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

Linda Zagzebski’s work in analytic epistemology is largely responsible for several sea changes in the field in the late twentieth century. Coming from one of th.

In this paper I assess the two central ingredients of Laurence BonJour’s position on empirical knowledge that have survived the transition from his earlier coherentist views to his current endorsement of the doctrine of the given: his construal of the problem of the epistemic regress and his rejection of an internalist solution to the problem. The bulk of the paper is devoted to a critical assessment of BonJour’s arguments against externalism. I argue that they fail to put real pressure on (...) externalism, as they rely on a highly questionable conception of epistemic rationality and responsibility. Then, more briefly, I take issue with BonJour’s endorsement of the irrelevance thesis—the claim that even if externalism were true it would not offer a satisfactory solution to the epistemic regress problem. I contend that he is not entitled to subscribe this thesis unless he is prepared to abandon his construal of the problem. (shrink)

This paper explains how the notion of justification transmission can be used to ground a notion of knowledge transmission. It then explains how transmission theories can characterise schoolteacher cases, which have prominently been presented as counterexamples to transmission theories.

Hume’s famous argument against the credibility of testimony about miracles invokes two premises: 1) The reliability of the witness (the extent to which he is informed and truthful) must be compared with the intrinsic probability of the miracle. 2) The initial probability of a miracle is always small enough to outweigh the improbability that the testimony is false (even when the witness is assumed to be reliable). I defend the first premise of the argument, showing that Hume’s argument can be (...) applied to purported observations of miracles, as well. I then show that Hume failed to provide an adequate support for his second premise. A more cogent defence can be provided for a weaker premise. The resultant argument has, consequently, a less sweeping conclusion than Hume’s. (shrink)

Using empirical evidence to attack intuitions can be epistemically dangerous, because various of the complaints that one might raise against them (e.g., that they are fallible; that we possess no non-circular defense of their reliability) can be raised just as easily against perception itself. But the opponents of intuition wish to challenge intuitions without at the same time challenging the rest of our epistemic apparatus. How might this be done? Let us use the term “hopefulness” to refer to the extent (...) to which we possess a good capacity for the detection and correction of the errors of any fallible source of evidence. I argue that we should not trust putative sources of evidence that are substantially lacking in hopefulness (even if they are basically reliable), and that we are indeed already operating under such a norm in our ordinary and scientific practices. I argue further that the philosophical practice of the appeal to intuitions is, in these terms, badly hopeless... (shrink)

It has recently been argued that the following Rule should be part of any characterization of science: Claims concerning specific disputed facts should be endorsed only if they are sufficiently supported by the application of validated methods of research or discovery, and moreover that acceptance of this Rule should lead one to reject religious belief. This paper argues, first, that the Rule, as stated, should not be accepted as it suffers from a number of problems. And second, that even if (...) the Rule were to be acceptable, it should not lead one to reject religious belief. (shrink)

This paper argues that reading is a source of knowledge. Epistemologists have virtually ignored reading as a source of knowledge. This paper argues, first, that reading is not to be equated with attending to testimony, and second that it cannot be reduced to perception. Next an analysis of reading is offered and the source of knowledge that reading is further delineated. Finally it is argued that the source that reading is, can be both transmissive and generative, is non-basic, once was (...) a non-essential but has become essential for many people, and can be unique. (shrink)

RÉSUMÉMalgré son usage très répandu, l'inférence à la meilleure explication a souvent été considérée avec suspicion par des théoriciens d'allégeances diverses. On lui a reproché à maintes reprises defaire reposer son recours à la simplicité et ses autres vertus explicatives sur des présuppositions métaphysiques douteuses. J'aborde ces questions, dans le présent article, dans le contexte d'une discussion large de l'usage de l'IME pour fonder notre croyance au monde extérieur. Distinguant entre la légitimité et l'efficacité de l'IME, je soutiendrai qu'elle constitue (...) bien une forme légitime d'inférence, mais que son efficacité dépend de la fonction de la théorie de la connaissance qui la supporte. (shrink)

