Virtually everything we know depends in some way or other on the testimony of others—what we eat, how things work, where we go, even who we are. We do not, after all, perceive firsthand the preparation of the ingredients in many of our meals, or the construction of the devices we use to get around the world, or the layout of our planet, or our own births and familial histories. These are all things we are told. Indeed, subtracting from our lives the information that we possess via testimony leaves them barely recognizable. Scientific discoveries, battles won and lost, geographical developments, customs and traditions of distant lands—all of these facts would be completely lost to us. It is, therefore, no surprise that the importance of testimony, both epistemological and practical, is nearly universally accepted.
Less consensus, however, is found when questions about the nature and extent of our dependence on the word of others arise. Is our justified reliance on testimony fundamentally basic, for instance, or is it ultimately reducible to perception, memory, and reason? Is trust, or some related interpersonal feature of our social interaction with one another, essential to the acquisition of beliefs that are testimonially justified? Is testimonial knowledge necessarily acquired through transmission from speaker to hearer? Can testimony generate epistemic features in its own right? These are the questions that will be taken up in this essay and, as will become clear, their answers have far-reaching consequences for how we understand our place in the social world.
The central focus in the epistemology of testimony is not on the nature of testimony itself, but instead on how justified belief or knowledge is acquired on the basis of what other people tell us. Because of this, those interested in the epistemology of testimony often embrace a very broad notion of what it is to testify, one that leaves the distinction between reliable and unreliable (or otherwise epistemically good and bad) testimony for epistemology to delineate.1 So, for instance, Elizabeth Fricker holds that the domain of testimony that is of epistemological interest is that of “tellings generally” with “no restrictions either on subject matter, or on the speaker’s epistemic relation to it.”2 Similarly, Robert Audi claims that in accounting for testimonial knowledge and justification, we must understand testimony as “people’s telling us things.”3 And Ernest Sosa embraces “a broad sense of testimony that counts posthumous publications as examples . . . [and] requires only that it be a statement of someone’s thoughts or beliefs, which they might direct to the world at large and to no one in particular.”4
Despite the virtues of these broad conceptions of what it is to testify, however, there is reason to think that, as stated, they are too broad. In particular, there is a difference between entirely noninformational expressions of thought and testimony. For instance, suppose that you and I are walking down the street and I say, “Ah, it is indeed a lovely day.” Suppose further that such a statement, though it expresses my thought that it is indeed a lovely day, is neither offered nor taken as conveying information; it is simply a conversational filler, comparable to a sigh of contentedness.5 Or suppose that as my young daughter glides across the ice on her new skates for the first time, I shout, “You can do it!” While my assertion here is surely an expression of my thought that Catherine has the capacity to ice skate, its function in this context is merely to encourage her to accomplish a difficult task, similar to clapping or cheering. There is no intention on my part to convey information, nor is Catherine apt to acquire information, from my words of encouragement. In both cases, it is doubtful that these statements should qualify as testimony, despite the fact that they are “tellings” or expressions of thought. Otherwise put, the concept of testimony is intimately connected with the notion of conveying information, and thus those statements that function as mere conversational fillers and cheers should fail to qualify as instances of testimony. A more precise account of the nature of testimony, then, should be formulated as a speaker’s making an act of communication—which includes statements, nods, pointing, and so on—that is intended to convey the information that p or is taken as conveying the information that p.6
Moreover, clearly not everything we learn from the testimony of others qualifies as testimonially based. For instance, suppose that I say that ten people have spoken in this room today and you, having counted the previous nine, come to know that ten people have spoken in this room today.7 Here, my statement may certainly be causally relevant with respect to your forming this belief, but your knowledge is based on your having heard and counted the speakers in the room today, thereby rendering it perceptual in nature. Or suppose that I sing “I have a soprano voice” in a soprano voice and you come to know this entirely on the basis of hearing my soprano voice.8 Again, the resulting knowledge is perceptual in nature since it is based on your hearing my soprano voice rather than on what I testified to. What is of import for distinctively testimonial justification or knowledge is that a hearer form a given belief on the basis of the content of a speaker’s testimony. This precludes cases such as those above—where a belief is formed entirely on the basis of features about the speaker’s testimony—from qualifying as instances of testimonial justification or knowledge.
There are also intermediate cases in which a hearer has relevant background information and uses it to derive knowledge from the statement of a speaker. For example, suppose that you know from past experience that I report that there is no coffee in the carafe only when there is some. Now when I report to you that there is no coffee in the carafe, you may supplement my testimony with your background information and hence derive knowledge that there is coffee in the carafe. Because the epistemic status of beliefs formed in these types of cases relies so heavily on memory and inference, the resulting justification and knowledge are only partially testimonially based. Hence, such beliefs typically fall outside the scope of theories purporting to capture only those beliefs that are entirely based on testimony.
One of the central questions in the epistemology of testimony is how, exactly, hearers acquire justified beliefs from the testimony of speakers. Answers to this question have traditionally fallen into one of two camps: nonreductionism or reductionism. According to nonreductionists—whose historical roots are typically traced to the work of Thomas Reid—testimony is a basic source of justification, on an epistemic par with sense perception, memory, inference, and the like. Given this, nonreductionists maintain that, so long as there are no relevant undefeated defeaters, hearers can be justified in accepting what they are told merely on the basis of the testimony of speakers.9 So, for instance, Tyler Burge writes that “[a] person is entitled to accept as true something that is presented as true and that is intelligible to him, unless there are stronger reasons not to do so.” Similarly, Matthew Weiner argues that “[w]e are justified in accepting anything that we are told unless there is positive evidence against doing so.” And Robert Audi claims that “gaining testimonially grounded knowledge normally requires only having no reason for doubt about the credibility of the attester.” In all of these passages, we find endorsements of nonreductionism.10
There are two central kinds of defeaters that are typically taken to be relevant to the nonreductionist’s view. First, there are what we might call psychological defeaters. A psychological defeater is a doubt or belief that is had by S, and indicates that S’s belief that p is either false or unreliably formed or sustained. Defeaters in this sense function by virtue of being had by S, regardless of their truth-value or epistemic status.11 Second, there are what we might call normative defeaters. A normative defeater is a doubt or belief that S ought to have, and indicates that S’s belief that p is either false or unreliably formed or sustained. Defeaters in this sense function by virtue of being doubts or beliefs that S should have (whether or not S does have them) given the presence of certain available evidence.12 The underlying thought here is that certain kinds of doubts and beliefs contribute epistemically unacceptable irrationality to doxastic systems and, accordingly, justification can be defeated or undermined by their presence.
