John Turri

Appeals to ordinary thought and talk are frequent in philosophy, perhaps nowhere more than in contemporary epistemology. When an epistemological theory implies serious error in “commonsense” or “folk” epistemology, it is counted as a cost of the view. Similarly, when an epistemological theory respects or vindicates deep patterns in commonsense epistemology, it is viewed as a benefit of the view. Philosophers typically rely on introspection and anecdotal social observation to support their characterizations of commonsense epistemology. But recent experimental research shows that philosophers employing these methods often seriously mischaracterize commonsense. Based on these findings, I propose a fundamental change to standard practice in the field. Whether the fundamental goal of epistemology is descriptive or prescriptive, experimentation is an integral part of the project.

“Gettier cases” have played a major role in Anglo-American analytic epistemology over the past fifty years. Philosophers have grouped a bewildering array of examples under the heading “Gettier case.” Philosophers claim that these cases are obvious counterexamples to the “traditional” analysis of knowledge as justified true belief, and they treat correctly classifying the cases as a criterion for judging proposed theories of knowledge. Cognitive scientists recently began testing whether philosophers are right about these cases. It turns out that philosophers were partly right and partly wrong. Some “Gettier cases” are obvious examples of ignorance, but others are obvious examples of knowledge. It also turns out that much research in this area of philosophy is marred by experimenter bias, invented historical claims, dysfunctional categorization of examples, and mischaracterization by philosophers of their own intuitive judgments about particular cases. Despite these shortcomings, lessons learned from studying “Gettier cases” are leading to important insights about knowledge and knowledge attributions, which are central components of social cognition.

I introduce an account of when a rule normatively sustains a practice. My basic proposal is that a rule normatively sustains a practice when the value achieved by following the rule explains why agents continue following that rule, thus establishing and sustaining a pattern of activity. I apply this model to practices of belief management and identifies a substantive normative connection between knowledge and belief. More specifically, I proposes one special way that knowledge might set the normative standard for belief: knowing is essentially the unique way of normatively sustaining cognition and, thereby, inquiry. In this respect, my proposal can be seen as one way of elaborating a “knowledge-first” normative theory.

A standard view in social science and philosophy is that a lie is a dishonest assertion: to lie is to assert something that you think is false in order to deceive your audience. We report four behavioral experiments designed to evaluate some aspects of this view. Participants read short scenarios and judged several features of interest, including whether an agent lied. We found evidence that ordinary lie attributions can be influenced by aspects of audience uptake, are based on judging that the agent made an assertion (assertion attributions), and, at least in some contexts, are not based on attributions of deceptive intent. The finding on assertion attributions is predicted by the standard view, but the finding on intent attributions is not. These results help to further clarify the ordinary concept of lying and shed light on the psychological processes involved in ordinary lie attributions and related judgments.

This paper addresses a fundamental question in folk metaphysics: how do we ordinarily view human agency? According to the transcendence account, we view human agency as standing outside of the causal order and imbued with exceptional powers. According to a naturalistic account, we view human agency as subject to the same physical laws as other objects and completely open to scientific investigation. According to exceptionalist naturalism, the truth lies somewhere in between: we view human agency as fitting broadly within the causal order while still being exceptional in important respects. In this paper, I report seven experiments designed to decide between these three competing theories. Across a variety of contexts and types of action, participants agreed that human agents can resist outcomes described as inevitable, guaranteed, and causally determined. Participants viewed non-human animal agents similarly, whereas they viewed computers, robots, and simple inanimate objects differently. At the same time, participants judged that human actions are caused by many things, including psychological, neurological, and social events. Overall, in folk metaphysics, human and non-human animals are viewed as exceptional parts of the natural world.

Many philosophers hypothesize that our concept of personal identity is partly constituted by the one-person-one-place rule, which states that a person can only be in one place at a time. This hypothesis has been assumed by the most influential contemporary work on personal identity. In this paper, we report a series of studies testing whether the hypothesis is true. In these studies, people consistently judged that the same person existed in two different places at the same time. This result undermines some widely held philosophical assumptions, supports others, and fits well with recent discoveries on identity judgments about inanimate objects and non-human animals.

