Almost everything we know depends in some way on testimony. Without the ability to learn from others, it would be virtually impossible for any individual person to know much beyond what has come within the scope of her immediate perceptual environment. The fruits of science, history, geography – all of these would be beyond our grasp, as would much of what we know about ourselves. We do not, after all, perceive that we belong to one family rather than to another – this is something we are told.

Despite the overwhelming importance of testimony, it has been neglected to a large extent in the philosophical tradition. Arguably, this has resulted from a general sense that our other cognitive faculties, such as perception, are more basic and therefore ought to be the primary focus of our investigations. In recent years, however, the idea that testimony is of secondary importance has been forcefully challenged, and new ways of thinking of testimony have been fruitfully explored by a number of philosophers. The present issue of Episteme aims to build on this body of work and to broaden it by incorporating insights from three different groups of people: philosophers who have already done considerable work in social epistemology, philosophers who are for the first time applying their work in other areas of epistemology to testimony, and psychologists who study the development of our ability to learn from others. The papers in this issue, with one exception, were delivered at the fourth annual Episteme conference, held at Rutgers University in June, 2007.

This paper considers how we decide whether to believe what we are told. Inference to the Best Explanation, a popular general account of non-demonstrative reasoning, is applied to this task. The core idea of this application is that we believe what we are told when the truth of what we are told would figure in the best explanation of the fact that we were told it. We believe the fact uttered when it is part of the best explanation of the fact of utterance. Having provided some articulation of this account of testimonial inference, the paper goes on to consider whether the account is informative and whether it is plausible.

In this paper I distinguish three degrees of epistemic egoism, each of which has an ethical analogue, and I argue that all three are incoherent. Since epistemic autonomy is frequently identified with one of these forms of epistemic egoism, it follows that epistemic autonomy as commonly understood is incoherent. I end with a brief discussion of the idea of moral autonomy and suggest that its component of epistemic autonomy in the realm of the moral is problematic.

What is the nature of children's trust in testimony? Is it based primarily on evidential correlations between statements and facts, as stated by Hume, or does it derive from an interest in the trustworthiness of particular speakers? In this essay, we explore these questions in an effort to understand the developmental course and cognitive bases of children's extensive reliance on testimony. Recent work shows that, from an early age, children monitor the reliability of particular informants, differentiate between those who make true and false claims and keep that differential accuracy in mind when evaluating new information from these people. We argue that this selective trust is likely to involve the mentalistic appraisal of speakers rather than surface generalizations of their behavior. Finally, we review the significance of children's deference to adult authority on issues of naming and categorization. In addition to challenging a purely inductive account of trust, these and other findings reflect a potentially rich set of tools brought by children to the task of learning from people's testimony.

Testimony is an indispensable source of information. Yet, contrary to ‘literalism’, speakers rarely mean just what they say; and even when they do, that itself is something the hearer needs to realize. So, understanding instances of testimony requires more than merely reading others' messages off of the words they utter. Further, a very familiar and theoretically well-entrenched approach to how we arrive at such understanding serves to emphasize, not merely how deeply committed we are to testimony as a reliable source of information, but that epistemological questions about testimonial belief are – perhaps even must be – posterior to such a commitment. This result does not itself dictate any particular views on the epistemology of testimony. However, not only does the failure of literalism not support the view that the justificatory basis of testimony-based beliefs is importantly inferential; it in fact undermines a key premise in one important argument for the view that one needs independent, positive reasons for accepting a given testimonial report. More generally, the present paper illustrates how discussions of the epistemology of testimony might usefully interact with an examination of the epistemology of understanding.

In trusting a speaker we adopt a credulous attitude, and this attitude is basic: it cannot be reduced to the belief that the speaker is trustworthy or reliable. However, like this belief, the attitude of trust provides a reason for accepting what a speaker says. Similarly, this reason can be good or bad; it is likewise epistemically evaluable. This paper aims to present these claims and offer a genealogical justification of them.

Tyler Burge offers a theory of testimony that allows for the possibility of both testimonial a priori warrant and testimonial a priori knowledge. I uncover a tension in his account of the relationship between the two, and locate its source in the analogy that Burge draws between testimonial warrant and preservative memory. I contend that this analogy should be rejected, and offer a revision of Burge's theory that eliminates the tension. I conclude by assessing the impact of the revised theory on the scope of a priori knowledge.

Sanford Goldberg has called our attention to an interesting problem: How is it that young children can learn from the testimony of their caregivers (their parents, teachers, and nannies, for example) even when the children themselves are undiscriminating consumers of testimony? Part One describes the importance and scope of the problem, showing that it generalizes beyond tots and their caregivers. Part Two considers and rejects several strategies for solving the problem, including Goldberg's own. Part Three defends a solution, positing a previously unnoticed social dimension to knowledge.

According to one widely held view, a belief is fully justified only if it holds up against the strongest available counterarguments, and we can be appropriately confident that it does hold up only if there is free and open critical discussion of those beliefs between us and our epistemic peers. In this paper I argue that this common picture of ideal rational group inquiry interacts with epistemic problems concerning reasonable disagreement in a way that makes those problems particularly difficult to resolve. By focusing on this idealized context, we get a clearer picture of the epistemic principles at issue. In the end, I argue that the best way to resolve the resulting epistemic conflicts is by appeal to the underdetermination of theory by evidence together with a principle of epistemic conservatism.

I present an account of what it is to trust a speaker, and argue that the account can explain the common intuitions which structure the debate about the transmission view of testimony. According to the suggested account, to trust a speaker is to grant her epistemic authority on the asserted proposition, and hence to see her opinion as issuing a second order, preemptive reason for believing the proposition. The account explains the intuitive appeal of the basic principle associated with the transmission view of testimony: the principle according to which, a listener can normally obtain testimonial knowledge that p by believing a speaker who testifies that p only if the speaker knows that p. It also explains a common response to counterexamples to this principle: that these counterexamples do not involve normal cases of testimonial knowledge.

Why is there so much misrepresentation of arguments in public forums? Standard explanations, such as self-interested biases, are insufficient. An additional part of the explanation is our commitment to, or belief in, norms that disallow responses that amount to no firm judgment, as contrasted with definite agreement or disagreement. In disallowing no-firm-judgment responses, these norms deny not only degrees of support or dissent and a variety of ways of suspending judgment, but also indifference. Since these norms leave us with only constricted options that are very intellectually demanding, in accepting these norms we impose on ourselves a pressure to justify our judgment that lends itself to relief through misrepresentation or distortion.