Moreover, a defeater may itself be either defeated or undefeated. Suppose, for instance, that Harold believes that there is a bobcat in his backyard because he saw it there this morning, but Rosemary tells him, and he thereby comes to believe, that the animal is instead a lynx. Now, the justification Harold had for believing that there was a bobcat in his backyard has been defeated by the belief he acquires on the basis of Rosemary’s testimony. But since psychological defeaters can themselves be beliefs, they, too, are candidates for defeat. For instance, suppose that Harold consults a North American wildlife book and discovers that the white tip of the animal’s tail confirms that it was indeed a bobcat, thereby providing him with a defeater-defeater for his original belief that there was a bobcat in his backyard. And, as should be suspected, defeater-defeaters can also be defeated by further doubts and beliefs, which, in turn, can be defeated by further doubts and beliefs, and so on. Similar considerations involving reasons, rather than doubts and beliefs, apply in the case of normative defeaters. When one has a defeater for one’s belief that p that is not itself defeated, one has what is called an undefeated defeater for one’s belief that p. It is the presence of undefeated defeaters, not merely of defeaters, that is incompatible with testimonial justification.
In contrast to nonreductionism, reductionists—whose historical roots are standardly traced to the work of David Hume—maintain that, in addition to the absence of undefeated defeaters, hearers must also possess nontestimonally based positive reasons in order to be justified in accepting the testimony of speakers. These reasons are typically the result of induction: for instance, hearers observe a general conformity between reports and the corresponding facts and, with the assistance of memory and reason, inductively infer that certain speakers, contexts, or types of reports are reliable sources of information. In this way, the justification of testimony is reduced to the justification for sense perception, memory, and inductive inference.13
There are two different versions of reductionism. According to global reductionism, the justification of testimony as a source of belief reduces to the justification of sense perception, memory, and inductive inference. Thus, in order to be justified in accepting the testimony of speakers, hearers must possess nontestimonially based positive reasons for believing that testimony is generally reliable. According to local reductionism, which is the more widely accepted of the two versions, the justification of each instance of testimony reduces to the justification of instances of sense perception, memory, and inductive inference. So, in order to be justified in accepting the testimony of speakers, hearers must have nontestimonially based positive reasons for accepting the particular report in question. For instance, Paul Faulkner writes:
Given that a speaker’s intentions in communicating need not be informative and given the relevance of these intentions to the acquisition of testimonial knowledge . . . [i]t is doxastically irresponsible to accept testimony without some background belief in the testimony’s credibility or truth. In the case of perception and memory, rational acceptance requires only the absence of defeating background beliefs. In the case of testimony, rational acceptance requires the presence of supporting background beliefs.
This demand of responsibility may be expressed as a criterion of justification. An audience is justified in forming a testimonial belief if and only if he is justified in accepting the speaker’s testimony.14
Similarly, Elizabeth Fricker maintains, “In claiming that a hearer is required to assess a speaker for trustworthiness, I [mean] . . . that the hearer should be discriminating in her attitude to the speaker, in that she should be continually evaluating him for trustworthiness throughout their exchange, in the light of the evidence, or cues, available to her. This will be partly a matter of her being disposed to deploy background knowledge which is relevant, partly a matter of her monitoring the speaker for any tell-tale signs revealing likely untrustworthiness.”15
Both nonreductionism and reductionism have been subject to various objections, objections that opponents use to motivate their own preferred views. The central problem raised against nonreductionism is that it is said to sanction gullibility, epistemic irrationality, and intellectual irresponsibility.16 For given that, on such a view, hearers can acquire testimonially justified beliefs in the complete absence of any relevant positive reasons, randomly selected speakers, arbitrarily chosen postings on the Internet, and unidentified telemarketers can be trusted, so long as there is no negative evidence against such sources. Yet surely, the opponent of nonreductionism urges, accepting testimony in these kinds of cases is a paradigm of gullibility, epistemic irrationality, and irresponsibility.
Against reductionism, it is frequently argued that young children clearly acquire a great deal of knowledge from their parents and teachers and yet it is said to be doubtful that they possess—or even could possess—nontestimonially based positive reasons for accepting much of what they are told.17 For instance, an eighteen-month-old baby may come to know that the stove is hot from the testimony of her mother, but it is unclear whether she has the cognitive sophistication to have reasons for believing her mother to be a reliable source of information, let alone for believing that testimony is generally reliable. Given this, reductionists—of both the global and the local stripes—may be hard pressed to explain how such young subjects could acquire all of the testimonial knowledge they at least seem to possess.
Objections are also raised that are specific to each kind of reductionism. Against the global version, two main problems arise. The first is that in order to have nontestimonially based positive reasons that testimony is generally reliable, one would have to be exposed not only to a wide-ranging sample of reports but also to a wide-ranging sample of the corresponding facts. But both are said to be problematic. With respect to the reports, most of us have been exposed only to a very limited range of reports from speakers in our native language in a handful of communities in our native country. This limited sample of reports provides only a fraction of what would be required to legitimately conclude that testimony is generally reliable. With respect to the corresponding facts, a similar problem arises: the observational base of ordinary epistemic agents is simply far too small to allow the requisite induction about the reliability of testimony. As C. A. J. Coady says:
it seems absurd to suggest that, individually, we have done anything like the amount of field-work that [reductionism] requires. . . . [M]any of us have never seen a baby born, nor have most of us examined the circulation of the blood nor the actual geography of the world nor any fair sample of the laws of the land, nor have we made the observations that lie behind our knowledge that the lights in the sky are heavenly bodies immensely distant nor a vast number of other observations that [reductionism] would seem to require.18
Moreover, with many reports, such as those involving complex scientific, economic, or mathematical theories, most of us simply lack the conceptual machinery needed to properly check the reports against the facts. Global reductionism, then, is said to ultimately lead to skepticism about testimonial knowledge, at least for most epistemic agents.
