Can you rationally double-check what you already know? In this paper, I argue that you can. Agents can know that something is true and rationally double-check it at the very same time. I defend my position by considering a wide variety of cases where agents double-check their beliefs to gain epistemic improvements beyond knowledge. These include certainty, epistemic resilience, and sensitivity to error. Although this phenomenon is widespread, my proposal faces two types of challenges. First, some have defended ignorance norms, (...) on which agents are only allowed to inquire about things they don't already know. Second – motivated by strong conceptions of belief or pragmatic encroachment – some have argued that double-checking destroys knowledge. I argue that these competing views fail to capture both the epistemic value of double-checking and the many reasons why agents might double-check. Moreover, they rely on overly strong assumptions about what inquiry, knowledge, or belief requires. Finally, I marshal linguistic data in favor of the compatibility of knowledge and double-checking. (shrink)

How is what we believe related to how we act? That depends on what we mean by ‘believe’. On the one hand, there is what we're sure of: what our names are, where we were born, whether we are sitting in front of a screen. Surety, in this sense, is not uncommon — it does not imply Cartesian absolute certainty, from which no possible course of experience could dislodge us. But there are many things that we think that we are (...) not sure of. For example, you might think that it will rain sometime this month, but not be sure that it will. Both what we're sure of and what we think have important normative connections to action. But the connections are quite different. This paper explores these issues with respect to assertion, inquiry, and decision making. We conclude by arguing that there is no theoretically significant notion of ‘full belief’ intermediate in strength between thinking and being sure. (shrink)

Much of the recent work on epistemology of inquiry defends two related theses. First, inquiry into a question rationally prohibits believing an answer to that question. Second, knowledge is the aim of inquiry. I develop a series of cases which indicate that inquiry is not as narrow as these views suggest. These cases can be accommodated if we take a broader approach and understand inquiry as aiming at epistemic improvement, described more generally. This approach captures a wider range of inquiring (...) phenomena because it accounts for forms of epistemic improvement that fall short of, or go beyond, coming to know the answer to a question. (shrink)

In Fallibilism: Evidence and Knowledge, Jessica Brown identifies a number of problems for the so-called knowledge view of justification. According to this view, we cannot justifiably believe what we do not know. Most epistemologists reject this view on the grounds that false beliefs can be justified if, say, supported by the evidence or produced by reliable processes. We think this is a mistake and that many epistemologists are classifying beliefs as justified because they have properties that indicate that something should (...) be excused. Brown thinks that previous attempts to make this case have been unsuccessful. While the difficulties Brown points to are genuine, I think they show that attempts to explain a classificatory judgment haven't been successful. Still, I would argue that the classification is correct. We need a better explanation of this classificatory judgment. I will try to clarify the justification-excuse distinction and explain why it's a mistake to insist that beliefs that violate epistemic norms might be justified. Just as it's possible for a rational agent to act without justification in spite of her best intentions, it's possible that a rational thinker who follows the evidence and meets our expectations might nevertheless believe without sufficient justification. If our justified beliefs are supposed to guide us in deciding what to do, we probably should draw on discussions from morality and the law about the justification/excuse distinction to inform our understanding of the epistemic case. (shrink)

I defend the thesis that the constitutive aim of inquiring into some question, Q, is improving one’s epistemic standing with respect to Q. Call this the epistemic-improvement view. I consider and ultimately reject two alternative accounts of the constitutive aim of inquiry—namely, the thesis that inquiry aims at knowledge and the thesis that inquiry aims at belief—and I use my criticisms as a foil for clarifying and motivating the epistemic-improvement view. I also consider and reject a pair of normative theses (...) about when inquiry goes awry or is inappropriate. The first is the normative thesis defended by Dennis Whitcomb who claims that inquiry goes awry if it culminates in a belief that falls short of knowledge and that one should not inquire into Q if one already knows the answer to Q. The second is the normative thesis defended by Jane Friedman who claims that one should not inquire into Q if one already believes some complete answer to Q. (shrink)

This paper considers some puzzling knowledge ascriptions and argues that they present prima facie counterexamples to credence, belief, and justification conditions on knowledge, as well as to many of the standard meta-semantic assumptions about the context-sensitivity of ‘know’. It argues that these ascriptions provide new evidence in favor of contextualist theories of knowledge—in particular those that take the interpretation of ‘know’ to be sensitive to the mechanisms of constraint.

