THE CONTRAST - IN SENSITIVITY OF KNOWLEDGE ASCRIPTIONS Samuel

(1) Holmes knows that Mary stole the bicycle. Most philosophers of language with an interest in epistemology would have said, until very recently, that an utterance of (1) semantically expresses a proposition that is true if and only if Holmes (h) and the proposition that Mary stole the bicycle (p) are related by the binary relation of knowing (Kxy), so that the logical form of (1) is Khp. But in the past few years, a few plucky epistemologico-linguists, most notably Jonathan Schaffer, have tried to defend a contrasting view that has come to be known as " contrastivism ". 1 According to contrastivism, there is no such thing as a binary knowledge relation: rather, the knowledge relation is ternary, linking knowing subjects to two propositions rather than to one proposition. The version of contrastivism that has been defended by its proponents also assumes that the second " contrast " proposition is an unarticulated (or covert) constituent of the proposition semantically expressed by an utterance of the knowledge ascription, a constituent in some way determined by the context of utterance. Contrastivism, so understood, entails that the proposition semantically expressed by an 2 utterance of (1) in a context in which, say, the question at issue is whether Mary stole the bicycle or the wagon is identical to the proposition semantically expressed by an utterance of (2): (2) Holmes knows that Mary stole the bicycle rather than that Mary stole the wagon. On this view, the proposition semantically expressed by an utterance of (2) is true if and only if Holmes (h), the proposition that Mary stole the bicycle (p), and the proposition that Mary stole the wagon (q) are related by the ternary relation of knowing (Kxyz), so that the logical form of (2) is Khpq. As is now widely recognized, contrastivism has some notable theoretical advantages, even if what remains controversial is whether competitors to contrastivism (including contextualism and various forms of invariantism) possess the same or similar, and possibly more significant, advantages. 2 One advantage is that contrastivism can explain the appeal of skepticism about the external world without succumbing to skepticism or giving up on (at least some version of) the Principle of Closure in the process. 3 A second advantage is that contrastivism can explain what appear to be robust linguistic intuitions to the effect that the truth-value of an utterance of (1) varies across contexts. And …