RÉSUMÉMalgré son usage très répandu, l'inférence à la meilleure explication a souvent été considérée avec suspicion par des théoriciens d'allégeances diverses. On lui a reproché à maintes reprises defaire reposer son recours à la simplicité et ses autres vertus explicatives sur des présuppositions métaphysiques douteuses. J'aborde ces questions, dans le présent article, dans le contexte d'une discussion large de l'usage de l'IME pour fonder notre croyance au monde extérieur. Distinguant entre la légitimité et l'efficacité de l'IME, je soutiendrai qu'elle constitue (...) bien une forme légitime d'inférence, mais que son efficacité dépend de la fonction de la théorie de la connaissance qui la supporte. (shrink)

Andy believes that p because his tarot cards indicate that p. Betty believes that ∼p because her crystal ball reveals that ∼p. If Andy and Betty know that they disagree, and disagree because they engage in different practices, is Andy's belief that p rational? The answer depends in part on whether Andy has good reasons to think that reading tarot cards is reliable about the topic while reading crystal balls is not. If a person has good reasons to believe that (...) practice P1 is reliable while a competing practice P2 is not, then it is not irrational to form beliefs by engaging in P1. What if a person does not have good reasons to think that one practice is reliable about a topic while competing practices are not, though? In such cases, would Andy's awareness of the existence of competing practices, on its own, be enough to render his belief that p irrational? (shrink)

A modest transcendental argument is one that sets out merely to establish how things need to appear to us or how we need to believe them to be, rather than how things are. Stroud's claim to have established that all transcendental arguments must be modest in this way is criticised and rejected. However, a different case for why we should abandon ambitious transcendental arguments is presented: namely, that when it comes to establishing claims about how things are, there is no (...) reason to prefer transcendental arguments to arguments that rely on the evidence of the senses, making the former redundant in a way that modest transcendental arguments, which have a different kind of sceptical target, are not. (shrink)

Is it possible to argue that one’s memory is reliable without using one’s memory? I argue that it is not. Since it is not, it is impossible to defend the reliability of one’s memory without employing reasoning that is epistemically circular. Hence, if epistemic circularity is vicious, it is impossible to succeed in producing a cogent argument for the reliability of one’s memory. The same applies to any other one of one’s cognitive faculties. I further argue that, if epistemic circularity (...) is vicious, it is impossible to produce a cogent argument for the reliability of anything. For example, if epistemic circularity were vicious, a cogent argument for the reliability of one’s car would not be possible. The seeming viciousness of epistemic circularity even threatens, I propose, the possibility of justification and knowledge. Much, therefore, hangs one the question of whether epistemic circularity is indeed bad. I argue that epistemic circularity, or bootstrapping, need not be bad. When we use a crystal ball—a source perspicuously guilty of unreliability—to confirm its own reliability, bootstrapping is foolish. When we attribute reliability to a witness solely because the witness says he is reliable, bootstrapping is dogmatic. Foolish and dogmatic bootstrapping are bad. However, when a witness provides a rich body of testimony, using that testimony to gauge the witness’s reliability need not be a vicious form of circularity. When done critically, I argue, such reasoning exemplifies a form of bootstrapping that is benign. (shrink)

Defeaters can prevent a perceptual belief from being justified. For example, when you know that red light is shining at the table before you, you would typically not be justified in believing that the table is red. However, can defeaters also destroy a perceptual experience as a source of justification? If the answer is ‘no’, the red light defeater blocks doxastic justification without destroying propositional justification. You have some-things-considered, but not all-things-considered, justification for believing that the table is red. If (...) the answer is ‘yes’, the red light defeater blocks doxastic justification by destroying propositional justification. You have neither all-things-considered nor some-things-considered justification for believing that the table is red. According to dogmatism, the justificational force of perceptual experiences is indestructible. According to conservatism about sense experience, a perceptual experience ceases to have justificational force if there is evidence against its reliability. Finally, according to meta-evidentialism, a perceptual experience is blocked from being a source of justification is there is no evidence of its reliability. I argue that, of these three theories, meta-evidentialism is the most plausible. (shrink)