A second objection raised against global reductionism is that it is questionable whether there even is an epistemically significant fact of the matter regarding the general reliability of testimony. To see this, consider, for instance, the following epistemically heterogeneous list of types of reports, all of which are subsumed under “testimony in general”: reports about the time of day, what one had for breakfast, the achievements of one’s children, whether one’s loved one looks attractive in a certain outfit, the character of one’s political opponents, one’s age and weight, one’s criminal record, and so on. Some of these types of reports may be generally highly reliable (e.g., about the time of day and what one had for breakfast), generally highly unreliable (e.g., about the achievements of one’s children, the looks of one’s loved ones, and the character of one’s political opponents), and generally very epistemically mixed, depending on the speaker (e.g., about one’s age, weight, and criminal record). Because of this epistemic heterogeneity, it is doubtful not only whether “testimony” picks out an epistemically interesting or unified kind but also whether it even makes sense to talk about testimony being a generally reliable source. As Elizabeth Fricker says, “looking for generalisations about the reliability or otherwise of testimony . . . as a homogenous whole, will not be an enlightening project. Illuminating generalisations, if there are any, will be about particular types of testimony, differentiated according to subject matter, or type of speaker, or both. . . . [W]hen it comes to the probability of accuracy of speakers’ assertions, and what sorts of factors warrant a hearer in trusting a speaker, testimony is not a unitary category.”19
Against the local version of reductionism, it is argued that most ordinary cognitive agents do not seem to have enough information to possess relevant positive reasons in all the cases where testimonial knowledge appears present. For instance, it is argued that most cognitive agents frequently acquire testimonial knowledge from speakers about whom they know very little.20 For instance, on arriving in Chicago for the first time, I may receive accurate directions to Navy Pier from the first passerby I see. Most agree that such a transaction can result in my acquiring testimonial knowledge of Navy Pier’s whereabouts, despite the fact that my positive reasons for accepting the directions in question—if indeed I possess any—are scanty at best.
The direction some recent work on testimony has taken is to avoid the problems afflicting nonreductionism and reductionism by developing qualified or hybrid versions of either of these views.21 For instance, in an effort to avoid the charges of gullibility and epistemic irresponsibility, some nonreductionists emphasize that hearers must be “epistemically entitled” to rely on the testimony of speakers or that they need to “monitor” incoming reports, even though such requirements do not quite amount to the full-blown need for nontestimonially based positive reasons embraced by reductionists.22 And some reductionists, trying to account for the testimonial knowledge of both young children and those hearers who possess very little information about their relevant speakers, argue that positive reasons are not needed during either the “developmental phase” of a person’s life—which is when one is acquiring concepts and learning the language, relying in large part on one’s parents and teachers to guide the formation of one’s belief system; or when hearers are confronted with “mundane testimony”: testimony about, for instance, a speaker’s name, what she had for breakfast, the time of day, and so on.23 On this view of reductionism, then, while positive reasons remain a condition of testimonial justification, such a requirement applies only to hearers in the “mature phase” of life who are encountering “nonmundane testimony.” Such qualified or hybrid views of both nonreductionism and reductionism often encounter either variations of the very same problems that led to their development, or altogether new objections.24
Arguably, a more promising strategy for solving the problems afflicting nonreductionism and reductionism should, first, include a necessary condition requiring nontestimonially grounded positive reasons for testimonial justification. This avoids the charges of gullibility, epistemic irrationality, and intellectual irresponsibility facing the nonreductionist’s view. Second, the demands of such a condition should be weakened so that merely some positive reasons, even about the type of speaker, or the kind of report, or the sort of context of utterance, are required. This avoids the objections facing the reductionist’s position that young children cannot satisfy such a requirement and that beliefs formed on the basis of the testimony of those about whom we know very little cannot be justified. Third, additional conditions should be added for a complete account of testimonial justification, such as the need for the reliability of the speaker’s statement. This frees the positive reasons requirement from shouldering all of the justificatory burden for testimonial beliefs, thereby enabling the weakening of its content discussed above.25
An alternative family of views has been growing in popularity in recent work in the epistemology of testimony, one that provides a radically different answer to the question of how testimonial beliefs are justified. Though there are some points of disagreement among some of the members of this family, they are united in their commitment to at least three central theses. First, and perhaps most important, the interpersonal relationship between the two parties in a testimonial exchange should be a central focus of the epistemology of testimony. Second, and closely related, certain features of this interpersonal relationship—such as the speaker offering her assurance to the hearer that her testimony is true, or the speaker inviting the hearer to trust her—are (at least sometimes) actually responsible for conferring epistemic value on the testimonial beliefs acquired. Third, the epistemic justification provided by these features of a testimonial exchange is nonevidential in nature. For ease of discussion, I shall call the general conception of testimony characterized by these theses the interpersonal view of testimony (IVT).26
One of the central motivations for the IVT is a perceived failure of existing views of testimony—particularly those that regard a speaker’s testimony that p as merely evidence for a hearer to believe that p—to adequately account for the import of the interpersonal relationship between the speaker and the hearer in a testimonial exchange. For instance, in discussing such evidential views of testimonial justification, Edward Hinchman says, “[w]hen you have evidence of a speaker’s reliability you don’t need to trust her: you can treat her speech act as a mere assertion and believe what she says on the basis of the evidence you have of its truth. You can ignore the fact that she’s addressing you, inviting you. You can treat her as a truth-gauge.”27 In a similar spirit, Richard Moran maintains that “if we are inclined to believe what the speaker says, but then learn that he is not, in fact, presenting his utterance as an assertion whose truth he stands behind, then what remains are just words, not a reason to believe anything . . . the utterance as [a] phenomenon, loses the epistemic import we thought it had.”28 According to proponents of the IVT, then, a significant aspect of true communication is missing when a speaker is treated as a mere truth gauge, offering nothing more than words.
In contrast, proponents of the IVT argue that speakers should be regarded as agents who enter into interpersonal relationships with their hearers. For instance, according to Moran’s version of the IVT—the assurance view—a speaker’s testimony that p is understood as the speaker giving her assurance that p is true. Since assurance can be given only when it is freely presented as such, Moran claims that a speaker freely assumes responsibility for the truth of p when she asserts that p, thereby providing the hearer with an additional reason to believe that p, different in kind from anything given by evidence alone. In a similar spirit, Hinchman argues:
How can I entitle you to believe what I tell you? One way is by influencing the evidence available to you, perhaps by making an assertion or otherwise manifesting a belief, which still makes you epistemically responsible for the belief I want you to form. Another is by inviting you to trust me, thereby taking part of that responsibility onto my own shoulders. These two ways of giving an epistemic entitlement work very differently. When a speaker tells her hearer that p . . . she acts on an intention to give him an entitlement to believe that p that derives not from evidence of the truth of “p” but from his mere understanding of the act she thereby perform . . . unlike acts of mere assertion, acts of telling give epistemic warrant directly.29
Now, whereas Moran claims that the assurance of truth that the speaker gives to the hearer is the nonevidential feature of their interpersonal relationship that confers epistemic value on testimonial beliefs, Hinchman’s trust view maintains that this feature is the speaker’s invitation to the hearer to trust her.
