Peter Pagin

Is observational indiscriminability non-transitive? This was once an accepted truth, and it was used by philosophers like Armstrong and Dummett to argue against the existence of appearances (sense data, sensory items). It was objected, however, early on by Jackson and Pinkerton, and more recently by vagueness contextualists like Raffman and Fara, that the case for non-transitivity is flawed. The reason is the context dependence of appearance. I argue here that if we take context dependence properly into account, we still have (a modified version of) non-transitivity, and that therefore we still face the problem of appearances.

This paper develops an idea of saving ordinary uses of vague predicates from the Sorites by means of domain restriction. A tolerance level for a predicate, along a dimension, is a difference with respect to which the predicate is semantically insensitive. A central gap for the predicate+dimension in a domain is a segment of an associated scale, larger than this difference, where no object in the domain has a measure, and such that the extension of the predicate has measures on one side of the gap and the anti-extension on the other. The domain restriction imposes a central gap.

The idea of higher-order vagueness is usually associated with conceptions of vagueness that focus on the existence of borderline cases. What sense can be made of it within a conception of vagueness that focuses on tolerance instead? A proposal is offered here. It involves understanding ‘definitely’ not as a sentence operator but as a predicate modifier, and more precisely as an intensifier, that is, an operator that shifts the predicate extension along a scale. This idea is combined with the author’s earlier approach to the semantics of vague expressions, which builds on the idea of a central gap associated with a predicate. The central gap approach is generalized to handle arbitrarily many iterations of ‘definitely’.