Contrastivism is the view that knowledge is a ternary relation between an agent, a content proposition, and a contrast, and it explains that a binary knowledge ascription sentence appears to be context-sensitive because different contexts can implicitly fill the contrast with different values. This view is purportedly supported by certain linguistic evidence. An objective of this paper is to argue that contrastivism is not empirically adequate, as there are examples that favor its contextualist cousin. Thereafter, I shall develop a contextualist (...) account for the relevant linguistic data. The account consists of a contextualist semantics and some rules of pragmatics. The two parts combined show that contrastivism is neither sufficient nor necessary as a satisfactory theory of knowledge ascriptions. (shrink)

Many epistemologists have been attracted to the view that knowledge-wh can be reduced to knowledge-that. An important challenge to this, presented by Jonathan Schaffer, is the problem of “convergent knowledge”: reductive accounts imply that any two knowledge-wh ascriptions with identical true answers to the questions embedded in their wh-clauses are materially equivalent, but according to Schaffer, there are counterexamples to this equivalence. Parallel to this, Schaffer has presented a very similar argument against binary accounts of knowledge, and thereby in favour (...) of his alternative contrastive account, relying on similar examples of apparently inequivalent knowledge ascriptions, which binary accounts treat as equivalent. In this article, I develop a unified diagnosis and solution to these problems for the reductive and binary accounts, based on a general theory of knowledge ascriptions that embed presuppositional expressions. All of Schaffer's apparent counterexamples embed presuppositional expressions, and once the effect of these is taken into account, it becomes apparent that the counterexamples depend on an illicit equivocation of contexts. Since epistemologists often rely on knowledge ascriptions that embed presuppositional expressions, the general theory of them presented here will have ramifications beyond defusing Schaffer's argument. (shrink)

Knowledge ascriptions seem context sensitive. Yet it is widely thought that epistemic contextualism does not have a plausible semantic implementation. We aim to overcome this concern by articulating and defending an explicit contextualist semantics for ‘know,’ which integrates a fairly orthodox contextualist conception of knowledge as the elimination of the relevant alternatives, with a fairly orthodox “Amherst” semantics for A-quantification over a contextually variable domain of situations. Whatever problems epistemic contextualism might face, lack of an orthodox semantic implementation is not (...) among them. (shrink)

We report and discuss the results of a series of experiments that address a contrast effect exhibited by folk judgments about knowledge ascriptions. The contrast effect, which was first reported by Schaffer and Knobe, is an important aspect of our folk epistemology. However, there are competing theoretical accounts of it. We shed light on the various accounts by providing novel empirical data and theoretical considerations. Our key findings are, firstly, that belief ascriptions exhibit a similar contrast effect and, secondly, that (...) the contrast effect is systematically sensitive to the content of what is in contrast. We argue that these data pose significant challenges to contrastivist accounts of the contrast effect. Furthermore, some of the data set provides, in conjunction with some non-empirical epistemological arguments, some limited evidence for what we call a focal bias account of the data. According to the focal bias account, the contrast effects arise at least in part because epistemically relevant facts are not always adequately processed when they are presented in certain ways. (shrink)

According to one form of epistemic contrastivism, due to Jonathan Schaffer, knowledge is not a binary relation between an agent and a proposition, but a ternary relation between an agent, a proposition, and a context-basing question. In a slogan: to know is to know the answer to a question. I argue, first, that Schaffer-style epistemic contrastivism can be semantically represented in inquisitive dynamic epistemic logic, a recent implementation of inquisitive semantics in the framework of dynamic epistemic logic; second, that within (...) inquisitive dynamic epistemic logic, the contrastive ternary knowledge operator is reducible to the standard binary one. The reduction shows, I argue, that Schaffer’s argument in favor of contrastivism is compatible with a binary picture of knowledge. This undercuts the force of the argument in favor of contrastivism. (shrink)

The paper examines the logic and semantics of knowledge attributions of the form “s knows whether A or B”. We analyze these constructions in an epistemic logic with alternative questions, and propose an account of the context-sensitivity of the corresponding sentences and of their presuppositions.