Virtue epistemologists define knowledge as true belief produced by intellectual virtue. In this paper, I review how this definition fails in three important ways. First, it fails as an account of the ordinary knowledge concept, because neither belief nor reliability is essential to knowledge ordinarily understood. Second, it fails as an account of the knowledge relation itself, insofar as that relation is operationalized in the scientific study of cognition. Third, it serves no prescriptive purpose identified up till now. An alternative theory, abilism, provides a superior account of knowledge as it is ordinarily and scientifically understood. According to abilism, knowledge is an accurate representation produced by cognitive ability.

I review recent work from armchair and cross-cultural epistemology on whether humans possess a knowledge concept as part of a universal “folk epistemology.” The work from armchair epistemology fails because it mischaracterizes ordinary knowledge judgments. The work from cross-cultural epistemology provides some defeasible evidence for a universal folk epistemology. I argue that recent findings from comparative psychology establish that humans possess a species-typical knowledge concept. More specifically, recent work shows that knowledge attributions are a central part of primate social cognition, used to predict others’ behavior and guide decision-making. The core primate knowledge concept is that of truth detection (across different sensory modalities) and retention (through memory) and may also include rudimentary forms of indirect truth discovery through inference. In virtue of their evolutionary heritage, humans inherited the primate social-cognitive system and thus share this core knowledge concept.

This chapter reviews some faults of the theoretical literature and findings from the experimental literature on “Gettier” cases. Some “Gettier” cases are so poorly constructed that they are unsuitable for serious study. Some longstanding assumptions about how people tend to judge “Gettier” cases are false. Some “Gettier” cases are judged similarly to paradigmatic ignorance, whereas others are judged similarly to paradigmatic knowledge, rendering it a theoretically useless category. Experimental procedures can affect how people judge “Gettier” cases. Some important central tendencies in judging “Gettier” cases appear to be robust against demographic variation in biological sex, age, language, and culture, although there could be some interesting differences related to culture and personality traits. Some remaining questions regarding Gettier’s cases, “Gettier” cases, and “the Gettier problem” concern the psychology and sociology of contemporary anglophone theoretical epistemology. Some remaining questions regarding the empirical study of knowledge judgments concern mechanisms underlying observed behavioral patterns.

I review recent empirical findings on knowledge attributions in lottery cases and report a new experiment that advances our understanding of the topic. The main novel finding is that people deny knowledge in lottery cases because of an underlying qualitative difference in how they process probabilistic information. “Outside” information is generic and pertains to a base rate within a population. “Inside” information is specific and pertains to a particular item’s propensity. When an agent receives information that 99% of all lottery tickets lose (outside information), people judge that she does not know that her ticket will lose. By contrast, when an agent receives information that her specific ticket is 99% likely to lose (inside information), people judge that she knows that her ticket will lose. Despite this difference in knowledge judgments, people rate the likelihood of her ticket losing the exact same in both cases (i.e. 99%). The results shed light on other factors affecting knowledge judgments in lottery cases, including formulaic expression and participants’ own estimation of whether it is true that the ticket will lose. The results also undermine previous hypotheses offered for knowledge denial in lottery cases, including the hypotheses that people deny knowledge because they either deny justification or acknowledge a chance for error.

Philosophers are divided on whether it is possible to intend believed-impossible outcomes. Several thought experiments in the action theory literature suggest that this is conceptually possible, though they have not been tested in ordinary social cognition. We conducted three experiments to determine whether, on the ordinary view, it is conceptually possible to intend believed-impossible outcomes. Our findings indicate that participants firmly countenance the possibility of intending believed-impossible outcomes, suggesting that it is conceptually possible to intend to do something that one believes is impossible.