The idea that intuition plays a basic role in moral knowledge and moral philosophy probably began in the eighteenth century. British philosophers such as Anthony Shaftsbury, Francis Hutcheson, Thomas Reid, and later David Hume talk about a “moral sense” that they place in John Locke’s theory of knowledge in terms of Lockean reflexive perceptions, while Richard Price seeks a faculty by which we obtain our ideas of right and wrong. In the twentieth century intuitionism in moral philosophy was revived by (...) the works of G. E. Moore, H. A. Prichard, and W. D. Ross. These philosophers reject Kantian deontological ethics and utilitarianism insisting that intuition is the only source of moral knowledge. Recently, there is a renewed interest in intuition by philosophers doing meta-philosophy by reflecting on what philosophers do, and why they disagree. In this essay we plan to take some of this recent literature on intuition and apply it to moral philosophy. We will proceed by defining a conception of intuition, answering some skeptical challenges, delimiting its target, and arguing that intuition is often a source of moral knowledge. (shrink)

In this paper, I argue that the success of evolutionary debunking arguments hinges on what theory of epistemic justification one endorses. More specifically, I argue that what it takes to satisfactorily respond to evolutionary debunking arguments depends on what view of epistemic justification one is operating under and that a thorough analysis of any line of response to evolutionary debunking arguments must take into account whether there is a specific view of justification motivating the response or looming in the background. (...) In particular, I argue that pace Andrew del Rio’s claim in the article “Why Undermining Evolutionary Debunkers is Not Enough,” merely undermining the empirical claim can in fact be a successful line of response to debunkers if one endorses a particular version of doxastic conservatism. I also argue that examining how satisfying a response to an evolutionary debunking argument seems to us and considering what theory of justification is looming in the background of the response can shed light on the plausibility of certain theories of epistemic justification. (shrink)

This paper disputes the widely held view that one cannot establish the reliability of a belief-forming process with the use of belief's that are obtained by that very process since such self-dependent justification is circular. Harold Brown ([1993]) argued in this journal that some cases of self-dependent justification are legitimate despite their circularity. I argue instead that under appropriate construal many cases of self-dependent justification are not truly circular but are instances of ordinary Bayesian confirmation, and hence they can raise (...) the probability of the hypothesis as legitimately as any such confirmation does. I shall argue in particular that despite its dependence on perception we can use naturalized epistemology to confirm the reliability of a perceptual process without circularity. (shrink)

It is commonly held that epistemic standards for S ’s knowledge that p are affected by practical considerations, such as what is at stake in decisions that are guided by that p . I defend a particular view as to why this is, that is referred to as “pragmatic encroachment.” I then discuss a “new argument against miracles” that uses stakes considerations in order to explore the conditions under which stakes affect the level of epistemic support that is required for (...) knowledge. Finally, I generalize my results to include other religiously significant propositions such as “God exists” and “God does not exist.”. (shrink)

In this paper, I solve a puzzle generated by three conflicting claims about the relationship between faith, belief, and control: according to the Identity Thesis, faith is a type of belief, and according to Fideistic Voluntarism, we sometimes have control over whether or not we have faith, but according to Doxastic Involuntarism, we never have control over what we believe. To solve the puzzle, I argue that the Identity Thesis is true, but that either Fideistic Voluntarism or Doxastic Voluntarism is (...) false, depending on how we understand "control." I distinguish two notions of control: direct intention-based control and indirect reflective control. I argue that though we have direct intention-based control over neither belief nor faith, we have indirect reflective control over each of them. Moreover, indirect reflective control helps explain how we can be held accountable for each. (shrink)

Ernest Sosa's virtue perspectivism can be thought of as an attempt to capture as much as possible of the Cartesian project in epistemology while remaining within the framework of externalist fallibilism. I argue (a) that Descartes's project was motivated by a desire for intellectual stability and (b) that his project does not suffer from epistemic circularity. By contrast, Sosa's epistemology does entail epistemic circularity and, for this reason, proves unable to secure the sort of intellectual stability Descartes wanted. I then (...) argue that this leaves Sosa's epistemology vulnerable to an important kind of skepticism. (shrink)

Epistemic circularity occurs when a subject forms the belief that a faculty F is reliable through the use of F. Although this is often thought to be vicious, externalist theories generally don't rule it out. For some philosophers, this is a reason to reject externalism. However, Michael Bergmann defends externalism by drawing on the tradition of common sense in two ways. First, he concedes that epistemically circular beliefs cannot answer a subject's doubts about her cognitive faculties. But, he argues, subjects (...) don't have such doubts, so epistemically circular beliefs are rarely called upon to play this role. Second, following Thomas Reid, Bergmann argues that we have noninferential, though epistemically circular, knowledge that our faculties are reliable. I argue, however, that Bergmann's view is undermined by doubts a subject should have and that there is no plausible explanation for how we can have noninferential knowledge that our faculties are reliable. (shrink)

