I advocate a two part view concerning vagueness. On one hand I claim that vagueness is logically incoherent; but on the other hand I claim that vagueness is also a benign, beneficial, and indeed essential feature of human language and thought. I will call this view transvaluationism, a name which seems to me appropriate for several reasons. First, the term suggests that we should move beyond the idea that the successive statements in a sorites sequence can be assigned differing truth (...) values in some logically coherent way that fully respects the nature of vagueness -a way that [1] fully eschews any arbitrarily precise semantic transitions. We should transcend this impossible goal by accepting that vagueness harbors logical incoherence. Second, just as Nietzsche held that one can overcome nihilism by embracing what he called the transvaluation of all values, my position affirms vagueness, rather than despairing in the face of the logical absurdity residing at its very core. This affirmation amounts to a transvaluation of truth values, as far as sorites sequences are concerned. Third, the term 'transvaluationism' has a nice ring to it, especially since one of the principal philosophical approaches to vagueness is called supervaluationism. I will call the first claim of transvaluationism, that vagueness is logically incoherent, the incoherence thesis . I will call the second claim, that vagueness is benign, beneficial, and essential, the legitimacy thesis . The legitimacy thesis, taken by itself, seems overwhelmingly plausible; anyone who denies it assumes a heavy burden of proof. But prima facie, it seems dubious that the legitimacy thesis can be maintained in conjunction with the incoherence thesis. For, there is reason to doubt whether there is any cogent way to embrace the incoherence thesis without thereby becoming mired in what Williamson (1994) calls global nihilism about vagueness -the view that vague terms are empty (i.e., they do not, and cannot, apply to anything). Global nihilism, Williamson argues, has such destructively negative consequences that it does not deserve to be taken seriously -for instance, the consequence that vastly many of our common sense beliefs are false, and the consequence that these beliefs are not even useful (since the constituent terms in 'Common sense beliefs are useful' are vague and hence this statement turns out, given the [2] incoherence thesis, to be false itself). In short, the idea that one can adopt the incoherence thesis and then somehow transcend nihilism might initially seem hopelessly optimistic; transvaluationism would then be an unattainable, chimerical, goal rather than an intelligible and conceptually stable position concerning vagueness. Given certain widely held philosophical views about how language and thought must map onto the world in order for statements and the beliefs they express to be true -views that fall appropriately under the label 'referential semantics' -transvaluationism probably is a chimerical goal.. (shrink)

This work is in two parts. It began as a general investigation of vagueness in natural languages. The Sorites Paradox came to dominate the work however, and the second part of the book consists in an discussion ofthat puzzle and related problems. The first part contains a general discussion ofthe nature ofvagueness and its sources. I discuss various conceptions of vagueness in chapter 1 and outline some of the problems to do with the conception of vagueness as a linguistic phenomenon. (...) The most interesting of these is the Sorites paradox, which occurs where natural languages exhibit a particular variety of borderline case vagueness. I discuss some sources of vagueness of the borderline case variety, and views of the relation between linguistic behaviour and languages which are vague in this sense. I argue in chapter 2 that these problems are not to be easily avoided by statistical averaging techniques or attempts to provide a mathematical model of consensus in linguistic usage. I also consider in chapter 3 various approaches to the problem of providing an adequate logic and semantics for vague natural languages, and argue against two currently popular approaches to vagueness. These are supervaluation accounts which attempt to provide precise semantic models for vague languages based on the notion of specification spaces, and attempts to replace the laws ofclassical logic with systems offuzzy logic. (shrink)

Of course, although this view on meaning was the prevailing one for almost a century, many of the people who initiated the enterprise of logical semantics, including people like Frege and Wittgenstein, had an open eye for all that it did not catch. However, the logical means which Frege, Wittgenstein, Russell, and the generation that succeeded them, had at their disposal were those of classical mathematical logic and set-theory, and these indeed are not very suited for an analysis of other (...) aspects of meaning than those which the slogan covers. A real change in view then had to await the emergence of other concepts, which in due course became available mainly under the influence of developments in computer science and cognate disciplines such as artificial intelligence. And this is one of the reasons why it took almost a century before any serious and successful challenge of the view that meaning equals truthconditions from within logical semantics could emerge. (shrink)

This paper deals with the truth-Conditions and the logic for vague languages. The use of supervaluations and of classical logic is defended; and other approaches are criticized. The truth-Conditions are extended to a language that contains a definitely-Operator and that is subject to higher order vagueness.

Consider an object or property a and the predicate F. Then a is vague if there are questions of the form: Is a F? that have no yes-or-no answers. In brief, vague properties and kinds have borderline instances and composite objects have borderline constituents. I'll use the expression "borderline cases" as a covering term for both. ;Having borderline cases is compatible with precision so long as every case is either borderline F, determinately F or determinately not F. Thus, in addition (...) to borderline cases, vagueness requires "fuzzy borders". A has fuzzy borders if there is no sharp line between a's borderline cases, a's determinate cases and a's determinate non-cases. To illustrate, loudness is vague because in a continuum of gradually increasing volume, there is no fact about where the last definite loud noise is and where the first borderline noise is. ;Actual borderline cases are not required for vagueness. Suppose actual noises are either ear-shatteringly loud or silent. Even so, loudness is vague since it could have borderline instances. Just so for objects. Suppose a table is cleanly bounded such that there is a sharp break between the table and its surroundings. Still, that table is vague since there are worlds at which it is indeterminate whether some wood molecule a is, or is not, part of that table. ;There are three views about which things can be vague. On the linguistic view, vagueness is solely a feature of expressions. On the nihilistic view, nothing is vague because vagueness is incoherent. Pitted against these views is the ontological conception of vagueness according to which borderline instances and constituents arise due to genuine indeterminacy in nature. ;My dissertation defends the ontological conception. I argue against the adequacy of the theory's rivals, disarm a damaging objection and demonstrate the causal superiority of vague events. Anyone familiar with the literature on vagueness will notice that only a subset of issues are discussed. What I offer is preliminary--I hope only to make the theory of ontological vagueness attractive enough to merit future work. (shrink)