A critical review of “Gettier” cases and theoretical attempts to solve “the” "Gettier" "problem".

Philosophers have debated whether it is possible to knowledgeably infer a conclusion from a false premise. For example, if a fan believes that the actress’s dress is blue, but the dress is actually green, can the fan knowledgeably infer “the dress is not red” from “the dress is blue”? One aspect of this debate concerns what the intuitively correct verdict is about specific cases such as this. Here I report a simple behavioral experiment that helps answer this question. The main (...) finding is that people attribute knowledge in cases where a true conclusion is inferred from a false premise. People did this despite judging that the premise was false and unknown. People also viewed the agent as inferring the conclusion from the premise. In closely matched conditions where the conclusion was false, people did not attribute knowledge of the conclusion. These results support the view that the ordinary knowledge concept includes in its extension cases of knowledge inferred from false premises. (shrink)

Vagueness provides the first comprehensive examination of a topic of increasing importance in metaphysics and the philosophy of logic and language. Timothy Williamson traces the history of this philosophical problem from discussions of the heap paradox in classical Greece to modern formal approaches such as fuzzy logic. He illustrates the problems with views which have taken the position that standard logic and formal semantics do not apply to vague language, and defends the controversial realistic view that vagueness is a kind (...) of ignorance--that there really is a grain of sand whose removal turns a heap into a non-heap, but we cannot know which one it is. (shrink)

Intuitively, there is a difference between knowledge and mere belief. Contemporary philosophical work on the nature of this difference has focused on scenarios known as “Gettier cases.” Designed as counterexamples to the classical theory that knowledge is justified true belief, these cases feature agents who arrive at true beliefs in ways which seem reasonable or justified, while nevertheless seeming to lack knowledge. Prior empirical investigation of these cases has raised questions about whether lay people generally share philosophers’ intuitions about these (...) cases, or whether lay intuitions vary depending on individual factors (e.g. ethnicity) or factors related to specific types of Gettier cases (e.g. cases that include apparent evidence). We report an experiment on lay attributions of knowledge and justification for a wide range of Gettier Cases and for a related class of controversial cases known as Skeptical Pressure cases, which are also thought by philosophers to elicit intuitive denials of knowledge. Although participants rated true beliefs in Gettier and Skeptical Pressure cases as being justified, they were significantly less likely to attribute knowledge for these cases than for matched true belief cases. This pattern of response was consistent across different variations of Gettier cases and did not vary by ethnicity or gender, although attributions of justification were found to be positively related to measures of empathy. These findings therefore suggest that across demographic groups, laypeople share similar epistemic concepts with philosophers, recognizing a difference between knowledge and justified true belief. (shrink)

This classic remains one of Karl Popper's most wide-ranging and popular works, notable not only for its acute insight into the way scientific knowledge grows, but also for applying those insights to politics and to history.

In “Why the generality problem is everybody’s problem,” Michael Bishop argues that every theory of justification needs a solution to the generality problem. He contends that a solution is needed in order for any theory to be used in giving an acceptable account of the justificatory status of beliefs in certain examples. In response, first I will describe the generality problem that is specific to process reliabilism and two other sorts of problems that are essentially the same. Then I will (...) argue that the examples that Bishop presents pose no such problem for some theories. I will illustrate the exempt theories by describing how an evidentialist view can account for the justification in the examples without having any similar problem. It will be clear that other views about justification are likewise unaffected by anything like the generality problem. (shrink)

This paper advances the debate over the question whether false beliefs may nevertheless have warrant, the property that yields knowledge when conjoined with true belief. The paper’s first main part—which spans Sections 2–4—assesses the best argument for Warrant Infallibilism, the view that only true beliefs can have warrant. I show that this argument’s key premise conflicts with an extremely plausible claim about warrant. Sections 5–6 constitute the paper’s second main part. Section 5 presents an overlooked puzzle about warrant, and uses (...) that puzzle to generate a new argument for Warrant Fallibilism, the view that false beliefs can have warrant. Section 6 evaluates this pro-Fallibilism argument, finding ultimately that it defeats itself in a surprising way. I conclude that neither Infallibilism nor Fallibilism should now constrain theorizing about warrant. (shrink)

One strategy for dealing with apparent cases of knowledge from falsehood is to deny that the knowledge actually is from a falsehood. Those endorsing such a move have suggested that cases of knowledge from falsehood are instead cases of knowledge despite falsehood. We here provide a dilemma for those wanting to reject the possibility of knowledge from falsehood. The dilemma is explained in part by examining recent attempts to deny that knowledge can be inferentially derived from falsehood.