A puzzle arises when combining two individually plausible, yet jointly incompatible, norms of inquiry. On the one hand, it seems that one shouldn’t inquire into a question while believing an answer to that question. But, on the other hand, it seems rational to inquire into a question while believing its answer, if one is seeking confirmation. Millson (2021), who has recently identified this puzzle, suggests a possible solution, though he notes that it comes with significant costs. I offer an alternative (...) solution, which doesn’t involve these costs. The best way to resolve the puzzle is to reject the prohibition on inquiring into a question while believing an answer to it. Resolving the puzzle in this way makes salient two fruitful areas in the epistemology of inquiry which merit further investigation. The first concerns the nature of the inquiring attitudes and the second concerns the aim(s) of inquiry. (shrink)

What sort of epistemic positions are compatible with inquiries driven by interrogative attitudes like wonder and puzzlement? The ignorance norm provides a partial answer: interrogative attitudes directed at a particular question are never compatible with knowledge of the question’s answer. But some are tempted to think that interrogative attitudes are incompatible with weaker positions like belief as well. This paper defends that the ignorance norm is exhaustive. All epistemic positions weaker than knowledge directed at the answer to a question are (...) compatible with having an interrogative attitude towards that question. We offer two arguments for this conclusion. The first is based on considerations about the role of hedging in inquiry. The second is conditional on considerations related to the aim of inquiry as a goal-directed activity. (shrink)

Formal models of appearance and reality have proved fruitful for investigating structural properties of perceptual knowledge. This paper applies the same approach to epistemic justification. Our central goal is to give a simple account of The Preface, in which justified belief fails to agglomerate. Following recent work by a number of authors, we understand knowledge in terms of normality. An agent knows p iff p is true throughout all relevant normal worlds. To model The Preface, we appeal to the normality (...) of error. Sometimes, it is more normal for reality and appearance to diverge than to match. We show that this simple idea has dramatic consequences for the theory of knowledge and justification. Among other things, we argue that a proper treatment of The Preface requires a departure from the internalist idea that epistemic justification supervenes on the appearances and the widespread idea that one knows most when free from error. (shrink)

This paper is about guessing: how people respond to a question when they aren’t certain of the answer. Guesses show surprising and systematic patterns that the most obvious theories don’t explain. We argue that these patterns reveal that people aim to optimize a tradeoff between accuracy and informativity when forming their guess. After spelling out our theory, we use it to argue that guessing plays a central role in our cognitive lives. In particular, our account of guessing yields new theories (...) of belief, assertion, and the conjunction fallacy—the psychological finding that people sometimes rank a conjunction as more probable than one of its conjuncts. More generally, we suggest that guessing helps explain how boundedly rational agents like us navigate a complex, uncertain world. (shrink)

Call the norms of inquiry zetetic norms. How are zetetic norms related to epistemic norms? At first glance, they seem quite closely connected. Aren't epistemic norms norms that bind inquirers qua inquirers? And isn't epistemology the place to look for a normative theory of inquiry? While much of this thought seems right, this paper argues that the relationship between the epistemic and the zetetic is not as harmonious as one might have thought and liked. In particular, this paper argues that (...) some familiar contemporary epistemic norms are in tension with, and even in conflict with, central zetetic norms. (shrink)

According to the dogmatist, knowing p makes it rational to disregard future evidence against p. The standard response to the dogmatist holds that knowledge is defeasible: acquiring evidence against something you know undermines your knowledge. However, this response leaves a residual puzzle, according to which knowledge makes it rational to intend to disregard future counterevidence. I argue that we can resolve this residual puzzle by turning to an unlikely source: Kavka’s toxin puzzle. One lesson of the toxin puzzle is that (...) it is irrational to intend to do that which you know will be irrational. This yields a simple reply to the dogmatist: it is irrational to intend to disregard future evidence because you can know in advance that it will be irrational to do so. (shrink)

This paper formulates some paradoxes of inductive knowledge. Two responses in particular are explored: According to the first sort of theory, one is able to know in advance that certain observations will not be made unless a law exists. According to the other, this sort of knowledge is not available until after the observations have been made. Certain natural assumptions, such as the idea that the observations are just as informative as each other, the idea that they are independent, and (...) that they increase your knowledge monotonically (among others) are given precise formulations. Some surprising consequences of these assumptions are drawn, and their ramifications for the two theories examined. Finally, a simple model of inductive knowledge is offered, and independently derived from other principles concerning the interaction of knowledge and counterfactuals. (shrink)