There is, however, a central problem afflicting the IVT, which can be cast in terms of a dilemma. The first horn is that if the view in question is genuinely interpersonal, it is epistemologically impotent. To see this, notice that a natural question to ask the proponents of the IVT is what the precise connection is between a speaker’s giving a hearer assurance of the truth of her utterance or a speaker’s inviting a hearer to trust her and the truth itself. Otherwise put, what is the epistemic value of such interpersonal features? By way of answering this question, Moran says, “the speaker, in presenting his utterance as an assertion, one with the force of telling the audience something, presents himself as accountable for the truth of what he says, and in doing so he offers a kind of guarantee for this truth.”30 But even if a speaker explicitly offers her hearer a guarantee of the truth of her assertion, what does this actually have to do with the truth itself? For instance, consider Beatrice, a radically unreliable believer who consistently offers assertions to her hearers that she sincerely believes to be true but that are wholly disconnected from the truth. Now since Beatrice presents herself as accountable for the truth of what she says, Moran claims that the hearer in question is thereby provided with a guarantee of the truth of what Beatrice says. But what does this so-called guarantee amount to? Nearly every time Beatrice offers an assertion to a hearer, it turns out to be false. In this way, she is what we might call a reliably unreliable testifier. Moreover, notice that the point brought out by this case is not merely that a speaker can give her assurance that p is true but be wrong on a particular occasion; rather, the point is that a speaker can repeatedly give her assurance that various propositions are true and yet consistently offer utterances that fail to be reliably connected with the truth in any way. A “guarantee” of truth that nearly always turns out to be false, however, is a far cry from anything resembling a genuine guarantee. Thus, as it stands, the assurance view, though genuinely interpersonal, is epistemologically impotent. For, in the absence of distinctively epistemic conditions placed on the testimonial exchange, a speaker can give assurance and thereby a justified belief to a hearer even when she shouldn’t be able to (because, e.g., she is a radically unreliable testifier). If the assurance view is going to be a genuine contender in the epistemology of testimony, however, it simply cannot float free from all that is epistemic.
Aware of the sort of problem afflicting the assurance view, Hinchman adds the following crucial amendment to his trust view:
Trust is a source of epistemic warrant just when it is epistemically reasonable. Trust is epistemically reasonable when the thing trusted is worthy of the trust—as long as there is no evidence available that it is untrustworthy. Assuming satisfaction of this negative evidential condition . . . when an epistemic faculty is trustworthy by serving as a reliable guide to the truth, it makes available an entitlement to believe what it tells you whose basis lies simply in the fact that you trust it.31
In order for the acceptance of an invitation to trust to confer epistemic justification directly on a testimonial belief acquired, then, the following two conditions must be satisfied:
1. the speaker’s testimony must serve as a reliable guide to the truth, and
2. the hearer cannot have any relevant undefeated defeaters (i.e., “evidence available” that the speaker trusted “is untrustworthy”) for accepting the invitation to trust the speaker.
Now, as should be clear, the addition of these two conditions puts the trust view of testimony on the epistemological map. In particular, by virtue of placing epistemic conditions on both the speaker and the hearer in a testimonial exchange, the trust view avoids the debilitating objection that it is simply impotent for the epistemology of testimony.
However, here is where the second horn of the dilemma afflicting the IVT emerges: if the IVT is not epistemologically impotent, then neither is it genuinely interpersonal. In other words, while it is true that the addition of conditions (1) and (2) renders the trust view a genuine contender in the epistemology of testimony, it does so at the cost of making trust itself epistemically superfluous. To see this, consider the following case. Abraham and Belinda, thinking they are alone in their office building, are having a discussion about the private lives of their coworkers. During the course of their conversation, Abraham tells Belinda that their boss is having an affair with the latest intern hired by the company, Iris. Unbeknownst to them, Edgar has been eavesdropping on their conversation, and so he, like Belinda, comes to believe solely on the basis of Abraham’s testimony—which is in fact both true and epistemically impeccable—that their boss is having an affair with Iris. Moreover, Belinda and Edgar not only have the same relevant background information about both Abraham’s reliability as a testifier and the proffered testimony, they also are properly functioning recipients of testimony who possess no relevant undefeated defeaters. Now, according to all versions of the IVT, Belinda’s testimonial belief in the case of the eavesdropper possesses epistemic value that Edgar’s does not. For while Abraham offered Belinda his assurance that his testimony is true and invited Belinda to trust him, neither is true of the relationship between Abraham and eavesdropping Edgar. Because of this, the epistemic value of Edgar’s belief about the affair between the boss and intern Iris is inferior to, or at least different from, that of Belinda’s belief with the same content.
But if Belinda and Edgar are equally properly functioning as recipients of testimony, have the same relevant background information, both about Abraham as a testifier and about the proposition to which he is testifying, and form their beliefs about the boss and Iris solely on the basis of Abraham’s testimony, then what could distinguish their beliefs epistemically? According to Hinchman’s view, the central difference between these two cases is that Belinda’s, but not Edgar’s, justification for believing the boss and Iris are having an affair is acquired simply by recognizing Abraham’s intention to give her an entitlement to hold this belief. That these two justifications are epistemologically different is apparently evidenced by the purported fact that, were Belinda and Edgar both to refuse to treat Abraham’s telling as a source of epistemic justification, Abraham “is entitled to feel slighted” by Belinda’s refusal but not by Edgar’s. For Abraham has “tendered an invitation to [Belinda] to trust [him] and explicitly been rebuffed,” whereas Edgar was tendered no such invitation and thus cannot slight Abraham in this way.32 The thought underlying these remarks is that there are certain expectations that come along with invitations and, accordingly, certain attitudes that follow from their being rejected or accepted.
There are, however, at least two central problems with this response. First, it is not at all clear that the difference cited by Hinchman between situations involving the invited and the noninvited in fact hold. For instance, suppose that after the scenario envisaged in this case, Abraham and Edgar are later talking at a dinner party and Edgar confesses both that he eavesdropped on Abraham’s conversation with Belinda and that he has no relevant information about the boss and Iris other than what Abraham reported to Belinda. Suppose further that Abraham then asks, “So what do you think about the boss and Iris?” and Edgar responds, “Oh, I don’t believe that the boss and Iris are having an affair.” Wouldn’t Abraham be entitled to feel slighted by Edgar’s refusal to believe what he reported, even if he did not issue a specific invitation to trust him? Indeed, it is not at all clear that Abraham would, or should, feel more slighted by Belinda’s refusal to believe him than by Edgar’s, for both are revealing in their refusals their belief that Abraham is somehow untrustworthy, either in general or with respect to the topic at hand. It may even be the case that Abraham is entitled to feel more slighted by Edgar’s refusal to believe him than by Belinda’s if we suppose, for instance, that Abraham regards Edgar, but not Belinda, as a friend.
