In this paper we investigate a semantics for first-order logic originally proposed by R. van
Rooij to account for the idea that vague predicates are tolerant, that is, for the principle that if …

Supervaluationism is a well known theory of vagueness. Subvaluationism is a less well
known theory of vagueness. But these theories cannot be taken apart, for they are in a …

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 …

Vagueness is standardly opposed to precision. Just as gradable adjectives like 'tall'and a
quantity modifier like 'a lot'are prototypically vague expressions, mathematical adjectives like …

Many classically valid meta-inferences fail in a standard supervaluationist framework. This
allegedly prevents supervaluationism from offering an account of good deductive reasoning …

Paraconsistent approaches have received little attention in the literature on vagueness (at
least compared to other proposals). The reason seems to be that many philosophers have …

Debates concerning philosophical grounds for the validity of classical and intuitionistic
logics often have the very nature of logical proofs as one of the main points of controversy …

This paper is a tribute to Delia Graff Fara. It extends her work on failures of meta-rules
(conditional proof, RAA, contraposition, disjunction elimination) for validity as truth …

Qual è la natura della vaghezza? È un aspetto della comunicazione linguistica, della
conoscenza della realtà, o parte della realtà stessa? In queste pagine una chiara …

The naive theory of vagueness holds that the vagueness of an expression consists in its
failure to draw a sharp boundary between positive and negative cases. The naive theory is …