I accomplish two things in this paper. I explain the motivation for including experimental research in philosophical projects on epistemic reasons and the basing relation. And I present the first experimental contributions to these projects. The results from two experiments advance our understanding of the ordinary concepts of reasons and basing and set the stage for further research on the topics. More specifically, the results support a causal theory of the basing relation, according to which reasons are causes, and a dualist theory of epistemic reasons, according to which reasons include both psychological and non-psychological items.

A standard view in philosophy is that knowledge entails justification. Yet recent research suggests otherwise. We argue that this admirable and striking research suffers from an important limitation: participants were asked about knowledge but not justification. Thus it is possible that people attributed knowledge partly because they thought the belief was justified. Perhaps though, if given the opportunity, people would deny justification while still attributing knowledge. It is also possible that earlier findings were due to perspective taking. This paper reports further research that directly addresses these questions. Our findings support the hypothesis that knowledge entails justification on the ordinary view.

According to a consensus view in philosophy, “deciding” and “intending” are synonymous expressions. Researchers have recently challenged this view with the discovery of a counterexample in which ordinary speakers attribute deciding without intending. The aim of this paper is to investigate the strengths and limits of this discovery. The result of this investigation revealed that the evidence challenging the consensus view is strong. We replicate the initial finding against consensus and extend it by utilizing several new measures, materials, and procedures. Together this evidence strongly suggests that “deciding” is not synonymous with “intending” in ordinary language and that the consensus view should be rejected.

[From SEP]: Contemporary virtue epistemology (hereafter ‘VE’) is a diverse collection of approaches to epistemology. At least two central tendencies are discernible among the approaches. First, they view epistemology as a normative discipline. Second, they view intellectual agents and communities as the primary focus of epistemic evaluation, with a focus on the intellectual virtues and vices embodied in and expressed by these agents and communities. This entry introduces many of the most important results of the contemporary VE research program. These include novel attempts to resolve longstanding disputes, solve perennial problems, grapple with novel challenges, and expand epistemology’s horizons. In the process, it reveals the diversity within VE. Beyond sharing the two unifying commitments mentioned above, its practitioners diverge over the nature of intellectual virtues, which questions to ask, and which methods to use. It will be helpful to note some terminology before proceeding. First, we use ‘cognitive’, ‘epistemic’ and ‘intellectual’ synonymously. Second, we often use ‘normative’ broadly to include not only norms and rules, but also duties and values. Finally, ‘practitioners’ names contemporary virtue epistemologists.

Contemporary virtue epistemology (hereafter ‘VE’) is a diverse collection of approaches to epistemology. At least two central tendencies are discernible among the approaches. First, they view epistemology as a normative discipline. Second, they view intellectual agents and communities as the primary focus of epistemic evaluation, with a focus on the intellectual virtues and vices embodied in and expressed by these agents and communities. This entry introduces many of the most important results of the contemporary VE research program. These include novel attempts to resolve longstanding disputes, solve perennial problems, grapple with novel challenges, and expand epistemology’s horizons. In the process, it reveals the diversity within VE. Beyond sharing the two unifying commitments mentioned above, its practitioners diverge over the nature of intellectual virtues, which questions to ask, and which methods to use. It will be helpful to note some terminology before proceeding. First, we use ‘cognitive’, ‘epistemic’ and ‘intellectual’ synonymously. Second, we often use ‘normative’ broadly to include not only norms and rules, but also duties and values. Finally, ‘practitioners’ names contemporary virtue epistemologists.

Approximation involves representing things in ways that might be close to the truth but are nevertheless false. Given the widespread reliance on approximations in science and everyday life, here we ask whether it is conceptually possible for false approximations to qualify as knowledge. According to the factivity account, it is impossible to know false approximations, because knowledge requires truth. According to the representational adequacy account, it is possible to know false approximations, if they are close enough to the truth for present purposes. In this paper, we adopt an experimental methodology to begin testing these two theories. When an agent provides a false and practically inadequate answer, both theories predict that people will deny knowledge. But the theories disagree about an agent who provides a false but practically adequate answer: the factivity hypothesis again predicts knowledge denial, whereas the representational adequacy hypothesis predicts knowledge attribution. Across two experiments, our principal finding was that people tended to attribute knowledge for false but practically adequate answers, which supports the representational adequacy account. We propose an interpretation of existing findings that preserves a conceptual link between knowledge and truth. According to this proposal, truth is not necessary for knowledge, but it is a feature of prototypical knowledge.