The second, and more important, problem with the above response is that, even if Hinchman is correct about the purported differences between the situations involving the invited and the noninvited, being entitled to the reactions in question lacks any epistemological significance and hence fails to establish that there is an epistemologically relevant difference between justification from telling and justification from mere asserting. In particular, Abraham’s being entitled to feel slighted should Belinda, but not Edgar, refuse his invitation to trust and Belinda’s, but not Edgar’s, being entitled to feel resentment should Abraham prove untrustworthy do not bear in any way on the truth-conduciveness or epistemic rationality of the testimonial beliefs in question. For notice: Abraham’s inviting Belinda but not Edgar to trust him does not make it more likely that the testimonial belief in question is true for Belinda but not for Edgar—they are both receiving testimony with the same degree of reliability, the same kind of truth-tracking, the same amount of proper functioning, and so on. Moreover, Belinda and Edgar have the same relevant background information about both Abraham’s reliability as a testifier and the proffered testimony, so it is not more rational for Belinda to form the relevant belief than it is for Edgar. Of course, a situation may be envisaged in which Belinda but not Edgar has had a deep friendship with Abraham since childhood and, because of this, has more reasons to trust Abraham’s testimony. But this doesn’t show that interpersonal features of a relationship can affect the epistemic value of testimonial beliefs; all it shows is that a hearer who possesses more evidence for the trustworthiness of a given speaker can acquire a testimonial belief that is more justified than a hearer who does not—an obvious point, but one that fails to support the IVT.
What these considerations show is that interpersonal features are not capable of adding epistemic value to testimonial beliefs. This is made clear in the eavesdropping case: there does not seem to be anything epistemically significant about the fact that, though Belinda and Edgar both learned about the boss’s affair from Abraham’s testimony, only the former was told this. Indeed, the counterintuitive consequences of the IVT quickly proliferate: if you are addressing a particular room of people at a conference, surely the epistemic value of the belief that I acquire on the basis of your testimony does not differ from those acquired by the audience members merely because I overhear your talk from the hallway. Or if you write a book with the intended audience being Democrats, the fact that a Republican reads it should not, by itself, affect the epistemic status of the testimonial beliefs that are thereby acquired. Interpersonal features, then, do not add any epistemic value to testimonial beliefs that is not already contributed by the truth-conducive grounding in question, thereby rendering such features epistemologically impotent.
Thus, while the addition of conditions (1) and (2) places the trust view on the epistemological map, trust itself turns out to be epistemically superfluous. For the reason it is no longer an utter mystery how justification could be conferred through the acceptance of an invitation to trust is because conditions (1) and (2) do all the epistemic work. When a hearer acquires a justified belief that p from a speaker’s telling her that p, this is explained through both the speaker’s reliability as a testifier with respect to p and the hearer’s rationality as a recipient of the testimony. In providing the epistemic explanation of the hearer’s newly acquired justified belief, then, trust simply drops out of the picture. Once trust becomes epistemically superfluous, however, the trust view ceases to even represent a version of the IVT. For the interpersonal relationship between the two parties in a testimonial exchange is not the central focus of the epistemology of testimony on such a view, nor are features of this interpersonal relationship responsible for conferring epistemic value on the testimonial beliefs acquired—the reliability of the speaker’s testimony and the rationality of the hearer’s acceptance of the testimony are doing all of the epistemic work.
The upshot of these considerations, then, is that there is a general dilemma confronting the proponent of the IVT: either the view of testimony in question is genuinely interpersonal but not epistemological, or it is genuinely epistemological but not interpersonal. Either way, the IVT fails to provide a compelling alternative to existing theories in the epistemology of testimony.
Most views in the current literature on testimony are built around a central thesis, which we may call the transmission view (TV). The basic thought expressed by TV is that a testimonial exchange involves a speaker’s knowledge being transmitted to a hearer.33 There are two dimensions to TV; one is a necessity thesis (TVN) and the other is a sufficiency thesis (TVS). More precisely:
TVN: For every speaker, A, and hearer, B, B knows that p on the basis of A’s testimony that p only if A knows that p.34
TVS: For every speaker, A, and hearer, B, if (1) A knows that p, (2) B comes to believe that p on the basis of the content of A’s testimony that p, and (3) B has no undefeated defeaters for believing that p, then B knows that p.35
Support for this view, particularly for TVN, derives from a purported analogy between testimony and memory. While memory is thought to be capable of only preserving knowledge from one time to another—and cannot therefore generate new knowledge—testimony is said to be capable of only transmitting knowledge from one person to another. So, for instance, just as I cannot know that p on the basis of memory unless I nonmemorially knew that p at an earlier time, the thought underlying this picture of testimonial knowledge is that a hearer cannot know that p on the basis of testimony unless the speaker who provided the testimony herself knows that p. Similarly, just as my knowing that p at an earlier time may be sufficient, in the absence of present undefeated defeaters, for me to memorially know that p now, it is said that a speaker’s knowing that p may also be sufficient, in the absence of undefeated defeaters, for a hearer to know that p on the basis of her testimony.
