Recently, it has been debated as to whether understanding is a species of explanatory knowledge. Those who deny this claim frequently argue that understanding, unlike knowledge, can be lucky. In this paper I argue that current arguments do not support this alleged compatibility between understanding and epistemic luck. First, I argue that understanding requires reliable explanatory evaluation, yet the putative examples of lucky understanding underspecify the extent to which subjects possess this ability. In the course of defending this claim, I also provide a new account of the kind of ‘grasping’ taken to be central to understanding. Second, I show that putative examples of lucky understanding unwittingly deploy a kind of luck that is compatible with knowledge. Finally, appealing to a number of works on explanation and its attendant epistemology, I argue that alleged instances of lucky understanding that overcome these two obstacles will invariably violate certain norms of explanatory inquiry – our paradigmatic understanding-oriented practice. By contrast, knowledge of the same information is immune to these criticisms. Consequently, if understanding is environmentally lucky, it is always inferior to the understanding that a corresponding case of knowledge would provide.

Jim Joyce has presented an argument for Probabilism based on considerations of epistemic utility. In a recent paper, I adapted this argument to give an argument for Probablism and the Principal Principle based on similar considerations. Joyce's argument assumes that a credence in a true proposition is better the closer it is to maximal credence, whilst a credence in a false proposition is better the closer it is to minimal credence. By contrast, my argument in that paper assumed (roughly) that a credence in a proposition is better the closer it is to the objective chance of that proposition. In this paper, I present an epistemic utility argument for Probabilism and the Principal Principle that retains Joyce's assumption rather than the alternative I endorsed in the earlier paper. I argue that this results in a superior argument for these norms.

Drawing on both empirical evidence and evolutionary considerations, Sperber et al. argue that humans have a suite of evolved mechanisms for ‘epistemic vigilance’. On their view, vigilance plays a crucial role in ensuring the reliability and hence the evolutionary stability of communication. This article responds to their argument for vigilance, drawing on additional empirical evidence (from deception detection research) and evolutionary considerations (from animal signalling research) to defend a more optimistic, quasi-Reidian view of communication. On this alternative view, the lion's share of the responsibility for explaining the reliability of testimony falls not to the vigilance of receivers but rather to the honesty of communicators, implying that vigilance does not play a major role in explaining the evolutionary stability of communication.

In ‘The Evolution of Testimony: Receiver Vigilance, Speaker Honesty and the Reliability of Communication,’ Kourken Michaelian questions the basic tenets of our article ‘Epistemic Vigilance’ (Sperber et al. 2010). Here I defend against Michaelian's criticisms the view that epistemic vigilance plays a major role in explaining the evolutionary stability of communication and that the honesty of speakers and the reliability of their testimony are, to a large extent, an effect of hearers' vigilance.

An influential view in the epistemology of testimony is that typical or paradigmatic beliefs formed through testimonial uptake are noninferential. Some epistemologists in particular defend a causal version of this view: that beliefs formed from testimony (BFT) are generated by noninferential processes. This view is implausible, however. It tends to be elaborated in terms that do not really bear it out – e.g. that BFT is fixed directly, immediately, unconsciously or automatically. Nor is causal noninferentialism regarding BFT plausibly expressed in terms of belief-independent belief formation; the complex cognitive details of BFT fixation do not accord well with such a view. But perhaps the most significant issue is that the relevant causal notion of inference itself is not particularly well-defined, at least with respect to BFT. Causal noninferentialism in this domain is obscure as a result, but this does not in turn clearly vindicate any interesting version of inferentialism.

Sarah Moss has recently suggested that when they encounter conflict, epistemic peers should not split the difference between the credence that they each assign to some disputed proposition p, as has been suggested by conciliatory approaches to belief revision in the debate surrounding disagreement in the literature. Moss contends that an epistemic compromise between peers need not be the arithmetic mean of prior credences, in the sense that if my credence in some proposition p is x and yours is y, the credence that is the result of our compromise need not be (x + y)/2. More generally, Moss's proposal advocates an approach to how estimations of truth value, exhibited in credences, should in fact be considered in resolving conflict and disagreement. The general idea is that splitting the difference between credences may be inadequate, seeing as agents may assign different epistemic values to different credences. While novel and clearly argued, I think that Moss's proposal fails to provide entirely convincing reasons for abandoning the traditional symmetrical approach to epistemic compromise and for adopting the scoring rule model instead. I demonstrate two problems with the model that Moss advocates.