From antiquity through the twentieth century, philosophers have hypothesized that, intuitively, it is harder to know negations than to know affirmations. This paper provides direct evidence for that hypothesis. In a series of studies, I found that people naturally view negations as harder to know than affirmations. Participants read simple scenarios and made judgments about truth, probability, belief, and knowledge. Participants were more likely to attribute knowledge of an outcome when framed affirmatively than when framed negatively. Participants did this even though the affirmative and negative framings were logically equivalent. The asymmetry was unique to knowledge attributions: it did not occur when participants rated truth, probability, or belief. These findings show new consequences of negation on people’s judgments and reasoning and can inform philosophical theorizing about the ordinary concept of knowledge.

This paper advances our understanding of the norms of assertion in two ways. First, I evaluate recent studies claiming to discredit an important earlier finding which supports the hypothesis that assertion has a factive norm. In particular, I evaluate whether it was due to stimuli mentioning that a speaker’s evidence was fallible. Second, I evaluate the hypothesis that assertion has a truth-insensitive standard of justification. In particular, I evaluate the claim that switching an assertion from true to false, while holding all else objectively constant, is irrelevant to attributions of justification. Two pre-registered experiments provide decisive evidence against each claim. In the first experiment, switching from mentioning to not mentioning fallibility made no difference to assertability attributions, thereby disproving the criticism concerning fallibility. By contrast, switching an assertion from true to false decreased the rate of assertability attribution from over 90% to less than 20%, thereby replicating and vindicating the original finding supporting a factive norm. In the second experiment, switching an assertion from true to false decreased the rate of justification attribution from over 80 to 10%, thereby undermining the hypothesis that assertion’s standard of justification is truth-insensitive. The second experiment also demonstrates that perspective-taking influences attributions of justification, and it provides initial evidence that the standard of justification for assertion is stricter than the standard for belief.

It is widely accepted in epistemology that knowledge is factive, meaning that only truths can be known. We argue that this theory creates a skeptical challenge: because many of our beliefs are only approximately true, and therefore false, they do not count as knowledge. We consider several responses to this challenge and propose a new one. We propose easing the truth requirement on knowledge to allow approximately true, practically adequate representations to count as knowledge. In addition to addressing the skeptical challenge, this view also coheres with several previous theoretical proposals in epistemology.

Radical skepticism is the view that we know nothing, or at least next to nothing. Nearly no one actually believes that skepticism is true. Yet it has remained a serious topic of discussion for millennia and it looms large in popular culture. What explains its persistent and widespread appeal? How does the skeptic get us to doubt what we ordinarily take ourselves to know? I present evidence from two experiments that classic skeptical arguments gain potency from an interaction between two factors. First, people evaluate inferential belief more harshly than perceptual belief. Second, people evaluate inferential belief more harshly when its content is negative (i.e. that something is not the case) than when it’s positive (i.e. that something is the case). It just so happens that potent skeptical arguments tend to focus our attention on negative inferential beliefs, and we are especially prone to doubt that such beliefs count as knowledge. That is, our cognitive evaluations are biased against this specific combination of source and content. The skeptic sows seeds of doubt by exploiting this feature of our psychology.

If someone unintentionally breaks the rules, do they break the rules? In the abstract, the answer is obviously “yes.” But, surprisingly, when considering specific examples of unintentional, blameless rule-breaking, approximately half of people judge that no rule was broken. This effect, known as excuse validation, has previously been observed in American adults. Outstanding questions concern what causes excuse validation, and whether it is peculiar to American moral psychology or cross-culturally robust. The present paper studies the phenomenon cross-culturally, focusing on Korean and American adults, and proposes a new explanation of why people engage in excuse validation, in terms of competing forces in human norm-psychology. The principal findings are that Americans and Koreans engaged in excuse validation at similar levels, and older adults were more likely to engage in excuse validation.