We are ignorant knowers. This paper proposes an information theoretic explanation of that fact. The explanation is a conjunction of three claims. First, that even in those dimensions where we are capable of picking up information, there is information that we don’t pick up. Second, that there can be dimensions of information for which we lack the capacity to pick up any information whatsoever. Third, that we don’t know whether the faculties and cognitive capacities we are endowed with process all (...) the information that they pick up. (shrink)

Moderate rationalists maintain that our rational intuitions provide us with prima facie justification for believing various necessary propositions. Such a claim is often criticized on the grounds that our having reliable rational intuitions about domains in which the truths are necessary is inexplicable in some epistemically objectionable sense. In this paper, I defend moderate rationalism against such criticism. I argue that if the reliability of our rational intuitions is taken to be contingent, then there is no reason to think that (...) our reliability is inexplicable. I also suggest that our reliability is, in fact, necessary, and that such necessary reliability neither admits of, nor requires, any explanation of the envisaged sort. (shrink)

Epistemic conservatism is the thesis that the mere holding of a belief confers some positive epistemic status on its content. Conservatism is widely criticized on the grounds that it conflicts with the main goal in epistemology to believe truths and disbelieve falsehoods. In this paper I argue for conservatism and defend it from objections. First, I argue that the objection to conservatism from the truth goal in epistemology fails. Second, I develop and defend an argument for conservatism from the perspectival (...) character of the truth goal. Finally, I examine several forceful challenges to conservatism and argue that these challenges are unsuccessful. The first challenge is that conservatism implies the propriety of assertions like ‘I believe p and this is part of my justification for it’. The second challenge argues that conservatism wrongly implies that the identity of an epistemic agent is relevant to the main goal of believing truths and disbelieving falsehoods. The last two challenges I consider are the ‘extra boost’ objection and the conversion objection. Each of these objections helps to clarify the nature of the conservative thesis. The upshot of the paper is that conservatism is an important and viable epistemological thesis. (shrink)

Pragmatist responses to radical skepticism do not receive much attention in contemporary analytic epistemology. This observation is my motivation for undertaking a search for a coherent pragmatist reply to radical doubt, one that can compete, in terms of clarity and sophistication, with the currently most popular approaches, such as contextualism and relevant alternatives theory. As my point of departure I take the texts of C. S. Peirce and William James. The Jamesian response is seen to consist in the application of (...) a wager argument to the skeptical issue in analogy with Pascal's wager. The Peircean strategy, on the other hand, is to attempt a direct rejection of one of the skeptic's main premises: that we do not know we are not deceived. I argue that while the Jamesian attempt is ultimately incoherent, Peirce's argument contains the core of a detailed and characteristically "pragmatic" rebuttal of skepticism, one that deserves to be taken seriously in the contemporary debate. (shrink)

This paper analyzes the apraxia argument in Cicero’s Academica. It proposes that the argument assumes two modes: the evidential mode maintains that skepticism is false, while the pragmatic claims that it is disadvantageous. The paper then develops a tension between the two modes, and concludes by exploring some differences between ancient and contemporary skepticism.

A skeptic claims that I do not have knowledge of the external world. It has been thought that the skeptic reaches this conclusion because she employs unusually stringent standards for knowledge. But the skeptic does not employ unusually high standards for knowledge. Rather, she employs unusually restrictive standards of evidence. Thus, her claim that we lack knowledge of the external world is supported by considerations that would equally support the claim that we lack evidence for our beliefs about the external (...) world. These considerations do not threaten the truth of our ordinary attributions of evidence, however, for such attributions are context-sensitive in their semantics. It is argued that this solution to the problem of the external world enjoys all of the benefits, and suffers none of the problems, of other solutions to the problem of the external world. (shrink)