In a series of recent papers, Jane Friedman has argued that attitudes like wondering, enquiring, and suspending judgement are question-directed and have the function of moving someone from a position of ignorance to one of knowledge. Call such attitudes interrogative attitudes. Friedman insists that all IAs are governed by the following Ignorance Norm: Necessarily, if one knows Q at t, then one ought not have an IA towards Q at t. However, I argue that key premisses in Friedman’s argument actually (...) point towards an opposing conclusion; namely, that IAs are not governed by the Ignorance Norm, and IAs have functions other than moving someone from a position of ignorance to one of knowledge. I conclude that the Ignorance Norm should be rejected. (shrink)

There is a fundamental disagreement about which norm regulates assertion. Proponents of factive accounts argue that only true propositions are assertable, whereas proponents of non-factive accounts insist that at least some false propositions are. Puzzlingly, both views are supported by equally plausible (but apparently incompatible) linguistic data. This paper delineates an alternative solution: to understand truth as the aim of assertion, and pair this view with a non-factive rule. The resulting account is able to explain all the relevant linguistic data, (...) and finds independent support from general considerations about the differences between rules and aims. (shrink)

In this paper I look at belief and degrees of belief through the lens of inquiry. I argue that belief and degrees of belief play different roles in inquiry. In particular I argue that belief is a “settling” attitude in a way that degrees of belief are not. Along the way I say more about what inquiring amounts to, argue for a central norm of inquiry connecting inquiry and belief and say more about just what it means to have an (...) inquiry or question settled. (shrink)

The Lockean Thesis says that you must believe p iff you’re sufficiently confident of it. On some versions, the 'must' asserts a metaphysical connection; on others, it asserts a normative one. On some versions, 'sufficiently confident' refers to a fixed threshold of credence; on others, it varies with proposition and context. Claim: the Lockean Thesis follows from epistemic utility theory—the view that rational requirements are constrained by the norm to promote accuracy. Different versions of this theory generate different versions of (...) Lockeanism; moreover, a plausible version of epistemic utility theory meshes with natural language considerations, yielding a new Lockean picture that helps to model and explain the role of beliefs in inquiry and conversation. Your beliefs are your best guesses in response to the epistemic priorities of your context. Upshot: we have a new approach to the epistemology and semantics of belief. And it has teeth. It implies that the role of beliefs is fundamentally different than many have thought, and in fact supports a metaphysical reduction of belief to credence. (shrink)

By means of an example, shows the possibility of beliefs that are separately rational whilst together inconsistent.

Dorr et al. present a case that poses a challenge for a number of plausible principles about knowledge and objective chance. Implicit in their discussion is an interesting new argument against KK, the principle that anyone who knows p is in a position to know that they know p. We bring out this argument, and investigate possible responses for defenders of KK, establishing new connections between KK and various knowledge-chance principles.

An explanation is given of why it is in the nature of inquiry into whether or not p that its aim is fully achieved only if one comes to know that p or to know that not-p and, further, comes to know how one knows, either way. In the absence of the latter one is in no position to take the inquiry to be successfully completed or to vouch for the truth of the matter in hand. An upshot is that (...) although knowledge matters because truth matters this should not be understood to mean that knowledge matters because true belief matters. (shrink)

An important question in epistemology is whether the KK principle is true, i.e., whether an agent who knows that p is also thereby in a position to know that she knows that p. We explain how a “transparency” account of self-knowledge, which maintains that we learn about our attitudes towards a proposition by reflecting not on ourselves but rather on that very proposition, supports an affirmative answer. In particular, we show that such an account allows us to reconcile a version (...) of the KK principle with an “externalist” or “reliabilist” conception of knowledge commonly thought to make that principle particularly problematic. (shrink)

This paper extends several themes from recent work on norms of assertion. It does as much by applying those themes to the speech act of asking. In particular, it argues for the view that there is a species of asking which is governed by a certain norm, a norm to the effect that one should ask a question only if one doesn’t know its answer.

In this paper I argue that suspension of judgment is intimately tied to inquiry and in particular that one is suspending judgment about some question if and only if one is inquiring into that question.

