets the inadequacy of existing analyses of knowledge as evidence that our concept of knowledge is complex and diffuse, and concludes that we should aim to understand it by thinking about the rôle the concept plays in our lives, rather than by trying to find necessary and sufficient conditions for the truth of knowledge ascriptions.There is surely (...) something right about Craig's view: we are unlikely to succeed in any attempt to analyse away the intricacies in our concept of knowledge. We cannot realistically hope to uncover a set of necessary and sufficient conditions for A knows that p which are in all cases either clearly satisfied or clearly not satisfied. Nor, I suspect, is it possible to offer necessary and sufficient conditions for knowledge which are widely accepted as being more securely understood than knowledge itself. (shrink)

– We offer a new motivation for imprecise probabilities. We argue that there are propositions to which precise probability cannot be assigned, but to which imprecise probability can be assigned. In such cases the alternative to imprecise probability is not precise probability, but no probability at all. And an imprecise probability is substantially better than no probability at all. Our argument is based on the mathematical phenomenon of non-measurable sets. Non-measurable propositions cannot receive precise probabilities, but there is a natural (...) way for them to receive imprecise probabilities. The mathematics of non-measurable sets is arcane, but its epistemological import is far-reaching; even apparently mundane propositions are liable to be affected by non-measurability. The phenomenon of non-measurability dramatically reshapes the dialectic between critics and proponents of imprecise credence. Non-measurability offers natural rejoinders to prominent critics of imprecise credence. Non-measurability even reverses some of the critics’ arguments—by the very lights that have been used to argue against imprecise credences, imprecise credences are better than precise credences. (shrink)

This paper introduces and defends the paradigm response to external world skepticism. To understand it, consider an analogy. One of the hallmarks of being a bird is an ability to fly. A penguin lacks this hallmark and thus fails to be a paradigm bird. Likewise, there are various hallmarks of knowledge. Some of your external world beliefs lack some of these hallmarks, and thus fail to be paradigm cases of knowledge. Just as the inability of penguins to fly doesn’t prevent (...) them from being birds, likewise the lack of these hallmarks doesn’t prevent your beliefs from being knowledge. It just prevents them from being paradigm cases thereof. (shrink)

Tyler Burge says that first-person authority can be reconciled with anti-individualism about the intentional by denying part of the "Cartesian conception" of authority, which claims that I am actually authoritative about my intentional attitudes in counterfactual situations. This clause, he says, wrongly conflates the evaluation-conditions for sceptical doubts about the "external" world with the conditions for classifying intentional attitudes in counterfactual situations. This paper argues that the kind of possibility needed to understand external-world scepticism justifies the conflation and that Burge (...) can reject the Cartesian conception only if he rejects either metaphysical realism or anti-individualism. (shrink)

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

In spite of the intuitiveness of epistemic closure, there has been a stubborn stalemate regarding whether it is true, largely because some of the “Moorean” things we seem to know easily seem clearly to entail “heavyweight” philosophical things that we apparently cannot know easily—or perhaps even at all. In this paper, I will show that two widely accepted facts about what we do and don’t know—facts with which any minimally acceptable understanding of knowledge must comport—are jointly inconsistent with the truth (...) of CLR. The proof works by supposing the truth of “Categorialism,” a thesis about the relation between basic categories and common nouns and predicates, which is itself a heavyweight claim that cannot be easily known to be either true or false. (shrink)

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

According to the safety condition, a subject knows that p only if she would believe that p only if p was true. The safety condition has been a very popular necessary condition for knowledge of late. However, it is well documented that the safety condition is trivially satisfied in cases where the subject believes in a necessary truth. This is for the simple reason that a necessary truth is true in all possible worlds, and therefore it is true in all (...) possible worlds where it is believed. But clearly, all beliefs concerning necessary truths do not amount to knowledge. The safety theorists have attempted to deal with the problem caused by necessary truths by restricting the safety condition to purely contingent truths and by globalizing the safety condition to a set of propositions. Both of these solutions are problematic. The principal aim of this paper is to develop a version of the safety condition that is able to deal with cases featuring necessary truths. (shrink)

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

Taking his conceptual cue from Ernest Sosa, John Turri has offered a putative conceptual solution to the Gettier problem: Knowledge is cognitively adept belief, and no Gettiered belief is cognitively adept. At the core of such adeptness is a relation of manifestation. Yet to require that relation within knowing is to reach for what amounts to an infallibilist conception of knowledge. And this clashes with the spirit behind the fallibilism articulated by Gettier when stating his challenge. So, Turri’s form of (...) response is irrelevant to that challenge, which was intended to pose a conceptual problem within fallibilist conceptions of knowledge. (And that failure on Turri’s part needs to be highlighted to remind epistemologists of the need to assess Gettier cases by a fallibilist standard. Although that need was described earlier by Robert Almeder, apparently his advice is being overlooked. This paper develops it anew, in a more general form.). (shrink)

This paper undermines a paradigmatic form of sceptical reasoning. It does this by describing, and then dialectically dissolving, the sceptical-independence presumption, upon which that form of sceptical reasoning relies.