One of the many problems that would have t o be solved by a satisfactory theory of empirical knowledge, perhaps the most central is a general structural problem which I shall call the epistemic regress problem: the problem of how to avoid an in- finite and presumably vicious regress of justification in ones account of the justifica- tion of empirical beliefs. Foundationalist theories of empirical knowledge, as we shall see further below, attempt t o avoid the regress by locating a (...) class of empirical beliefs whose justification does not depend on that of other empirical beliefs. Extemalist theories, the topic of the present paper, represent one species of foundationalism. (shrink)

The generality problem is widely considered to be a devastating objection to reliabilist theories of justification. My goal in this paper is to argue that a version of the generality problem applies to all plausible theories of justification. Assume that any plausible theory must allow for the possibility of reflective justification—S's belief, B, is justified on the basis of S's knowledge that she arrived at B as a result of a highly (but not perfectly) reliable way of reasoning, R. The (...) generality problem applies to all cases of reflective justification: Given that is the product of a process-token that is an instance of indefinitely many belief-forming process-types (or BFPTs), why is the reliability of R, rather than the reliability of one of the indefinitely many other BFPTs, relevant to B's justificatory status? This form of the generality problem is restricted because it applies only to cases of reflective justification. But unless it is solved, the generality problem haunts all plausible theories of justification, not just reliabilist ones. (shrink)

That in Gettier's alleged counterexamples to the traditional analysis of knowledge as justified true belief the belief condition is satisfied has rarely been questioned. Yet there is reason to doubt that a rational person would come to believe what Gettier's protagonists are said to believe in the way they are said to have come to believe it. If they would not, the examples are not counter-examples to the traditional analysis. I go on to discuss a number of examples inspired by (...) Gettier's and argue that they, too, fail to be counter-examples either for reasons similar to those I have urged or because it is not clear that their subject does not know. (shrink)

This paper provides a novel argument for granting memory the status of a generative source of justification and knowledge. Memory can produce justified output beliefs and knowledge on the basis of unjustified input beliefs alone. The key to understanding how memory can generate justification and knowledge, memory generativism, is to bear in mind that memory frequently omits part of the stored information. The proposed argument depends on a broadly reliabilist approach to justification.

The global method safety account of knowledge states that an agent’s true belief that p is safe and qualifies as knowledge if and only if it is formed by method M, such that her beliefs in p and her beliefs in relevantly similar propositions formed by M in all nearby worlds are true. This paper argues that global method safety is too restrictive. First, the agent may not know relevantly similar propositions via M because the belief that p is the (...) only possible outcome of M. Second, there are cases where there is a fine-grained belief that is unsafe and a relevantly similar coarse-grained belief that is safe and where both beliefs are based on the same method M. Third, the reliability of conditional reasoning, a basic belief-forming method, seems to be sensitive to fine-grained contents, as suggested by the wide variation in success rates for thematic versions of the Wason selection task. (shrink)

This paper discusses two versions of reliabilism: modal and probabilistic reliabilism. Modal reliabilism faces the problem of the missing closeness metric for possible worlds while probalistic reliabilism faces the problem of the relevant reference class. Despite the severity of these problems, reliabilism is still very plausible (also for independent reasons). I propose to stick with reliabilism, propose a contextualist (or, alternatively, harmlessly relativist) solution to the above problems and suggest that probabilistic reliabilism has the advantage over modal reliabilism.

We often think or say that someone was wrong about something but almost right about it or close to the truth. This can mean more than one thing. Here, I propose an analysis of the idea of being epistemically close to the truth. This idea plays an important role in our practice of epistemic evaluation and therefore deserves some detailed attention. I start with an exposition of the idea of getting things right by looking at the main forms of reliabilism (...) about true belief and belief acquisition. The focus on reliabilism is justified because everyone is a reliabilist in a basic sense. Section 2 develops a notion of closeness to the truth in two steps. Section 3 mentions some ways in which this notion is useful, one having to do with the Gettier problem. (shrink)

Certain puzzling cases have been discussed in the literature recently which appear to support the thought that knowledge can be obtained by way of deduction from a falsehood; moreover, these cases put pressure, prima facie, on the thesis of counter closure for knowledge. We argue that the cases do not involve knowledge from falsehood; despite appearances, the false beliefs in the cases in question are causally, and therefore epistemologically, incidental, and knowledge is achieved despite falsehood. We also show that the (...) principle of counter closure, and the concomitant denial of knowledge from falsehood, is well motivated by considerations in epistemological theory--in particular, by the view that knowledge is first in the epistemological order of things. (shrink)