Recently, however, objections have been raised to both dimensions of TV, thereby calling into question the widely accepted view that transmission lies at the heart of the epistemology of testimony.36 There are two general types of counterexamples that have been raised to TVN. The first type involves speakers who fail to believe, and hence know, a proposition to which they are testifying but nevertheless reliably convey the information in question through their testimony. For instance, suppose that a devout creationist who does not believe in the truth of evolutionary theory nonetheless researches the topic extensively and on this basis constructs extremely reliable lecture notes from which she teaches her third-grade students. In such a case, the teacher seems able to reliably teach to her students that Homo sapiens evolved from Homo erectus, thereby imparting knowledge to her students that she fails to possess herself. The second type of counterexample that has been raised to TVN involves speakers who have an undefeated defeater for believing a proposition to which they are testifying, but nevertheless reliably convey such a proposition through their testimony without transmitting the defeater in question to their hearers. For instance, suppose that a speaker in fact possesses her normal visual powers, but she is the subject of a neurosurgeon’s experiments, and the surgeon falsely tells her that implantations are causing malfunction in her visual cortex. While she is persuaded that her present visual appearances are an entirely unreliable guide to reality and thereby possesses a doxastic defeater for the corresponding beliefs, she continues to place credence in her visual appearances. On the basis of her in fact reliable visual experience, then, she forms the true belief that there is a badger in a nearby field and then later reports this fact to her friend without communicating the neurosurgeon’s testimony to him. In such a case, the speaker reliably conveys the content of her visual experience to her hearer, but not her doxastic defeater, thereby imparting knowledge she does not have herself. Both types of cases, then, show that TVN is false.37
There are also two general types of counterexamples that have been raised to TVS. The first type of case shows that, for reasons having to do specifically with the hearer, a hearer’s belief may fail to be an instance of knowledge even though the hearer has no relevant undefeated defeaters, the speaker from whom it was acquired has the knowledge in question, and the speaker testifies sincerely. For instance, suppose that a hearer is compulsively trusting so that she accepts whatever she is told, regardless of the amount or kind of evidence there is to the contrary. In such a case, the hearer simply is not a properly functioning recipient of testimony. In particular, she is so constituted that the knowledge in question cannot be passed to her, even though she does not possess any relevant defeaters. The second type of counterexample to TVS shows that, for reasons having to do specifically with the speaker, a hearer’s belief may fail to be an instance of knowledge even though the hearer has no relevant undefeated defeaters, the speaker from whom it was acquired has the knowledge in question, and the speaker testifies sincerely. For instance, suppose that a speaker in fact knows that there was a raccoon in the park this morning because she saw one there, but she is such that she would have reported to her hearer that there was such a raccoon even if there hadn’t been one. In such a case, the speaker’s belief is an instance of knowledge, and yet because she is an unreliable testifier, the belief that the hearer forms on the basis of her testimony is not an instance of knowledge. Once again, both types of counterexamples show that TVS is false.38
One of the central conclusions that the above considerations motivate is the replacement of TV with conditions focusing on the statements of speakers rather than on their states of believing or knowing. More precisely, TV may be replaced with the following statement view (SV) of testimony:
SV: For every speaker, A, and hearer, B, B knows that p on the basis of A’s testimony that p only if (1) A’s statement that p is reliable or otherwise truth-conducive, (2) B comes to truly believe that p on the basis of the content of A’s statement that p, and (3) B has no undefeated defeaters for believing that p.39
Further conditions may be needed for a complete view of testimonial knowledge, such as the need for positive reasons embraced by reductionists. But regardless of what is added to SV, such a view avoids the problems afflicting TV. Moreover, because hearers can acquire testimonial knowledge from speakers who do not possess the knowledge in question themselves, SV reveals that testimony is not merely a transmissive epistemic source, as has been traditionally assumed, but can instead generate epistemic features in its own right.
Notes
1 For a narrow view that builds the epistemology of testimony directly into its nature, see Coady (1992). For views of the nature of testimony with other types of restrictions, see Ross (1975) and Graham (1997).
2 Fricker (1995, pp. 396–97).
3 Audi (1997, p. 406).
4 Sosa (1991, p. 219).
5 Of course, the situation would be entirely different if, for instance, I were offering this statement to my blind friend with the intention of conveying information about the weather.
6 For a full development of this view, see Lackey (2006c, 2008).
7 This type of example is found in Sosa (1991).
8 This is a variation of an example found in Audi (1997).
9 Proponents of various versions of nonreductionism include Austin (1979), Welbourne (1979, 1981, 1986, 1994), Evans (1982), Reid (1983), Ross (1986), Hardwig (1985, 1991), Coady (1992, 1994), Burge (1993, 1997), Plantinga (1993), Webb (1993), Dummett (1994), Foley (1994), McDowell (1994), Strawson (1994), Williamson (1996, 2000), Goldman (1999), Schmitt (1999), Insole (2000), Owens (2000, 2006), Rysiew (2002), Weiner (2003), Goldberg (2006), and Sosa (2006). Some phrase their views in terms of knowledge, others in terms of justification or entitlement, still others in terms of warrant. Audi (1997, 1998, 2006) embraces a nonreductionist view of testimonial knowledge, but not of testimonial justification. Stevenson (1993), Millgram (1997), and Graham (2006) defend restricted versions of nonreductionism.
10 Burge (1993, p. 467, emphasis added); Weiner (2003, p. 257); Audi 1998, p. 142, emphasis added).
11 For various views of what I call psychological defeaters see, for example, BonJour (1980, 1985), Nozick (1981), Pollock (1986), Goldman (1986), Plantinga (1993), Lackey (1999, 2006b, 2008), Bergmann (1997, 2004), and Reed (2006).
12 For discussions involving what I call normative defeaters, approached in a number of different ways, see BonJour (1980, 1985), Goldman (1986), Fricker (1987, 1994), Chisholm (1989), Burge (1993, 1997), McDowell (1994), Audi (1997, 1998), Williams (1999), Lackey (1999, 2006b, 2008), BonJour and Sosa (2003), Hawthorne (2004), and Reed (2006). What all these discussions have in common is simply the idea that evidence can defeat knowledge (justification) even when the subject does not form any corresponding doubts or beliefs from the evidence in question.
13 Proponents of different versions of reductionism include Hume (1977), Fricker (1987, 1994, 1995, 2006), Adler (1994, 2002), Lyons (1997), Lipton (1998), and Van Cleve (2006). Lehrer (2006) develops a qualified reductionist/nonreductionist view of testimonial justification.
14 Faulkner (2000, 587–88, first emphasis added).
15 Fricker (1994, pp. 149-50).
16 See, for instance, Fricker (1987, 1994, 1995), Faulkner (2000, 2002), and Lackey (2006a, 2008).
17 See, for instance, Audi (1997). For a response to this objection, see Lackey (2005, 2008).
18 Coady (1992, p. 82).
19 Fricker (1994, p. 139, emphasis added).
20 See, for instance, Webb (1993), Foley (1994), Strawson (1994), and Schmitt (1999). For a response to this objection, see Lackey (2006a, 2008).
21 See, for instance, Fricker (1995, 2006a), Faulkner (2000), Goldberg (2006, 2008), and Lehrer (2006).
22 See Goldberg (2006) and Goldberg (2008), respectively, for these qualifications to a nonreductionist view.
23 See Fricker (1995) for these modifications to reductionism.
24 See, for instance, Insole (2000), Weiner (2003), and Lackey (2008).
25 For a detailed development of this strategy, see Lackey (2008).
26 Proponents of the IVT include Ross (1986), Hinchman (2005), Moran (2006), and Faulkner (2007).
27 Hinchman (2005, p. 580, emphasis added).
28 Moran (2006, p. 283, second emphasis added).
29 Hinchman (2005, pp. 563–64).
30 Moran (2006, p. 283, original emphasis).
31 Hinchman (2005, pp. 578–79, emphasis added).
32 Hinchman (2005, pp. 565–66). It should be noted that Hinchman restricts this claim to cases in which the hearer refuses to accept the speaker’s telling in ways that manifest mistrust in the speaker herself. For instance, a speaker may not be entitled to feel slighted if a hearer refuses to accept her telling about the time of day merely because he doubts the accuracy of her watch (rather than the trustworthiness of her word).