Many philosophers have argued that "degree of belief" or "credence" is a more fundamental state grounding belief. Many other philosophers have been skeptical about the notion of "degree of belief", and take belief to be the only meaningful notion in the vicinity. This paper shows that one can take belief to be fundamental, and ground a notion of "degree of belief" in the patterns of belief, assuming that an agent has a collection of beliefs that isn't dominated by some other (...) collection in terms of the overall balance of truth and falsity that it could contain. (shrink)

In this paper I present a qualified defense of the KK principle. In section one I introduce two popular arguments against the KK principle, along with an example in which these arguments seem to prove too much. In section two I provide a simple formal model of knowledge in which KK holds, and which I argue provides an attractive analysis of the example from section one. I go on argue that when this model is combined with contextualism, we can retain (...) our attractive analysis of the example, while also explaining away the appeal of the aforementioned arguments against KK. I use the same maneuver contextualists have used to defend epistemic closure principles--I argue that KK holds within contexts, but can fail across contexts. (shrink)

In this book, Ernest Sosa explains the nature of knowledge through an approach originated by him years ago, known as virtue epistemology. Here he provides the first comprehensive account of his views on epistemic normativity as a form of performance normativity on two levels. On a first level is found the normativity of the apt performance, whose success manifests the performer's competence. On a higher level is found the normativity of the meta-apt performance, which manifests not necessarily first-order skill or (...) competence but rather the reflective good judgment required for proper risk assessment. Sosa develops this bi-level account in multiple ways, by applying it to issues much disputed in recent epistemology: epistemic agency, how knowledge is normatively related to action, the knowledge norm of assertion, and the Meno problem as to how knowledge exceeds merely true belief. A full chapter is devoted to how experience should be understood if it is to figure in the epistemic competence that must be manifest in the truth of any belief apt enough to constitute knowledge. Another takes up the epistemology of testimony from the performance-theoretic perspective. Two other chapters are dedicated to comparisons with ostensibly rival views, such as classical internalist foundationalism, a knowledge-first view, and attributor contextualism. The book concludes with a defense of the epistemic circularity inherent in meta-aptness and thereby in the full aptness of knowing full well. (shrink)

Recent authors have drawn attention to a new kind of defeating evidence commonly referred to as higher-order evidence. Such evidence works by inducing doubts that one’s doxastic state is the result of a flawed process – for instance, a process brought about by a reason-distorting drug. I argue that accommodating defeat by higher-order evidence requires a two-tiered theory of justification, and that the phenomenon gives rise to a puzzle. The puzzle is that at least in some situations involving higher-order defeaters (...) the correct epistemic rules issue conflicting recommendations. For instance, a subject ought to believe p, but she ought also to suspend judgment in p. I discuss three responses. The first resists the puzzle by arguing that there is only one correct epistemic rule, an Über-rule. The second accepts that there are genuine epistemic dilemmas. The third appeals to a hierarchy or ordering of correct epistemic rules. I spell out problems for all of these responses. I conclude that the right lesson to draw from the puzzle is that a state can be epistemically rational or justified even if one has what looks to be strong evidence to think that it is not. As such, the considerations put forth constitute a non question-begging argument for a kind of externalism. (shrink)

One thousand fair causally isolated coins will be independently flipped tomorrow morning and you know this fact. I argue that the probability, conditional on your knowledge, that any coin will land tails is almost 1 if that coin in fact lands tails, and almost 0 if it in fact lands heads. I also show that the coin flips are not probabilistically independent given your knowledge. These results are uncomfortable for those, like Timothy Williamson, who take these probabilities to play a (...) central role in their theorizing. (shrink)

It is common orthodoxy among internalists and externalists alike that knowledge is lost or defeated in situations involving misleading evidence of a suitable kind. But making sense of defeat has seemed to present a particular challenge for those who reject an internalist justification condition on knowledge. My main aim here is to argue that externalists ought to take seriously a view on which knowledge can be retained even in the face of strong seemingly defeating evidence. As an instructive example, I (...) first discuss whether a theory on which knowledge is belief that is safe from error has the resources for accommodating defeat. I argue that beliefs retained in defeat cases need not be unsafe or true in some accidental way. I then discuss externalist strategies for explaining why we have incorrect intuitions about defeat. The notion of an epistemically reasonable subject plays a central role in my theory. Reasonable subjects adopt general strategies that are good for acquiring true belief and knowledge across a wide range of normal cases, but stubbornly retaining belief in the face of new evidence does not reflect such policies. I argue that though the methods employed by subjects who fail to adjust their beliefs in defeat cases may be perfectly good, they are not good methods to adopt, as their adoption is accompanied by bad dispositions. What emerges is a view on which a subject can know despite being unreasonable, and despite failing to manifest dispositions to know across normal cases. Unreasonable subjects are genuinely criticisable, but like almost anything, knowledge can sometimes be achieved in the absence of a good general strategy. (shrink)