Testimony is the mainstay of human communication and essential for the spread of knowledge. But testimony may also spread error. Under what conditions does it yield knowledge in the person addressed? Must the recipient trust the attester? And does the attester have to know what is affirmed? A related question is what is required for the recipient to be justified in believing testimony. Is testimony-based justification acquired in the same way as testimony-based knowledge? This paper addresses these and other questions. (...) It offers a theory of the role of testimony in producing knowledge and justification, a sketch of a conception of knowledge that supports this theory, a brief account of how trust of others can be squared with critical habits of mind, and an outline of some important standards for intellectual responsibility in giving and receiving testimony. (shrink)

David Lewis (1941-2001) was Class of 1943 University Professor of Philosophy at Princeton University. His contributions spanned philosophical logic, philosophy of language, philosophy of mind, philosophy of science, metaphysics, and epistemology. In On the Plurality of Worlds, he defended his challenging metaphysical position, "modal realism." He was also the author of the books Convention, Counterfactuals, Parts of Classes, and several volumes of collected papers.

In this paper I will offer a comprehensive defense of the safety account of knowledge against counterexamples that have been recently put forward. In Sect. 2, I will discuss different versions of safety, arguing that a specific variant of method-relativized safety is the most plausible. I will then use this specific version of safety to respond to counterexamples in the recent literature. In Sect. 3, I will address alleged examples of safe beliefs that still constitute Gettier cases. In Sect. 4, (...) I will discuss alleged examples of unsafe knowledge. In Sect. 5, I will address alleged cases of safe belief that do not constitute knowledge for non-Gettier reasons. My overall goal is to show that there are no successful counterexamples to robust anti-luck epistemology and to highlight some major presuppositions of my reply. (shrink)

According to some philosophers who accept a propositional conception of evidence, someone's evidence includes a proposition only if it is true. I argue against this thesis by appealing to the possibility of knowledge from falsehood.

Reliabilist accounts of knowledge are widely seen as having the resources for blocking sceptical arguments, since these arguments appear to rely on assumptions about the nature of knowledge that are rendered illegitimate by reliabilist accounts. The goal of this book is to assess the main arguments against the possibility of knowledge, and its conclusions challenge this consensus. The book articulates and defends a theory of knowledge that belongs firmly in the truth-tracking tradition, and argues that although the theory has the (...) resources for blocking the main standard lines of sceptical reasoning, there is a sceptical argument against which the theory offers no defence, as it doesn’t rely on any assumptions that the theory would render illegitimate. The book ends with the suggestion that the problem might have a metaphysical solution—that although the sceptical argument may make no illegitimate epistemological assumptions, it does rest on a questionable account of the nature of cognition. (shrink)

Knowledge and its Limits presents a systematic new conception of knowledge as a kind of mental stage sensitive to the knower's environment. It makes a major contribution to the debate between externalist and internalist philosophies of mind, and breaks radically with the epistemological tradition of analyzing knowledge in terms of true belief. The theory casts new light on such philosophical problems as scepticism, evidence, probability and assertion, realism and anti-realism, and the limits of what can be known. The arguments are (...) illustrated by rigorous models based on epistemic logic and probability theory. The result is a new way of doing epistemology and a notable contribution to the philosophy of mind. (shrink)

Edmund Gettier is Professor Emeritus at the University of Massachusetts, Amherst. This short piece, published in 1963, seemed to many decisively to refute an otherwise attractive analysis of knowledge. It stimulated a renewed effort, still ongoing, to clarify exactly what knowledge comprises.

I propose and defend the conjecture that what explains why Gettiered subjects fail to know is the fact that their justified true belief depends essentially on unknown propositions. The conjecture follows from the plausible principle about inference in general according to which one knows the conclusion of one’s inference only if one knows all the premises it involves essentially.