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.

This chapter enhances and extends a powerful and promising research program, performance-based epistemology, which stands at the crossroads of many important currents that one can identify in contemporary epistemology, including the value problem, epistemic normativity, virtue epistemology, and the nature of knowledge. Performance-based epistemology offers at least three outstanding benefits: it explains the distinctive value that knowledge has, it places epistemic evaluation into a familiar and ubiquitous pattern of evaluation, and it solves the Gettier problem. But extant versions of performance-based epistemology have been the object of serious criticism. This chapter shows how to meet the objections without sacrificing the aforementioned benefits.

Researchers have debated whether there is a relationship between a statement’s truth-value and whether it counts as a lie. One view is that a statement being objectively false is essential to whether it counts as a lie; the opposing view is that a statement’s objective truth-value is inessential to whether it counts as a lie. We report five behavioral experiments that use a novel range of behavioral measures to address this issue. In each case, we found evidence of a relationship. A statement’s truth-value affects how quickly people judge whether it is a lie. When people consider the matter carefully and are told that they might need to justify their answer, they are more likely to categorize a statement as a lie when it is false than when it is true. When given options that inhibit perspective-taking, people tend to not categorize deceptively motivated statements as lies when they are true, even though they still categorize them as lies when they are false. Categorizing a speaker as “lying” leads people to strongly infer that the speaker’s statement is false. People are more likely to spontaneously categorize a statement as a lie when it is false than when it is true. We discuss four different interpretations of relevant findings to date. At present, the best supported interpretation might be that the ordinary lying concept is a prototype concept, with falsity being a centrally important element of the prototypical lie.

If moral responsibilities prescribe how agents ought to behave, are there also intellectual responsibilities prescribing what agents ought to believe? Many theorists have argued that there cannot be intellectual responsibilities because they would require the ability to control whether one believes, whereas it is impossible to control whether one believes. This argument appeals to an “ought implies can” principle for intellectual responsibilities. The present paper tests for the presence of intellectual responsibilities in social cognition. Four experiments show that intellectual responsibilities are attributed to believe things and that these responsibilities can exceed what agents are able to believe. Furthermore, the results show that agents are sometimes considered responsible for failing to form true beliefs on the basis of good evidence, and that this effect does not depend on the seriousness of the consequences for failing to form a belief. These findings clarify when and how responsibilities for belief are attributed, falsify a conceptual entailment between ability and responsibility in the intellectual domain, and emphasize the importance of objective truth in intellectual evaluations.

We conducted five experiments that reveal some main contours of the folk epistemology of lotteries. The folk tend to think that you don't know that your lottery ticket lost, based on the long odds ("statistical cases"); by contrast, the folk tend to think that you do know that your lottery ticket lost, based on a news report ("testimonial cases"). We evaluate three previous explanations for why people deny knowledge in statistical cases: the justification account, the chance account, and the statistical account. None of them seems to work. We then propose a new explanation of our own, the formulaic account, according to which some people deny knowledge in statistical cases due to formulaic expression.

Nearly all success is due to some mix of ability and luck. But some successes we attribute to the agent’s ability, whereas others we attribute to luck. To better understand the criteria distinguishing credit from luck, we conducted a series of four studies on knowledge attributions. Knowledge is an achievement that involves reaching the truth. But many factors affecting the truth are beyond our control and reaching the truth is often partly due to luck. Which sorts of luck are compatible with knowledge? We find that knowledge attributions are highly sensitive to lucky events that change the explanation for why a belief is true. By contrast, knowledge attributions are surprisingly insensitive to lucky events that threaten but ultimately fail to change the explanation for why a belief is true. These results shed light on our concept of knowledge, help explain apparent inconsistencies in prior work on knowledge attributions, and constitute progress toward a general understanding of the relation between success and luck.