We present and discuss a counterexample to the following plausible principle: if you know that a coin is fair, and for all you know it is going to be flipped, then for all you know it will land tails.

It is tempting to posit an intimate relationship between belief and assertion. The speech act of assertion seems like a way of transferring the speaker’s belief to his or her audience. If this is right, then you might think that the evidential warrant required for asserting a proposition is just the same as the warrant for believing it. We call this thesis entitlement equality. We argue here that entitlement equality is false, because our everyday notion of belief is unambiguously a (...) weak one. Believing something is true, we argue, is compatible with having relatively little confidence in it. Asserting something requires something closer to complete confidence. Specifically, we argue that believing a proposition merely requires thinking it likely, but that thinking that a proposition is likely does not entitle one to assert it. This conclusion conflict with a standard view that ‘full belief’ is the central commonsense non-factive attitude. (shrink)

The core of Anthony Brueckner’s critique in ‘Knowledge, Evidence, and Skepticism according to Williamson’ is his claim in section 5 that my account of perceptual knowledge has an unacceptable consequence. My reply will concentrate on that claim and largely ignore the rest of Brueckner’s interesting discussion, for it is easy to check that the claim is essential to Brueckner’s argument against my analysis of skepticism and evidence.

Abstract In this paper I undertake an in-depth examination of an oft mentioned but rarely expounded upon state: suspended judgment. While traditional epistemology is sometimes characterized as presenting a “yes or no” picture of its central attitudes, in fact many of these epistemologists want to say that there is a third option: subjects can also suspend judgment. Discussions of suspension are mostly brief and have been less than clear on a number of issues, in particular whether this third option should (...) be thought of as an attitude or not. In this paper I argue that suspended judgment is (or at least involves) a genuine attitude. Content Type Journal Article Pages 1-17 DOI 10.1007/s11098-011-9753-y Authors Jane Friedman, St Catherine’s College, University of Oxford, Oxford, OX1 3UJ UK Journal Philosophical Studies Online ISSN 1573-0883 Print ISSN 0031-8116. (shrink)

This paper explores the nature of curiosity from an epistemological point of view. First it motivates this exploration by explaining why epistemologists do and should care about what curiosity is. Then it surveys the relevant literature and develops a particular approach.

This paper brings together two positions that for the most part have been developed and defended independently of one another: contextualism about knowledge attributions and the knowledge account of assertion.

Knowledge and Lotteries is organized around an epistemological puzzle: in many cases, we seem consistently inclined to deny that we know a certain class of propositions, while crediting ourselves with knowledge of propositions that imply them. In its starkest form, the puzzle is this: we do not think we know that a given lottery ticket will be a loser, yet we normally count ourselves as knowing all sorts of ordinary things that entail that its holder will not suddenly acquire a (...) large fortune. After providing a number of specific and general characterizations of the puzzle, Hawthorne carefully examines the competing merits of candidate solutions. In so doing, he explores a number of central questions concerning the nature and importance of knowledge, including the relationship of knowledge to assertion and practical reasoning, the status of epistemic closure principles, the merits of various brands of scepticism, the prospects for a contextualist account of knowledge, and the potential for other sorts of salience-sensitive accounts. Along the way, he offers a careful treatment of pertinent issues at the foundations of semantics. His book will be of interest to anyone working in the field of epistemology, as well as to philosophers of language. (shrink)

§I schematises the evidence for an understanding of ‘know’ and other terms of epistemic appraisal that embodies contextualism or subject-sensitive invariantism, and distinguishes between those two approaches. §II argues that although the cases for contextualism and sensitive invariantism rely on a principle of charity in the interpretation of epistemic claims, neither approach satisfies charity fully, since both attribute metalinguistic errors to speakers. §III provides an equally charitable anti-sceptical insensitive invariantist explanation of much of the same evidence as the result of (...) psychological bias caused by salience effects. §IV suggests that the explanation appears to have implausible consequences about practical reasoning, but also that applications of contextualism or sensitive invariantism to the problem of scepticism have such consequences. §V argues that the inevitable difference between appropriateness and knowledge of appropriateness in practical reasoning, closely related to the difference between knowledge and knowledge of knowledge, explains the apparent implausibility. (shrink)

