The claim of this paper is that the everyday functions of knowledge make most sense if we see knowledge as contrastive. That is, we can best understand how the concept does what it does by thinking in terms of a relation “a knows that p rather than q.” There is always a contrast with an alternative. Contrastive interpretations of knowledge, and objections to them, have become fairly common in recent philosophy. The version defended here is fairly mild in that there (...) is no suggestion that we cannot think in terms of a simpler not explicitly contrastive relation “a knows that p.” Some, for instance Schaffer (2005) and Karjalainen and Morton (2003), have hinted that this stronger possibility may be right. But all that I am arguing now is that facts that are easily expressed in contrastive terms are vital to understanding why we need the concept of knowledge. In a piece that is in some ways a companion to this one ("Contrastivism" in Duncan Pritchard and Sven Bernecker, eds. The Routledge Companion to Epistemology. Routledge 2010, 513-522), I give a general survey of theories of contrastive knowledge and the differences between them. (shrink)

We give a general description of a class of contrastive constructions, intended to capture what is common to contrastive knowledge, belief, hope, fear, understanding and other cases where one expresses a propositional attitude in terms of “rather than”. The crucial element is the agent's incapacity to distinguish some possibilities from others. Contrastivity requires a course-graining of the set of possible worlds. As a result, contrastivity will usually cut across logical consequence, so that an agent can have an attitude to p (...) rather than q but not to r rather than q , where r is a logical consequence of p . We relate these ideas to some general issues about thought, such as the question of whether all possibilities that can be distinguished in emotion can be distinguished in belief. (shrink)

This anthology of essays on the work of David Kaplan, a leading contemporary philosopher of language, sprang from a conference, "Themes from Kaplan," organized by the Center for the Study of Language and Information at Stanford University.

Does G. E. Moore know that he has hands? Yes, says the dogmatist: Moore’s hands are right before his eyes. No, says the skeptic: for all Moore knows he could be a brain-in-a-vat. Yes and no, says the contrastivist: yes, Moore knows that he has hands rather than stumps; but no, Moore does not know that he has hands rather than vat-images of hands. The dogmatist and the skeptic suppose that knowledge is a binary, categorical relation: s knows that p. (...) The contrastivist says that knowledge is a ternary, contrastive relation: s knows that p rather than q. (shrink)

Contextualism treats ‘knows’ as an indexical that denotes different epistemic properties in different contexts. Contrastivism treats ‘knows’ as denoting a ternary relation with a slot for a contrast proposition. I will argue that contrastivism resolves the main philosophical problems of contextualism, by employing a better linguistic model. Contextualist insights are best understood by contrastivist theory.

We describe the three place relation of contrastive knowledge, which holds between a person, a target proposition, and a contrasting proposition. The person knows that p rather than that q. We argue for three claims about this relation. (a) Many common sense and philosophical ascriptions of knowledge can be understood in terms of it. (b) Its application is subject to fewer complications than non-contrastive knowledge is. (c) It applies over a wide range of human and nonhuman cases.

Contrastivism is the claim that the knowledge relation is ternary, it relates three relata: a subject, a proposition, and a class of contrastive propositions. The present paper is a discussion of Jonathan Schaffer’s arguments in favour of contrastivism. The case is made that these are unconvincing: the traditional binary account of knowledge can handle the phenomena that ternarity is claimed to handle in a superior way.

Knowledge ascriptions are contrast-sensitive. One natural explanation for this is that the knowledge relation is contrastive ( s knows that p rather than q ). But can the binary view of knowledge ( s knows that p ) explain contrast-sensitivity? I review some of the linguistic data supporting contrast-sensitivity, and critique the three main binary explanations for contrast-sensitivity. I conclude that the contrast-sensitivity of knowledge ascriptions shows that knowledge is a contrastive relation.