According to a doctrine that I call “Cartesianism”, knowledge – at least the sort of knowledge that inquirers possess – requires having a reason for belief that is reflectively accessible as such. I show that Cartesianism, in conjunction with some plausible and widely accepted principles, entails the negation of a popular version of Fallibilism. I then defend the resulting Cartesian Infallibilist position against popular objections. My conclusion is that if Cartesianism is true, then Descartes was right about this much: for (...) S to know that p, S must have reasons for believing that p which are such that S can know, by reflection alone, that she has those reasons, and that she could not possibly have those reasons if p is not true. Where Descartes went wrong was in thinking that our ordinary, fallible, non-theologically grounded sources of belief (e.g., perception, memory, testimony), cannot provide us with such reasons. (shrink)

Suppose that time t is just a few moments from now. And suppose that the proposition that Jones sits at t was true a thousand years ago. Does the thousand-years-ago truth of that proposition imply that Jones's upcoming sitting at t will not be free? This article argues that it does not. It also argues that Jones even now has a choice about the thousand-years-ago truth of that Jones sits at t . Those arguments do not require the complex machinery (...) of Ockhamism, with its distinction between hard facts and soft facts; indeed, those arguments do not require any complex machinery at all. Instead, those arguments are built on an uncontroversial understanding of the idea that truth depends on the world. In the final section of the article, those arguments are extended to show that foreknowledge of an action does not threaten that action's freedom. (shrink)

That bootstrapping and Moorean reasoning fail to instantiate persuasive argumentation is an often informally presented but not systematically developed view. In this paper, I will argue that this unpersuasiveness is not determined by principles of justification transmission but by two straightforward principles of rationality, understood as a concept of internal coherence. First, it is rational for S to believe the conclusion of an argument because of the argument, only if S believes sufficiently many premises of the argument. Second, if S (...) doubts that a source O is reliable and believes that information i is delivered by O, then S rationally suspends judgment about the truth of i. This paper aims to accomplish two tasks. First, it provides a thorough analysis of why bootstrapping argumentation is not an instance of rational persuasion. Second, it contains a more general theory about preconditions and limits of persuasive argumentation. (shrink)

I argue that beliefs about what appears possible are justified in much the same way as beliefs about what appears actual. I do so by chisholming, and then modalizing, the epistemic principle associated with phenomenal conservatism. The principle is tested against a number of examples, and it gives the intuitively correct results. I conclude by considering how it can be used to defend two controversial modal arguments, a Cartesian argument for dualism and an ontological argument for the existence of God.

Although Alston believed epistemically circular arguments were able to justify their conclusions, he was also disquieted by them. We will argue that Alston was right to be disquieted. We explain Alston’s view of epistemic circularity, the considerations that led him to accept it, and the purposes he thought epistemically circular arguments could serve. We then build on some of Alston’s remarks and introduce further limits to the usefulness of such arguments and introduce a new problem that stems from those limits. (...) The upshot is that adopting Alston’s view that epistemically circular arguments can be used to justify their conclusions is more costly than even he thought. (shrink)

In this paper, I raise two questions about epistemic commitments, and thus, indirectly, about our epistemic agency. Can we rationally defend such commitments when challenged to do so? And if so, how?

Can we show that our senses are reliable sources of information about the world? To show this, we need to establish that most of our perceptual judgments have been true. But we cannot determine these inductive instances without relying upon sense perception. Thus, it seems, we cannot establish the reliability of sense perception by means of an argument without falling into epistemic circularity. In this paper, I argue that this consequence is not an epistemological disaster. For this purpose, I defend (...) a normative claim that it is reasonable to accept the general reliability of our perceptual judgments, instead of a factual claim that our perceptual judgments are generally reliable. More specifically, I offer a normative practical argument which explains why it is reasonable to accept the general reliability of our perceptual judgments, even though we cannot establish the general reliability of our perceptual judgments by means of theoretical reasoning. (shrink)

The problem of epistemic circularity involved in justifying fundamental epistemic principles is one of the fundamental problems of epistemology. One important way out of this problem is a Sellarsian social practice theory of justification, according to which we are justified in accepting an epistemic principle if we can answer all objections raised against it in our social practice of demanding justification and responding to such demands. The main goal of this paper is to show that this social practice theory can (...) accomplish better than its rival theories, such as Alston’s doxastic practice approach, Sosa’s reliabilist virtue epistemology, and Wright’s entitlement theory, by making comparisons with these influential theories. (shrink)

