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.

In the philosophical literature on mental states, the paradigmatic examples of mental states are beliefs, desires, intentions, and phenomenal states such as being in pain. The corresponding list in the psychological literature on mental state attribution includes one further member: the state of knowledge. This article examines the reasons why developmental, comparative and social psychologists have classified knowledge as a mental state, while most recent philosophers--with the notable exception of Timothy Williamson-- have not. The disagreement is traced back to a (...) difference in how each side understands the relationship between the concepts of knowledge and belief, concepts which are understood in both disciplines to be closely linked. Psychologists and philosophers other than Williamson have generally have disagreed about which of the pair is prior and which is derivative. The rival claims of priority are examined both in the light of philosophical arguments by Williamson and others, and in the light of empirical work on mental state attribution. (shrink)

Six-month-old infants discriminate between large sets of objects on the basis of numerosity when other extraneous variables are controlled, provided that the sets to be discriminated differ by a large ratio (8 vs. 16 but not 8 vs. 12). The capacities to represent approximate numerosity found in adult animals and humans evidently develop in human infants prior to language and symbolic counting.

An impressive case has been built for the hypothesis that knowledge is the norm of assertion, otherwise known as the knowledge account of assertion. According to the knowledge account, you should assert something only if you know that it’s true. A wealth of observational data supports the knowledge account, and some recent empirical results lend further, indirect support. But the knowledge account has not yet been tested directly. This paper fills that gap by reporting the results of such a test. (...) The knowledge account passes with flying colors. (shrink)

Five experiments demonstrate the central role of knowledge attributions in social evaluations. In Experiments 1–3, we manipulated whether an agent believes, is certain of, or knows a true proposition and asked people to rate whether the agent should perform a variety of actions. We found that knowledge, more so than belief or certainty, leads people to judge that the agent should act. In Experiments 4–5, we investigated whether attributions of knowledge or certainty can explain an important finding on how people (...) act based on statistical evidence, known as “the Wells effect”. We found that knowledge attributions, but not certainty attributions, mediate this effect on decision making. 2018 APA, all rights reserved). (shrink)

Recent work has shown that knowledge attributions affect how people think others should behave, more so than belief attributions do. This paper reports two experiments providing evidence that knowledge attributions also affect behavioral predictions more strongly than belief attributions do, and knowledge attributions facilitate faster behavioral predictions than belief attributions do. Thus, knowledge attributions play multiple critical roles in social cognition, guiding judgments about how people should and will behave.

According to factive accounts of the norm of belief and decision-making, you should not believe or base decisions on a falsehood. Even when the evidence misleadingly suggests that a false proposition is true, you should not believe it or base decisions on it. Critics claim that factive accounts are counterintuitive and badly mischaracterize our ordinary practice of evaluating beliefs and decisions. This paper reports four experiments that rigorously test the critic’s accusations and the viability of factive accounts. The results undermine (...) the accusations and provide the best evidence yet of factive norms of belief and decision-making. The results also help discriminate between two leading candidates for a factive norm: truth and knowledge. Knowledge is the superior candidate. (shrink)

Centuries ago, Descartes and Locke initiated a foundational debate in epistemology over the relationship between knowledge, on the one hand, and practical factors, on the other. Descartes claimed that knowledge and practice are fundamentally separate. Locke claimed that knowledge and practice are fundamentally united. After a period of dormancy, their disagreement has reignited on the contemporary scene. Latter-day Lockeans claim that knowledge itself is essentially connected to, and perhaps even constituted by, practical factors such as how much is at stake, (...) how important the situation is, or how one should act. Latter-day Cartesians claim, by contrast, that knowledge is entirely constituted by truth-related factors such as truth, belief, and evidence. Each side has supported its case with claims about patterns in ordinary behavior and knowledge judgments. Lockeans argue that these patterns are best explained by positing a fundamental and direct link between knowledge and practical factors. Cartesians argue that the patterns can be equally well explained by positing an indirect link, entirely mediated by the traditional factors of truth, belief, and evidence, thereby rendering the Lockean hypothesis unnecessary. We argue that Cartesians are right about some practical factors, in particular stakes and how important a situation is, which have, at best, a modest indirect relationship to knowledge. However, Lockeans are right about actionability: whether a person should pursue a course of action is unquestionably very powerfully and directly connected to knowledge. (shrink)

Researchers recently demonstrated a strong direct relationship between judgments about what a person knows and judgments about how a person should act. But it remains unknown whether actionability judgments cause knowledge judgments, or knowledge judgments cause actionability judgments. This paper uses causal modeling to help answer this question. Across two experiments, we found evidence that actionability judgments cause knowledge judgments.

