This is not an overly ambitious paper. What I would like to do is to take a thesis that most people would regard as wildly implausible, and convince you that it is, in fact, false. What's worse, the argument I shall give is by no means airtight, though I hope it's reasonably convincing. The thesis has to do with the fuzzy boundaries of terms that refer to familiar middle-sized objects, terms like ‘Kilimanjaro’ and ‘the tallest mountain in Africa.’ It is (...) intuitively clear that Kilimanjaro has a fuzzy boundary, so that there are some clods of earth at the base of the mountain for which there isn't anything, either in our practices in using the word ‘Kilimanjaro’ or in the facts of geography, that determines an answer to the question whether the clod is a part of Kilimanjaro. (shrink)

Some have argued that the vagueness exhibited by geographic names and descriptions such as ‘Albuquerque’, ‘the Outback’, or ‘Mount Everest’ is ultimately ontological: these terms are vague because they refer to vague objects, objects with fuzzy boundaries. I take the opposite stand and hold the view that geographic vagueness is exclusively semantic, or conceptual at large. There is no such thing as a vague mountain. Rather, there are many things where we conceive a mountain to be, each with its precise (...) boundary, and when we say ‘Everest’ we are just being vague as to which thing we are referring to. This paper defends this view against some plausible objections. (shrink)

Most speakers experience unclarity about the application of predicates like tall and red to liminal cases. We formulate alternative psychological hypotheses about the nature of this unclarity, and report experiments that provide a partial test of them. A psychologized version of the ‘vagueness-as-ignorance’ theory is then advanced and defended.

This piece gives an overview of the supervaluationist theory of vagueness. According to that theory, a sentence is true if and only if it is true on all ways of making it precise. This yields borderline case predications that are neither true nor false, but yet classical logic is preserved almost entirely. The article presents the view and some of its merits and briefly compares it with other theories of vagueness. It raises issues about higher-order vagueness and the definitely operator (...) and about the supervaluationist's accounts of truth and validity. (shrink)

Is it possible to maintain classical logic, stay close to classical semantics, and yet accept that language might be semantically indeterminate? The article gives an affirmative answer by Ramsifying classical semantics, which yields a new semantic theory that remains much closer to classical semantics than supervaluationism but which at the same time avoids the problematic classical presupposition of semantic determinacy. The resulting Ramsey semantics is developed in detail, it is shown to supply a classical concept of truth and to fully (...) support the rules and metarules of classical logic, and it is applied to vague terms as well as to theoretical or open-ended terms from mathematics and science. The theory also demonstrates how diachronic or synchronic interpretational continuity across languages is compatible with semantic indeterminacy. (shrink)

This book proposes a new solution to the problem of vagueness. There are several different ways of addressing this problem and no clear agreement on which one is correct. The author proposes that it should be understood as the problem of explaining vague predicates in a way that systematizes six intuitions about the phenomenon and satisfies three criteria of adequacy for an ideal theory of vagueness. The third criterion, which is called the “criterion of precisification”, is the most controversial one. (...) It is based on the intuition that a predicate is vague only if it is imprecise. The author considers some different definitions of linguistic imprecision, proposing that a predicate is imprecise if and only if there is no sharp boundary between objects to which its application yields some particular truth-value and objects to which its application does not yield that truth-value. The volume critically reviews the current theories of vagueness and proposes a new one, the Theory of Vagueness as Arbitrariness, which defines a vague predicate as an arbitrary predicate that must be precisified in order to contribute to a sentence that has truth-conditions. The main advantages of this theory over the current alternatives are that it satisfies all three criteria and systematizes the relevant intuitions. (shrink)

This paper motivates and explores an expressivist theory of vagueness, modelled on Allan Gibbard’s normative expressivism. It shows how Chris Kennedy’s semantics for gradable adjectives can be adjusted to fit into a theory on Gibbardian lines, where assertions constrain not just possible worlds but plans for action. Vagueness, on this account, is literally indecision about where to draw lines. It is argued that the distinctive phenomena of vagueness, such as the intuition of tolerance, can be explained in terms of practical (...) constraints on plans, and that the expressivist view captures what is right about several contending theories of vagueness. (shrink)

On standard versions of supervaluationism, truth is equated with supertruth, and does not satisfy bivalence: some truth-bearers are neither true nor false. In this paper I want to confront a well-known worry about this, recently put by Wright as follows: ‘The downside . . . rightly emphasized by Williamson . . . is the implicit surrender of the T-scheme’. I will argue that such a cost is not high: independently motivated philosophical distinctions support the surrender of the T- scheme, and (...) suggest acceptable approximations. (shrink)

According to Gupta and Belnap, the “extensional behavior” of ‘true’ matches that of a circularly defined predicate. Besides promising to explain semantic paradoxicality, their general theory of circular predicates significantly liberalizes the framework of truth-conditional semantics. The authors’ discussions of the rationale behind that liberalization invoke two distinct senses in which a circular predicate’s semantic behavior is explained by a “revision rule” carrying hypothetical information about its extension. Neither attempted explanation succeeds. Their theory may however be modified to employ a (...) relativized notion of extension. The resulting contextualist semantics for ‘true’ construes circularity as a pragmatic phenomenon. (shrink)