In this paper, I argue that what underlies internalism about justification is a rationalist conception of justification, not a deontological conception of justification, and I argue for the plausibility of this rationalist conception of justification. The rationalist conception of justification is the view that a justified belief is a belief that is held in a rational way; since we exercise our rationality through conscious deliberation, the rationalist conception holds that a belief is justified iff a relevant possible instance of conscious (...) deliberation would endorse the belief. The importance of conscious deliberation stems from its role in guiding us in acquiring true beliefs: whereas the externalist holds that if we wish to acquire true beliefs, we have to begin by assuming that some of our usual methods of belief formation generally provide us with true beliefs, the intemalist holds that if we form beliefs by conscious deliberation, we can be conscious of reasons for thinking that our beliefs are true. Conscious deliberation can make us conscious of reasons because it proceeds via rational intuitions. I argue that despite the fallibility of rational intuition, rational intuitions do enable us to become conscious of reasons for belief. (shrink)

There are a number of debates that are relevant to questions concerning objectivity in science. One of the eldest, and still one of the most intensely fought, is the debate over epistemic relativism. —All forms of epistemic relativism commit themselves to the view that it is impossible to show in a neutral, non-question-begging, way that one “epistemic system”, that is, one interconnected set of epistemic standards, is epistemically superior to others. I shall call this view “No-metajustification”. No-metajustification is commonly taken (...) to deny the objectivity of standards. In this paper I shall discuss two currently popular attempts to attack “No-metajustification”. The first attempt attacks no-metajustification by challenging a particular strategy of arguing in its defence: this strategy involves the ancient Pyrrhonian “Problem of the Criterion”. The second attempt to refute No-metajustification targets its metaphysical underpinning: to wit, the claim that there are, or could be, several fundamentally different and irreconcilable epistemic systems. I shall call this assumption “Pluralism”. I shall address three questions with respect to these attempts to refute epistemic relativism by attacking no-metajustification: Can the epistemic relativist rely on the Problem of the Criterion in support of No-metajustification? Is a combination of Chisholmian “particularism” and epistemic naturalism an effective weapon against No-metajustification? And is Pluralism a defensible assumption? (shrink)

This essay defends a principle that promises to help illuminate the nature of reflective knowledge. The principle in question belongs to a broader category called knows-knows principles, or KK principles for short. Such principles say that if you know some proposition, then you're in a position to know that you know it.KK principles were prominent among various historical philosophers and can be fruitfully integrated with many views in contemporary epistemology and beyond—and yet almost every contemporary analytic epistemologist thinks that they (...) are false.Regarding their historical pedigree: they've been endorsed by Plato, Aristotle, Augustine, Averroes, Aquinas, Spinoza, and Schopenhauer, among others.1Regarding... (shrink)

Moore’s paradox supports the principle of “metacoherence”, i.e., that if one categorically believes that P, one is committed to accepting that one knows that P. The principle raises puzzles about how, when one has justification for P, one also has justification for the claim that one knows P. I reject a skeptical answer as well as a bootstrapping answer, and I suggest that we typically have independent justification for the claim that we know P.

According to Antonia Barkes version of contextualism, epistemic contextualism, a context is defined by a method and its associated assumptions. The subject has to make the assumption that the method is adequate or reliable and that good working conditions hold in order to arrive at knowledge by employing the method. I will criticize Barkes claim that epistemic contextualism can provide a more satisfactory explanation or motivation for context shifts than conversational contextualism (in particular, David Lewiss contextualism). Two more points of (...) criticizm will be presented, which are meant to show that epistemic contextualism presupposes epistemic internalism, and that (epistemic) contextualism leads to an implausible view about which parameters the special achievement that is constitutive of knowledge depends on. I suggest that, contra (epistemic) contextualism, knowledge is a more robust phenomenon that does not depend on whether anyone calls into question any assumptions or raises skeptical doubts in conversation or in his or her mind (as, for example, Fred Dretskes account says). I indicate how this can be reconciled with the phenomenon that knowledge attributions are somewhat unstable and seemingly context-dependent. (shrink)