This target article presents a theory of human cultural learning. Cultural learning is identified with those instances of social learning in which intersubjectivity or perspective-taking plays a vital role, both in the original learning process and in the resulting cognitive product. Cultural learning manifests itself in three forms during human ontogeny: imitative learning, instructed learning, and collaborative learning – in that order. Evidence is provided that this progression arises from the developmental ordering of the underlying social-cognitive concepts and processes involved. (...) Imitative learning relies on a concept of intentional agent and involves simple perspective-taking. Instructed learning relies on a concept of mental agent and involves alternating/coordinated perspective-taking (intersubjectivity). Collaborative learning relies on a concept of reflective agent and involves integrated perspective-taking (reflective intersubjectivity). A comparison of normal children, autistic children and wild and enculturated chimpanzees provides further evidence for these correlations between social cognition and cultural learning. Cultural learning is a uniquely human form of social learning that allows for a fidelity of transmission of behaviors and information among conspecifics not possible in other forms of social learning, thereby providing the psychological basis for cultural evolution. (shrink)

Intuitions play an important role in contemporary epistemology. Over the last decade, however, experimental philosophers have published a number of studies suggesting that epistemic intuitions may vary in ways that challenge the widespread reliance on intuitions in epistemology. In a recent paper, Jennifer Nagel offers a pair of arguments aimed at showing that epistemic intuitions do not, in fact, vary in problematic ways. One of these arguments relies on a number of claims defended by appeal to the psychological literature on (...) intuitive judgment and on mental state attribution (also known as “theory of mind”, “mindreading” and “folk psychology”). I call this the "theoretical argument". The other argument relies on recent experimental work carried out by Nagel and her collaborators. It is my contention that in setting out her theoretical argument, Nagel offers an account of the relevant scientific literature that is, in crucial respects, flawed and misleading. My main goal in this paper is to rectify these errors and to make it clear that, once this is done, Nagel’s theoretical argument collapses. Since Nagel’s experimental work has not yet been published, and available details are very sketchy, I do not discuss this work in detail. However, in the final section of the paper I offer some critical observations about Nagel’s strategy for dealing with empirical data that does not support her view – both other people’s and her own. (shrink)

How do people decide which claims should be considered mere beliefs and which count as knowledge? Although little is known about how people attribute knowledge to others, philosophical debate about the nature of knowledge may provide a starting point. Traditionally, a belief that is both true and justified was thought to constitute knowledge. However, philosophers now agree that this account is inadequate, due largely to a class of counterexamples (termed ‘‘Gettier cases’’) in which a person’s justified belief is true, but (...) only due to luck. We report four experiments examining the effect of truth, justification, and ‘‘Gettiering’’ on people’s knowledge attributions. These experiments show that: (1) people attribute knowledge to others only when their beliefs are both true and justified; (2) in contrast to contemporary philosophers, people also attribute knowledge to others in Gettier situations; and (3) knowledge is not attributed in one class of Gettier cases, but only because the agent’s belief is based on ‘‘apparent’’ evidence. These findings suggest that the lay concept of knowledge is roughly consistent with the traditional account of knowledge as justified true belief, and also point to a major difference between the epistemic intuitions of laypeople and those of philosophers. (shrink)

What modal relation must a fact bear to a belief in order for this belief to constitute knowledge of that fact? Externalists have proposed various answers, including some that combine externalism with contextualism. We shall find that various forms of externalism share a modal conception of “sensitivity” open to serious objections. Fortunately, the undeniable intuitive attractiveness of this conception can be explained through an easily confused but far preferable notion of “safety.” The denouement of our reflections, finally, will be to (...) show how replacing sensitivity with safety makes it possible to defend plain Moorean common sense against the spurious advantages over it claimed by skeptical, tracking, relevant-alternative, and contextualist accounts. (shrink)

Eye movements during false-belief tasks can reveal an individual's capacity to implicitly monitor others' mental states (theory of mind - ToM). It has been suggested, based on the results of a single-trial-experiment, that this ability is impaired in those with a high-functioning autism spectrum disorder (ASD), despite neurotypical-like performance on explicit ToM measures. However, given there are known attention differences and visual hypersensitivities in ASD it is important to establish whether such impairments are evident over time. In addition, investigating implicit (...) ToM using a repeated trial approach allows an assessment of whether learning processes can reduce the ASD impairment in this ability, as is the case with explicit ToM. Here we investigated the temporal profile of implicit ToM in individuals with ASD and a control group. Despite similar performance on explicit ToM measures, ASD-diagnosed individuals showed no evidence of implicit false-belief tracking even over a one-hour period and many trials, whereas control participants did. These findings demonstrate that the systems involved in implicit and explicit ToM are distinct and hint that impaired implicit false-belief tracking may play an important role in ASD. Further, they indicate that learning processes do not alleviate this impairment across the presentation of multiple trials. (shrink)

An individual has a theory of mind if he imputes mental states to himself and others. A system of inferences of this kind is properly viewed as a theory because such states are not directly observable, and the system can be used to make predictions about the behavior of others. As to the mental states the chimpanzee may infer, consider those inferred by our own species, for example, purpose or intention, as well as knowledge, belief, thinking, doubt, guessing, pretending, liking, (...) and so forth. To determine whether or not the chimpanzee infers states of this kind, we showed an adult chimpanzee a series of videotaped scenes of a human actor struggling with a variety of problems. Some problems were simple, involving inaccessible food as in the original Kohler problems; others were more complex, involving an actor unable to extricate himself from a locked cage, shivering because of a malfunctioning heater, or unable to play a phonograph because it was unplugged. With each videotape the chimpanzee was given several photographs, one a solution to the problem, such as a stick for the inaccessible bananas, a key for the locked up actor, a lit wick for the malfunctioning heater. The chimpanzee's consistent choice of the correct photographs can be understood by assuming that the animal recognized the videotape as representing a problem, understood the actor's purpose, and chose alternatives compatible with that purpose. (shrink)