The chapter begins with some general remarks about closure and counter-closure, and is followed with a discussion of the following: I (a) review some (alleged) counterexamples to counter-closure, I then continue by (b) discussing a popular strategy for responding to such counterexamples to counter-closure, and finally I (c) pose a dilemma for this popular strategy. Once I have discussed these three points I conclude the chapter by proposing that we reject counter-closure, but at the same time that we accept an (...) epistemological package that includes closure and another intuitively plausible principle with regards to the psychology and epistemology of deductive inference. (shrink)

According to the received view in epistemology, inferential knowledge from non-knowledge is impossible – that is, in order for a subject to know the conclusion of their inference, they must know the essential premises from which that conclusion is drawn. In this book, Federico Luzzi critically examines this view, arguing that it is less plausible than intuition suggests and that it can be abandoned without substantial cost. In a discussion that ranges across inference, testimony and memory he analyses the full (...) range of challenges to the view, connecting them to epistemological cases that support those challenges. He then proposes a defeater-based framework which allows the phenomenon of knowledge from non-knowledge across these three epistemic areas to be better understood. His book will be of interest to a wide range of readers in epistemology. (shrink)

_Conjectures and Refutations_ is one of Karl Popper's most wide-ranging and popular works, notable not only for its acute insight into the way scientific knowledge grows, but also for applying those insights to politics and to history. It provides one of the clearest and most accessible statements of the fundamental idea that guided his work: not only our knowledge, but our aims and our standards, grow through an unending process of trial and error.

The way in which knowledge progresses, and especially our scientific knowledge, is by unjustified anticipations, by guesses, by tentative solutions to our problems, by conjectures. These conjectures are controlled by criticism: that is, by attempted refutations, which include severely critical tests. They may survive these tests; but they can never be positively justified: they can neither be established as certainly true nor even as 'probable'. Criticism of our conjectures is of decisive importance: by bringing out our mistakes it makes us (...) understand the difficulties of the problems which we try to solve. This is how we become better acquainted with our problem, and able to propose more mature solutions: the very refutation of a theory - that is, of a tentative solution to our problem - is always a step forward that takes us nearer the truth. And this is how we can learn from our mistakes. As we learn from our mistakes our knowledge grows, even though we may never know - that is, know for certain. Since our knowledge can grow, there can be no reason here for despair of reason. And since we can never know for certain, the can be no authority here for any claim to authority, for conceit over our knowledge, or for smugness. The essays and lectures of which this book is composed apply this thesis to many topics, ranging from problems of the philosophy and history of the physical and social sciences to historical and political problems. (shrink)

Stephen Grimm finds me inclined to bifurcate epistemic assessment into higher and lower orders while showing awareness of this only in recent writings. Two untoward consequences allegedly follow: (a) my rejection of Virtue Reliabilism, and (b) my knowledge-based account of the value attaching to our knowledge on the higher level. By contrast, Grimm considers Virtue Reliabilism a perfectly adequate account of knowledge, while the higher epistemic state he believes to be, rather, understanding, which he takes to be quite distinct from (...) knowledge. Once knowledge and understanding are seen to be distinct, finally, this will help us to avoid the two untoward consequences. I am grateful for these interesting points, and would like to respond briefly in what follows. (shrink)

What do you get when you cross a fallacy with a good argument? A fugu, that is, a valid argument that tempts you to reach its conclusion invalidly. You have yielded to the temptation more than you realize. If you are a teacher, you may have served many fugus. They arise systematically through several mechanisms. Fugus are interesting intermediate cases that shed light on the following issues: bare evidentialism, false pleasure, philosophy of education, and the ethics of argument. Normally, a (...) fugu will not yield knowledge from known premises. But if the reasoning is only slightly fallacious, they do yield knowledge. These mild fugus show that we can gain knowledge by invalid reasoning. This is a conservative resource for historians. They want to credit discoveries to Euclid rather than those who made minor corrections to his proofs, such as David Hilbert. We also benefit from this practice of grandfathering in old standards of knowledge attribution. For we can compete spiritedly for priority. We do not need to worry that credit will instead go to future scholars who will make the minor amendments needed to raise present proofs to a future standard of demonstration. (shrink)

A growing number of authors defend putative examples of knowledge from falsehood (KFF), inferential knowledge based in a critical or essential way on false premises, and they argue that KFF has important implications for many areas of epistemology (whether evidence can be false, the Gettier debate, defeasibility theories of knowledge, etc.). I argue, however, that there is no KFF, because in any supposed example either the falsehood does not contribute to the knowledge or the subject lacks knowledge. In particular, I (...) show that if the subject actually has knowledge in putative KFF cases, then there is always a veridical evidential path meeting the basing conditions that accounts for her knowledge; if there is no such path, then the subject is in a type of Gettier case. All the recent arguments that rely on KFF are therefore based on a mistake. (shrink)