Judging by our folk appraisals, then, knowledge and action are intimately related. The theories of rational action with which we are familiar leave this unexplained. Moreover, discussions of knowledge are frequently silent about this connection. This is a shame, since if there is such a connection it would seem to constitute one of the most fundamental roles for knowledge. Our purpose in this paper is to rectify this lacuna, by exploring ways in which knowing something is related to rationally acting (...) upon it, defending one particular proposal against anticipated objections. (shrink)

I motivate and briefly sketch a linguistic theory of vagueness, on which the notion of indeterminacy is understood in terms of the conventions of language: a sentence is indeterminate iff the conventions of language either forbid asserting it and forbid asserting its negation, under the circumstances, or permit asserting either. I then consider an objection that purports to show that if this theory (or, as far as I can see, any other theory of vagueness that deserved the label "linguistic" were (...) true, there would be no such thing as indeterminacy. I respond to this objection by arguing on independent grounds against its main premise, the widely-accepted claim that if it is indeterminate whether P, no human being knows whether P. I defend an alternative view according to which, when it is indeterminate whether P, it is often also indeterminate whether we know that P. (shrink)

The pragmatic character of the Dutch book argument makes it unsuitable as an "epistemic" justification for the fundamental probabilist dogma that rational partial beliefs must conform to the axioms of probability. To secure an appropriately epistemic justification for this conclusion, one must explain what it means for a system of partial beliefs to accurately represent the state of the world, and then show that partial beliefs that violate the laws of probability are invariably less accurate than they could be otherwise. (...) The first task can be accomplished once we realize that the accuracy of systems of partial beliefs can be measured on a gradational scale that satisfies a small set of formal constraints, each of which has a sound epistemic motivation. When accuracy is measured in this way it can be shown that any system of degrees of belief that violates the axioms of probability can be replaced by an alternative system that obeys the axioms and yet is more accurate in every possible world. Since epistemically rational agents must strive to hold accurate beliefs, this establishes conformity with the axioms of probability as a norm of epistemic rationality whatever its prudential merits or defects might be. (shrink)

This paper uses the knowledge account of assertion (KAA) in defense of epistemological contextualism. Part 1 explores the main problem afflicting contextualism, what I call the "Generality Objection." Part 2 presents and defends both KAA and a powerful new positive argument that it provides for contextualism. Part 3 uses KAA to answer the Generality Objection, and also casts other shadows over the prospects for anti-contextualism.

Fred Dretske; XI*—Introspection, Proceedings of the Aristotelian Society, Volume 94, Issue 1, 1 June 1994, Pages 263–278, https://doi.org/10.1093/aristotelian/9.

You omega know something when you know it, and know that you know it, and know that you know that you know it, and so on. This paper first argues that omega knowledge matters, in the sense that it is required for rational assertion, action, inquiry, and belief. The paper argues that existing accounts of omega knowledge face major challenges. One account is skeptical, claiming that we have no omega knowledge of any ordinary claims about the world. Another account embraces (...) the KK thesis, and identifies knowledge with omega knowledge. This position faces counterexamples, and struggles to make sense of inexact knowledge. The paper then develops a new account of knowledge, by proposing the principle of Reflective Luminosity: if you know that you know something, then you omega know it. I argue that Reflective Luminosity allows for omega knowledge while avoiding the problems for KK. (shrink)

There is a large literature exploring how accuracy constrains rational degrees of belief. This paper turns to the unexplored question of how accuracy constrains knowledge. We begin by introducing a simple hypothesis: increases in the accuracy of an agent’s evidence never lead to decreases in what the agent knows. We explore various precise formulations of this principle, consider arguments in its favour, and explain how it interacts with different conceptions of evidence and accuracy. As we show, the principle has some (...) noteworthy consequences for the wider theory of knowledge. First, it implies that an agent cannot be justified in believing a set of mutually inconsistent claims. Second, it implies the existence of a kind of epistemic blindspot: it is not possible to know that one’s evidence is misleading. (shrink)