Stephen Schiffer

Although there is a vast literature on whether propositional attitudes are relations to propositions, a crucial question that ought to lie at the heart of this debate is not often enough seriously addressed. This is the question of the contribution propositions make to the ways in which we benefit from having our propositional-attitude concepts, if those concepts are concepts of relations to propositions. Unless propositions can be shown to confer a benefit that no non-propositions could provide, we should probably doubt whether propositional attitudes really are relations to propositions. I believe that propositional attitudes are relations to propositions and that the role played by them in our conceptual economy cannot be played by things of any other kind, and in this paper I try to say why. This paper, in other words, offers my answer to the question posed by my title.

I. Vague Properties and the Problem of Vagueness The philosophical problem of vagueness is to say what vagueness is in a way that helps to resolve the sorites paradox. Saying what vagueness is requires saying what kinds of things can be vague and in what the vagueness of each kind consists. Philosophers dispute whether things of this, that, or the other kind can be vague, but no one disputes that there are vague linguistic expressions. Among vague expressions, predicates hold a special place in the problem of vagueness, for it’s their vagueness that is soritesgenerating. That puts the vagueness of predicates at the hub of the problem of vagueness, and there can be little doubt that we’ll be a short step from home if we can account for it. Any account of vagueness will of course require commitment to theses that are themselves foci of philosophical debate, but one can’t expect to get anywhere without taking on some as working hypotheses and then striving to say something that will be plausible if those hypotheses are plausible. One of the working hypotheses of this paper is that propositional attitudes and propositional speech acts are relations to propositions of some stripe or other, in the generic sense in which a proposition is an abstract, mind- and language-independent entity that has a truth condition, and has that truth condition both essentially and absolutely (i.e. without relativization to anything).1 The existence of propositions requires the existence of properties, in the generic sense in which a property is an abstract, mind- and language-independent entity that has an instantiation condition, and has that instantiation condition both essentially and absolutely. For present purposes it will be harmless to pretend that the propositions we believe and assert are Russellian propositions---structured entities whose basic constituents are the objects and properties our beliefs and speech acts are about. When a propositionalist speaks in loosey-goosey mode, she is apt to say that a sentence token is true just in case the proposition expressed in its utterance is true.

A single argument template---the EPH template---can be used to generate versions of the best known and most challenging skeptical problems. In his brilliantly groundbreaking book Knowledge and Its Limits, Timothy Williamson presents a theory of knowledge and evidence which he clearly intends to provide a response to skepticism in its most important forms. After laying out EPH skepticism and reviewing possible ways of responding to it, I show how elements of Williamson’s theory motivate a hitherto unexplored way of responding to EPH-generated skeptical arguments. Then I offer reasons to doubt the correctness of Williamson’s response

In The Things We Mean I argue that there exist such things as the things we mean and believe, and that they are what I call pleonastic propositions. The first two chapters offer an initial motivation and articulation of the theory of pleonastic propositions, and of pleonastic entities generally. The remaining six chapters bring that theory to bear on issues in the theory of content: the existence and nature of meanings; knowledge of meaning; the meaning relation and compositional semantics; the relation between content-involving facts and underlying physical facts; vagueness and indeterminacy; conditionals; normative discourse; and the role of propositional content in explanation, prediction, and knowledge acquisition.

Stephen Schiffer presents a groundbreaking account of meaning and belief, and shows how it can illuminate a range of crucial problems regarding language, mind, knowledge, and ontology. He introduces the new doctrine of 'pleonastic propositions' to explain what the things we mean and believe are. He discusses the relation between semantic and psychological facts, on the one hand, and physical facts, on the other; vagueness and indeterminacy; moral truth; conditionals; and the role of propositional content in information acquisition and explanation. This radical new treatment of meaning will command the attention of everyone who works on fundamental questions about language, and will attract much interest from other areas of philosophy.

SI is a paradox because it presents four appearances that cannot all be veridical: first, it appears to be valid—after all, it’s both classically and intuitionistically valid; second, its sorites premiss, (2), seems merely to state the obvious fact that in the sorites march from 2¢ to 5,000,000,000¢ there is no precise point that marks the cutoff between not being rich and being rich; third, premiss (1), which asserts that a person with only 2¢ isn’t rich, is surely true; and fourth, the conclusion (3), which asserts that a person with 5,000,000,000¢—i.e. $50 million—isn’t rich, is surely false.

S produces the sounds “It’s snowing” in the presence of A, and A instantaneously comes to know that it’s snowing. S has communicated to, or told, A that it’s snowing, and, as a result of S’s speech act, A came to know that it was snowing. Philosophical interest in communication turns on four inter-related questions. The first is about the logical structure of communication, or, more specifically, about whether communication is a relation that holds among three things just in case the first communicated the second to the third. The second is about the explication, or analysis, of communication. The third is about the role of communication in the explication of linguistic meaning. And the fourth is about how knowledge is acquired by communication. The questions are interrelated in that answers to any one question may constrain answers to one or more of the others.