33 For the sake of simplicity, I shall here focus on the TV only in terms of knowledge. However, it should be noted that such a view is widely endorsed with respect to other epistemic properties, such as justification, warrant, entitlement, and so on.
34 Proponents of different versions of TVN include Welbourne (1979, 1981, 1986, 1994), Hardwig (1985, 1991), Ross (1986), Burge (1993, 1997), Plantinga (1993), McDowell (1994), Williamson (1996, 2000), Audi (1997, 1998, 2006), Owens (2000, 2006), Reynolds (2002), Faulkner (2006), and Schmitt (2006).
35 Proponents of different versions of TVS include Austin (1979), Welbourne (1979, 1981, 1986, 1994), Evans (1982), Fricker (1987), Coady (1992), McDowell (1994), Adler (1996, 2006), and Owens (2000, 2006). Burge (1993), Williamson (1996, 2000), and Audi (1997) endorse qualified versions of this thesis.
36 See, for instance, Lackey (1999, 2003, 2006b, 2008), Graham (2000), and Goldberg (2001, 2005).
37 Both types of cases are developed in far more depth and detail in Lackey (1999, 2008). The second sort of case is adapted from one found in Goldman (1986), though it is used by Goldman for quite different purposes.
38 Both types of cases are developed in far more depth and detail in Lackey (2006c, 2008).
39 For a detailed defense of SV, see Lackey (2006b, 2008).
Adler, Jonathan E. (1994) “Testimony, Trust, Knowing.” Journal of Philosophy 91: 264–75.
———. (2002) Belief’s Own Ethics. Cambridge, MA: MIT Press.
Audi, Robert. (1997) “The Place of Testimony in the Fabric of Knowledge and Justification.” American Philosophical Quarterly 34: 405–22.
———. (1998) Epistemology: A Contemporary Introduction to the Theory of Knowledge. London: Routledge.
———. (2006) “Testimony, Credulity, and Veracity.” In Jennifer Lackey and Ernest Sosa (eds.), The Epistemology of Testimony. Oxford: Oxford University Press: 25–49.
Austin, J.L. (1979) “Other Minds.” In Austin, Philosophical Papers, 3rd ed. Oxford: Oxford University Press.
Bergmann, Michael. (1997) “Internalism, Externalism and the No-defeater Condition.” Synthese 110: 399–417.
———. (2004) “Epistemic Circularity: Malignant and Benign.” Philosophy and Phenomenological Research 69: 709–27.
BonJour, Laurence. (1980) “Externalist Theories of Epistemic Justification.” Midwest Studies in Philosophy 5: 53–73.
———. (1985) The Structure of Empirical Knowledge. Cambridge, MA: Harvard University Press.
Burge, Tyler. (1993) “Content Preservation.” Philosophical Review 102: 457–88.
———. (1997) “Interlocution, Perception, and Memory.” Philosophical Studies 86: 21–47.
Chisholm, Roderick M. (1989) Theory of Knowledge. 3rd ed. Englewood Cliffs, N.J.: Prentice-Hall.
Coady, C.A.J. (1992) Testimony: A Philosophical Study. Oxford: Clarendon Press.
———. (1994) “Testimony, Observation and ‘Autonomous Knowledge.’” In Bimal Krishna Matilal and Arindam Chakrabarti (eds.), Knowing from Words. Dordrecht: Kluwer Academic: 225–50.
Dummett, Michael. (1994) “Testimony and Memory.” In Bimal Krishna Matilal and Arindam Chakrabarti (eds.), Knowing from Words. Dordrecht: Kluwer Academic: 251–72.
Evans, Gareth. (1982) The Varieties of Reference. Oxford: Clarendon Press.
Faulkner, Paul. (2000) “The Social Character of Testimonial Knowledge.” Journal of Philosophy 97: 581–601.
———. (2002) “On the Rationality of Our Response to Testimony.” Synthese 131: 353–70.
———. (2006) “On Dreaming and Being Lied To.” Episteme 3: 149–59.
———. (2007) “What Is Wrong with Lying?” Philosophy and Phenomenological Research 75: 535–57.
Foley, Richard. (1994) “Egoism in Epistemology.” In Frederick F. Schmitt (ed.), Socializing Epistemology: The Social Dimensions of Knowledge. Lanham, MD: Rowman and Littlefield: 53–73.
Fricker, Elizabeth. (1987) “The Epistemology of Testimony.” Proceedings of the Aristotelian Society, supp. 61: 57–83.
———. (1994) “Against Gullibility.” In Bimal Krishna Matilal and Arindam Chakrabarti (eds.), Knowing from Words. Dordrecht: Kluwer Academic: 125–61.
———. (1995) “Telling and Trusting: Reductionism and Anti-reductionism in the Epistemology of Testimony.” Mind 104: 393–411.
———. (2006a) “Knowledge from Trust in Testimony Is Second-hand Knowledge.” Philosophy and Phenomenological Research 73: 592–618.
———. (2006b) “Testimony and Epistemic Autonomy.” In Jennifer Lackey and Ernest Sosa (eds.), The Epistemology of Testimony. Oxford: Oxford University Press: 225–50.
Goldberg, Sanford C. (2001) “Testimonially Based Knowledge from False Testimony.” Philosophical Quarterly 51: 512–26.
———. (2005) “Testimonial Knowledge through Unsafe Testimony.” Analysis 65: 302–11.
———. (2006) “Reductionism and the Distinctiveness of Testimonial Knowledge.” In Jennifer Lackey and Ernest Sosa (eds.), The Epistemology of Testimony. Oxford: Oxford University Press: 127–44.
———. (2008) “Testimonial Knowledge in Early Childhood, Revisited.” Philosophy and Phenomenological Research 76: 1–36.
Goldman, Alvin I. (1986) Epistemology and Cognition. Cambridge, MA: Harvard University Press.
———. (1999) Knowledge in a Social World. Oxford: Clarendon Press.
Graham, Peter J. (1997) “What Is Testimony?” Philosophical Quarterly 47: 227–32.
———. (2000) “Conveying Information.” Synthese 123: 365–92.
