Most philosophers believe that testimony is not a fundamental source of knowledge, but merely a way to transmit already existing knowledge. However, Jennifer Lackey has presented some counterexamples which show that one can actually come to know something through testimony that no one ever knew before. Yet, the intuitive idea can be preserved by the weaker claim that someone in a knowledge-constituting testimonial chain has to have access to some non-testimonial source of knowledge with regard to what is testified. But (...) even this weaker claim has a counterexample which I develop in close connection with a safety-account of knowledge. Thus, testimonial statements can sometimes enable us to know something for which none of our informants has any source of knowledge available. I conclude that my counterexample nevertheless does not affect the core of our intuitions about testimony, although it establishes that testimony can indeed be a fundamental source of knowledge. (shrink)

In this paper, I do three things. First, I offer an overview of an anti- luck epistemology, as set out in my book, Epistemic Luck. Second, I attempt to meet some of the main criticisms that one might level against the key theses that I propose in this work. And finally, third, I sketch some of the ways in which the strategy of anti- luck epistemology can be developed in new directions.

This paper describes the ways in which trolls and bots impede the acquisition of knowledge online. I distinguish between three ways in which trolls and bots can impede knowledge acquisition, namely, by deceiving, by encouraging misplaced skepticism, and by interfering with the acquisition of warrant concerning persons and content encountered online. I argue that these threats are difficult to resist simultaneously. I argue, further, that the threat that trolls and bots pose to knowledge acquisition goes beyond the mere threat of (...) online misinformation, or the more familiar threat posed by liars offline. Trolls and bots are, in effect, fake persons. Consequently, trolls and bots can systemically interfere with knowledge acquisition by manipulating the signals whereby individuals acquire knowledge from one another online. I conclude with a brief discussion of some possible remedies for the problem of fake persons. (shrink)

If knowledge requires safety, then one might think that when the epistemic source of knowledge is testimony, that testimony must itself be safe. Otherwise, will not the lack of safety transfer from testimony to hearer, such that hearer will lack knowledge? Resisting this natural line of reasoning, Goldberg (2005; 2007) argues that testimonial knowledge through unsafe testimony is possible on the basis of two cases. Lackey (2008) and Pelling (2013) criticize Goldberg’s examples. But Pelling goes on to provide his own (...) example that attempts to show that Goldberg’s thesis is true: one can gain safe testimonial belief from unsafe testimony. If any of these counterexamples were correct, they would undermine the main reason to think that knowledge based on unsafe testimony is impossible. My aim in this paper is to critically assess these arguments, and to consider the possibility of knowledge through unsafe testimony. Drawing a general moral from the analysis of these cases, I shall contend that it is impossible to acquire safe belief solely on the basis of unsafe testimony. If so, then testimonial knowledge based solely on unsafe testimony is impossible. (shrink)

Many epistemologists agree that even very young children sometimes acquire knowledge through testimony. In this paper I address two challenges facing this view. The first (building on a point made in Lackey (2005)) is the defeater challenge, which is to square the hypothesis that very young children acquire testimonial knowledge with the fact that children (whose cognitive immaturity prevents them from having or appreciating reasons) cannot be said to satisfy the No-Defeaters condition on knowledge. The second is the extension challenge, (...) which is to give a motivated, extensionally-adequate account of the conditions on testimonial knowledge in early childhood. Neither challenge can be met merely by endorsing externalism about knowledge; but we can meet both by reconceiving the process that eventuates in the child’s consumption of testimony. My central thesis is that this process should be seen as implicating features of the child's social environment. The result is a novel anti-individualistic externalism about knowledge. (shrink)

§§3-4 of the Begriffsschrift present Frege’s objections to a dominant if murky nineteenth-century semantic picture. I sketch a minimalist variant of the pre-Fregean picture which escapes Frege’s criticisms by positing a thin notion of semantic content which then interacts with a multiplicity of kinds of truth to account for phenomena such as modality. After exploring several ways in which we can understand the existence of multiple truth properties, I discuss the roles of pointwise and setwise truth properties in modal logic. (...) I argue that thinking of supertruth and determinate truth as setwise truth properties allows an understanding of supervaluationist approaches to vagueness which escapes both Williamson’s objections to and a needless metalinguistic orientation of traditional supervaluationism. (shrink)

Can one gain testimonial knowledge from unsafe testimony? It might seem not, on the grounds that if a piece of testimony is unsafe, then any belief based on it in such a way as to make the belief genuinely testimonial is bound itself to be unsafe: the lack of safety must transmit from the testimony to the testimonial belief. If in addition we accept that knowledge requires safety, the result seems to be that one cannot gain testimonial knowledge from unsafe (...) testimony. In a pair of recent papers, however, Sanford Goldberg has challenged this apparently plausible line of thought. Goldberg presents two examples intended to show that a testimonial belief can be safe, even if the testimony on which it is based is unsafe: the lack of safety need not transmit from the testimony to the testimonial belief. In this paper, I question whether Goldberg’s examples really do show that one can gain safe testimonial belief from unsafe testimony. The problem, I explain, is that both examples appear (for different reasons) to be open to objection. Nevertheless, I argue that although Goldberg’s examples do not establish his conclusion, the conclusion itself is true: one can gain safe testimonial belief from unsafe testimony. I base my argument on an example which differs in structure from Goldberg’s examples, and I argue that due to this difference, my example avoids the problems which Goldberg’s examples face. (shrink)