Online research in philosophy

This paper presents and defends a definition of vagueness, compares it favourably with alternative definitions, and draws out some consequences of accepting this definition for the project of offering a substantive theory of vagueness. The definition is roughly this: a predicate 'F' is vague just in case for any objects a and b, if a and b are very close in respects relevant to the possession of F, then 'Fa' and 'Fb' are very close in respect of truth. The definition is extended to cover vagueness of many-place predicates, of properties and relations, and of objects. Some of the most important advantages of the definition are that it captures the intuitions which motivate the thought that vague predicates are tolerant, without leading to contradiction, and that it yields a clear understanding of the relationships between higher-order vagueness, sorites susceptibility, blurred boundaries, and borderline cases. The most notable consequence of the definition is that the correct theory of vagueness must countenance degrees of truth.

I go through, and criticize, Stephen Schiffer's account of vagueness and the sorites paradox. I discuss his notion of a happy-face solution to a paradox, his appeal to vagueness-related partial belief, his claim that indeterminacy is a psychological notion, and his view that the sorites premise and the inference rule of modus ponens are indeterminate.

ABSTRACT: Recently a bold and admirable interpretation of Chrysippus’ position on the Sorites has been presented, suggesting that Chrysippus offered a solution to the Sorites by (i) taking an epistemicist position1 which (ii) made allowances for higher-order vagueness.2 In this paper I argue (i) that Chrysippus did not take an epistemicist position, but − if any − a non-epistemic one which denies truth-values to some cases in a Sorites-series, and (ii) that it is uncertain whether and how he made allowances for higher-order vagueness, but if he did, this was not grounded on an epistemicist position.

Contextualism about vagueness (hereafter ‘Contextualism’) is the view that vagueness consists in a particular species of context-sensitivity and that properly accommodating this fact into our semantic theory will yield a plausible solution to the sorites paradox.[1],[2] But Contextualism, as many commentators have noted, faces the following immediate objection: if we hold the context fixed, vagueness still remains, therefore vagueness is not a species of context-sensitivity. Call this ‘the simple objection’.[3] Absent a convincing reply to the simple objection, Contextualism is in very bad shape. Oddly enough, defenders of Contextualism have said very little in reply. Proponents of the objection have tended to assume that this is because no reply is in the offing—the simple objection is taken to be unassailable. In this short paper, we sketch two replies to the simple objection which result in two very different kinds of Contextualism: Epistemicist Contextualism and Radical Contextualism. With these two theories in hand, the simple objection loses its force.

According to what I will call a contextualist solution to the sorites paradox, vague terms are context-sensitive, and one can give a convincing dissolution of the sorites paradox in terms of this context-dependency. The reason, according to the contextualist, that precise boundaries for expressions like “heap” or “tall for a basketball player” are so difficult to detect is that when two entities are sufficiently similar (or saliently similar), we tend to shift the interpretation of the vague expression so that if one counts as falling in the extension of the property expressed by that expression, so does the other. As a consequence, when we look for the boundary of the extension of a vague expression in its penumbra, our very looking has the effect of changing the interpretation of the vague expression so that the boundary is not where we are looking. This accounts for the persuasive force of sorites arguments.

I argue that for those who follow Evans in finding indeterminacy of de re identity statements problematic, ontic vagueness within a three-dimensionalist metaphysics will raise some problems that are not faced by the four-dimensionalist. For the types of strategies used to avoid de re indeterminacy within the context of ontic vagueness at-at-time, that is, spatial vagueness, are problematic within a three-dimensionalist framework when put to use within the context of ontic vagueness across-time, that is temporal vagueness.

Contextualism concerning vagueness (hereafter ‘CV’) is a popular response to the puzzle of vagueness.[1] The goal in this paper is to uncover in what ways vagueness may be a particular species of context-sensitivity. The most promising form of CV turns out to be a version of socalled ‘Non-Indexical Contextualism’.[2] In §2, we sketch a generic form of CV (hereafter ‘GCV’). In §3, we distinguish between Truth CV and Content CV. A non-indexical form of CV is a form of Truth CV, while an indexical form of CV is a form of Content CV. In §4, we argue that the theory of vagueness given in Fara (2000) is crucially incomplete but is best seen as a non-indexical form of CV. In §5, we set forth four kinds of error-theory to which CV might be committed. It turns out that Non-Indexical CV is committed to a weaker, and more plausible, error-theory than Indexical CV. In §6, we address a challenge posed by Keefe (2007) to the effect that CV entails that any speech report of what has been said by a particular vague utterance, where the context of utterance and the reporting context are relevantly different, will almost always be inaccurate. While this challenge is prima facie effective against Indexical CV it proves to be less effective against Non-Indexical CV. In §7, we look at two tests for context-sensitivity and assess whether they can be employed against CV. These tests, if cogent, reveal that the only workable form of CV is Non-Indexical CV.

Philosophers disagree about whether vagueness requires us to admit truth-value gaps, about whether there is a gap between the objects of which a given vague predicate is true and those of which it is false on an appropriately constructed sorites series for the predicate—a series involving small increments of change in a relevant respect between adjacent elements, but a large increment of change in that respect between the endpoints. There appears, however, to be widespread agreement that there is some sense in which vague predicates are gappy which may be expressed neutrally by saying that on any appropriately constructed sorites series for a given vague predicate there will be a gap between the objects of which the predicate is definitely true and those of which it is definitely false. Taking as primitive the operator ‘it is definitely the case that’, abbreviated as ‘D’, we may stipulate that a predicate F is definitely true (or definitely false) of an object just in case ‘DF (a)’, where a is a name for the object, is true (or false) simpliciter.1 This yields the following conditional formulation of a ‘gap principle’: (DΦ(x) ∧ D¬Φ(y)) → ¬R(x, y). Here ‘Φ’ is to be replaced with a vague predicate, while ‘R’ is to stand for a sorites relation for that predicate: a relation that can be used to construct a sorites series for the predicate—such as the relation of being just one millimetre shorter than for the predicate ‘is tall’. Disagreements about the sense in which it is correct to say that vague predicates are gappy can then be recast as disagreements about how to understand the definitely operator. One might give it, for example, a pragmatic construal such as ‘it would not be misleading to assert that’; or an epistemic construal such as ‘it is known that’ or ‘it is knowable that’; or a semantic construal such as ‘it is true that’.

In the introduction to their vagueness reader, Rosanna Keefe and Peter Smith classified accounts of vagueness with respect to how they handle the sorites paradox. The sorites paradox is set out in the standard way with reference to a sorites se- quence s of objects s1, . . . , sn and an associated vague predicate F . In S, there is a very small and seemingly negligible difference between any two adjacent elements si and si +1 with respect to the dimension that is relevant to satisfying F (for instance, if F is ‘. . . is tall’, then the dimension is height). This suggests that if si satisfies F , then so does si +1. Since S is a sorites sequence for F it is also stipulated that s1 satisfies F and that sn does not. Let ti denote si, 1 ≤ i ≤ n. Then the sorites argument is set up as..

Several philosophers offer explanations of linguistic vagueness by appealing to the referential context-dependence of vague terms. Timothy Williamson argues pre-emptively that any such approach must fail, on the grounds that context-dependence is neither necessary nor sufficient for vagueness. He supports this claim, in turn, by example. This paper argues that his examples fail to show that context-dependence is either unnecessary or insufficient for vagueness, and hence that he has failed by his own lights to show that it cannot explain vagueness.