———. (2006) “Liberal Fundamentalism and Its Rivals.” In Jennifer Lackey and Ernest Sosa (eds.), The Epistemology of Testimony. Oxford: Oxford University Press: 93–115.
Hardwig, John. (1985) “Epistemic Dependence.” Journal of Philosophy 82: 335–49.
———. (1991) “The Role of Trust in Knowledge.” Journal of Philosophy 88: 693–708.
Hawthorne, John. (2004) Knowledge and Lotteries. Oxford: Oxford University Press.
Hinchman, Edward S. (2005) “Telling as Inviting to Trust.” Philosophy and Phenomenological Research 70: 562–87.
Hume, David. (1977) An Enquiry Concerning Human Understanding. Ed. Eric Steinberg. Indianapolis: Hackett.
Insole, Christopher J. (2000) “Seeing Off the Local Threat to Irreducible Knowledge by Testimony.” Philosophical Quarterly 50: 44–56.
Lackey, Jennifer. (1999) “Testimonial Knowledge and Transmission.” Philosophical Quarterly 49: 471–90.
———. (2003) “A Minimal Expression of Nonreductionism in the Epistemology of Testimony.” Noûs 37: 706–23.
———. (2005) “Testimony and the Infant/Child Objection.” Philosophical Studies 126: 163–90.
———. (2006a) “It Takes Two to Tango: Beyond Reductionism and Nonreductionism in the Epistemology of Testimony.” In Jennifer Lackey and Ernest Sosa (eds.), The Epistemology of Testimony. Oxford: Oxford University Press: 160–89.
———. (2006b) “Learning from Words.” Philosophy and Phenomenological Research 73: 77–101.
———. (2006c) “The Nature of Testimony.” Pacific Philosophical Quarterly 87: 177–97.
———. (2008) Learning from Words. Oxford: Oxford University Press.
Lehrer, Keith. (2006) “Testimony and Trustworthiness.” In Jennifer Lackey and Ernest Sosa (eds.), The Epistemology of Testimony. Oxford: Oxford University Press: 145–59.
Lipton, Peter. (1998) “The Epistemology of Testimony.” Studies in History and Philosophy of Science 29: 1–31.
Lyons, Jack. (1997) “Testimony, Induction and Folk Psychology.” Australasian Journal of Philosophy 75: 163–78.
McDowell, John. (1994) “Knowledge by Hearsay.” In Bimal Krishna Matilal and Arindam Chakrabarti (eds.), Knowing from Words. Dordrecht: Kluwer Academic: 195–224.
Millgram, Elijah. (1997) Practical Induction. Cambridge, MA: Harvard University Press.
Moran, Richard. (2006) “Getting Told and Being Believed.” In Jennifer Lackey and Ernest Sosa (eds.), The Epistemology of Testimony. Oxford: Oxford University Press: 272–306.
Nozick, Robert. (1981) Philosophical Explanations. Cambridge, MA: Belknap Press.
Owens, David. (2000) Reason without Freedom: The Problem of Epistemic Normativity. London: Routledge.
———. (2006) “Testimony and Assertion.” Philosophical Studies 130: 105–29.
Plantinga, Alvin. (1993) Warrant and Proper Function. Oxford: Oxford University Press.
Pollock, John. (1986) Contemporary Theories of Knowledge. Totowa, N.J.: Rowman and Littlefield.
Reed, Baron. (2006) “Epistemic Circularity Squared? Skepticism about Common Sense.” Philosophy and Phenomenological Research 73: 186–97.
Reid, Thomas. (1983) “Essay on the Intellectual Powers of Man.” In Ronald E. Beanblossom and Keith Lehrer (eds.), Thomas Reid’s Inquiry and Essays. Indianapolis: Hackett.
Reynolds, Steven L. (2002) “Testimony, Knowledge, and Epistemic Goals.” Philosophical Studies 110: 139–61.
Ross, Angus. (1986) “Why Do We Believe What We Are Told?” Ratio 28: 69–88.
Ross, James. (1975) “Testimonial Evidence.” In Keith Lehrer (ed.), Analysis and Metaphysics: Essays in Honor of R.M. Chisholm. Dordrecht: Reidel: 35–55.
Rysiew, Patrick. (2002) “Testimony, Simulation, and the Limits of Inductivism.” Australasian Journal of Philosophy 78: 269–74.
Schmitt, Frederick F. (1999) “Social Epistemology.” In John Greco and Ernest Sosa (eds.), The Blackwell Guide to Epistemology. Oxford: Blackwell: 354–82.
———. (2006) “Testimonial Justification and Transindividual Reasons.” In Jennifer Lackey and Ernest Sosa (eds.), The Epistemology of Testimony. Oxford: Oxford University Press: 193–224.
Sosa, Ernest. (1991) Knowledge in Perspective: Selected Essays in Epistemology. Cambridge: Cambridge University Press.
———. (2006) “Knowledge: Instrumental and Testimonial.” In Jennifer Lackey and Ernest Sosa (eds.), The Epistemology of Testimony. Oxford: Oxford University Press: 116–23.
Stevenson, Leslie. (1993) “Why Believe What People Say?” Synthese 94: 429–51.
Strawson, P.F. (1994) “Knowing from Words.” In Bimal Krishna Matilal and Arindam Chakrabarti (eds.), Knowing from Words. Dordrecht: Kluwer Academic: 23–27.
Van Cleve, James. (2006) “Reid on the Credit of Human Testimony.” In Jennifer Lackey and Ernest Sosa (eds.), The Epistemology of Testimony. Oxford: Oxford University Press: 50–74.
Webb, Mark Owen. (1993) “Why I Know About As Much As You: A Reply to Hardwig.” Journal of Philosophy 110: 260–70.
Weiner, Matthew. (2003) “Accepting Testimony.” Philosophical Quarterly 53: 256–64.
Welbourne, Michael. (1979) “The Transmission of Knowledge.” Philosophical Quarterly 29: 1–9.
———. (1981) “The Community of Knowledge.” Philosophical Quarterly 31: 302–14.
———. (1986) The Community of Knowledge. Aberdeen: Aberdeen University Press.
———. (1994) “Testimony, Knowledge and Belief.” In Bimal Krishna Matilal and Arindam Chakrabarti (eds.), Knowing from Words. Dordrecht: Kluwer Academic: 297–313.
Williams, Michael. (1999) Groundless Belief: An Essay on the Possibility of Epistemology. 2nd ed. Princeton: Princeton University Press.
Williamson, Timothy. (1996) “Knowing and Asserting.” Philosophical Review 105: 489–523.
———. (2000) Knowledge and Its Limits. Oxford: Oxford University Press.