Research on theory of mind has primarily focused on demonstrating and understanding the ability to represent others' non‐factive mental states, for example, others' beliefs in the false‐belief task. This requirement confuses the ability to represent a particular kind of non‐factive content (e.g., a false belief) with the more general capacity to represent others' understanding of the world even when it differs from one's own. We provide a way of correcting this. We first offer a simple and theoretically motivated account on (...) which tracking another agent's understanding of the world and keeping that representation separate from one's own are the essential features of a capacity for theory of mind. We then show how these criteria can be operationalized in a new experimental paradigm: the “diverse‐knowledge task.”. (shrink)

We provide a cognitive analysis of how children represent belief using mental files. We explain why children who pass the false belief test are not aware of the intensionality of belief. Fifty-one 3½- to 7-year old children were familiarized with a dual object, e.g., a ball that rattles and is described as a rattle. They observed how a puppet agent witnessed the ball being put into box 1. In the agent’s absence the ball was taken from box 1, the child (...) was reminded of it being a rattle, and emphasising its being a rattle it was put back into box 1. Then the agent returned, the object was hidden in the experimenter’s hands and removed from box 1, described as a ‘‘rattle,” and transferred to box 2. Children who passed false belief had no problem saying where the puppet would look for the ball. However, in a different condition in which the agent was also shown that the ball was a rattle they erroneously said that the agent would look for the ball in box 1, ignoring the agent’s knowledge of the identity of rattle and ball. Their problems cease with their mastery of second-order beliefs. Problems also vanish when the ball is described not as a rattle but as a thing that rattles. We describe how our theory can account for these data as well as all other relevant data in the literature. (shrink)

Most epistemologists hold that knowledge entails belief. However, proponents of this claim rarely offer a positive argument in support of it. Rather, they tend to treat the view as obvious and assert that there are no convincing counterexamples. We find this strategy to be problematic. We do not find the standard view obvious, and moreover, we think there are cases in which it is intuitively plausible that a subject knows some proposition P without—or at least without determinately—believing that P. Accordingly, (...) we present five plausible examples of knowledge without (determinate) belief, and we present empirical evidence suggesting that our intuitions about these scenarios are not atypical. (shrink)

The standard view in epistemology is that propositional knowledge entails belief. Positive arguments are seldom given for this entailment thesis, however; instead, its truth is typically assumed. Against the entailment thesis, Myers-Schulz and Schwitzgebel (Noûs, forthcoming) report that a non-trivial percentage of people think that there can be propositional knowledge without belief. In this paper, we add further fuel to the fire, presenting the results of four new studies. Based on our results, we argue that the entailment thesis does not (...) deserve the default status that it is typically granted. We conclude by considering the alternative account of knowledge that Myers-Schulz and Schwitzgebel propose to explain their results, arguing that it does not explain ours. In its place we offer a different explanation of both sets of findings—the conviction account, according to which belief, but not knowledge, requires mental assent. (shrink)

In this article, we present evidence that in four different cultural groups that speak quite different languages there are cases of justified true beliefs that are not judged to be cases of knowledge. We hypothesize that this intuitive judgment, which we call “the Gettier intuition,” may be a reflection of an underlying innate and universal core folk epistemology, and we highlight the philosophical significance of its universality.

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.

W. Labov's & T. Labov's findings concerning their child grammar acquisition ("Learning the Syntax of Questions" in Recent Advances in the Psychology of Language, Campbell, R. & Smith, P. Eds, New York: Plenum Press, 1978) are interpreted in terms of different semantics of why & other wh-questions. Z. Dubiel.

Factive mental states, such as knowing or being aware, can only link an agent to the truth; by contrast, nonfactive states, such as believing or thinking, can link an agent to either truths or falsehoods. Researchers of mental state attribution often draw a sharp line between the capacity to attribute accurate states of mind and the capacity to attribute inaccurate or “reality-incongruent” states of mind, such as false belief. This article argues that the contrast that really matters for mental state (...) attribution does not divide accurate from inaccurate states, but factive from nonfactive ones. (shrink)

Children's utterances from late infancy to 3 years of age were examined to infer their conception of knowledge. In Study 1, the utterances of two English-speaking children were analysed and in Study 2, the utterances of a Mandarin-speaking child were analysed – in both studies, for their use of the verb know. Both studies confirmed that know and not know were used to affirm, query or deny knowledge, especially concerning an ongoing topic of conversation. References to a third party were (...) rare. By implication, 2-year-olds have a conception of knowledge that underpins their exchange of information in conversation. Implications for the child's developing theory of mind are discussed. (shrink)