Proponents of supervaluationism claim super-truth, i. e., truth on every admissible precisification, is identical to truth or, at least, is a suitable truth proxy. I object that super-truth is neither identical to nor a suitable proxy for truth. I argue that to claim a statement is super-true is simply to maintain that a certain counterfactual holds, and that a claim is true, counterfactually, is no reason to treat it as true. I further argue that, with super-truth undermined, Roy Sorensen’s objection (...) that supervaluationism cannot accommodate vague directly referential terms presents supervaluationism’s defenders with a significant challenge. (shrink)

It’s not clear what supervaluationists should say about propositional content. Does a vague sentence, e.g., ‘Harry is bald’, express one proposition, or a barrage of propositions, or none at all? Or is the matter indeterminate? The supervaluationist canon is not decisive on the issue; authoritative passages can be cited in favor of each of the proposals just mentioned. Furthermore, some detractors have argued that supervaluationism is incapable of providing any coherent account of propositional content. This paper considers each of the (...) proposals for how many propositions are expressed by a vague sentence: none, some, all, or it’s indeterminate. Most of these proposals turn out to be unworkable in the metalanguage. I conclude that orthodox supervaluationists—those who identify truth with supertruth—must either relax the standard requirement that propositions be bivalent, or else alter the standard relation between sentences and propositions in which a sentence inherits its truth-conditions from the proposition it expresses. The best option going forward for the orthodox supervaluationist is perhaps the most surprising—amend the requirement that propositions be bivalent. I argue that propositions having supervaluational truth-conditions are best suited to fill the propositional roles in the semantic theory of a vague language. These propositions admit of truth-value gaps, and gappy propositions are controversial, but I argue that they earn their keep. (shrink)

According to an old and attractive view, vagueness must be eliminated before semantic notions — truth, implication, and so on — may be applied. This view was accepted by Frege, but is rarely defended nowadays.1 This..

Supervaluationism, traditionally conceived, is the conjunction of three theses: Vagueness in a language gives rise to there being a multitude of acceptable assignments of semantic values to some expressions of the language, These assignments correspond to possible completions of the meanings of vague expressions, Truth is truth under all acceptable assignments, and falsity is falsity under all acceptable assignments. Supervaluationism has three chief virtues. It preserves classical logic. It provides an account of what vagueness is . And it extends nicely (...) to the vagueness of singular terms. I argue, however, that the existence of vagueifiers ‐ expressions like‘roughly’– pose problems for thesis of Supervaluationism, and that the supervaluationist can get around these problems only at a serious cost. Toward the end of the paper, I present an alternative analysis of vagueness, which preserves the main virtues of Supervaluationism, but which identifies vagueness as semantic Overdetermination, rather than as semantic underdetermination. (shrink)

The logic of singular terms that refer to nothing, such as ‘Santa Claus,’ has been studied extensively under the heading of free logic. The present essay examines expressions whose reference is defective in a different way: they signify more than one entity. The bulk of the effort aims to develop an acceptable formal semantics based upon an intuitive idea introduced informally by Hartry Field and discussed by Joseph Camp; the basic strategy is to use supervaluations. This idea, as it stands, (...) encounters difficulties, but with suitable refinements it can be salvaged. Two other options for a formal semantics of multiply signifying terms are also presented, and I discuss the relative merits of the three semantics briefly. Finally, possible modifications to the standard logical regimentation of the notion of existence are considered. (shrink)

David Lewis has argued that impossible worlds are nonsense: if there were such worlds, one would have to distinguish between the truths about their contradictory goings-on and contradictory falsehoods about them; and this--Lewis argues--is preposterous. In this paper I examine a way of resisting this argument by giving up the assumption that ‘in so-and-so world’ is a restricting modifier which passes through the truth-functional connectives The outcome is a sort of subvaluational semantics which makes a contradiction ‘A & ~A’ false (...) even when both ‘A’ and ‘~A’ are true, just as supervaluational semantics makes a tautology ‘A v ~A’ true even when neither ‘A’ nor ‘~A’ are. Connections with discussive logics and complications of the account are discussed, and some general morals are drawn. (shrink)

Vagueness demands many boundaries. Each is permissible, in that a thinker may without error use it to distinguish objects, though none is mandatory. This is revealed by a thought experiment—scrambled sorites—in which objects from a sorites series are presented in a random order, and subjects are required to make their judgments without access to any previous objects or their judgments concerning them.

It is widely assumed that the methods and results of science have no place among the data to which our semantics of vague predicates must answer. This despite the fact that it is well known that such prototypical vague predicates as ‘is bald’ play a central role in scientific research (e.g. the research that established Rogaine as a treatment for baldness). I argue here that the assumption is false and costly: in particular, I argue one cannot accept either supervaluationist semantics, (...) or the criticism of that semantics offered by Fodor and Lepore, without having to abandon accepted, and unexceptionable, scientific methodology. (shrink)