It is widely supposed that one family of sorites paradoxes, perhaps the most perplexing versions of the puzzle, owe at least in part to the nontransitivity of perceptual indiscriminability. To a first approximation, perceptual indiscriminability is the relationship obtaining among objects (stimuli) that appear identical in some perceptual respect—for example hue, or pitch, or texture. Indiscriminable objects look the same, or sound the same, or feel the same. Received wisdom has it that there are or could be series of objects (...) _o__1…_o__n in which _o_₁ and _o_₂ are indiscriminable, _o_₂ and _o_3 are indiscriminable, etc., and _o_n-1 and_ o_n are indiscriminable, but _o_1 and _o_n are discriminably different. For example, there could be a series of colored patches so ordered that each patch looks the same in hue as its immediate neighbors but the whole progresses from a clear case of red to a clear case of orange. On the assumption that an observational word like ‘red’ applies to both if to either of a pair of perceptually indiscriminable items, the absurd conclusion of the sorites comes into view. Crispin Wright explains. (shrink)

I distinguish two broad approaches to vagueness that I call "robust" and "wimpy". Wimpy construals explain vagueness as robust (i.e., does not manifest arbitrary precision); that standard approaches to vagueness, like supervaluationism or appeals to degrees of truth, wrongly treat vagueness as wimpy; that vagueness harbors an underlying logical incoherence; that vagueness in the world is therefore impossible; and that the kind of logical incoherence nascent in vague terms and concepts is benign rather than malignant. I describe some implications for (...) logic, semantics, and metaphysics. (shrink)

Discussions of higher-order vagueness rarely define what it is for a term to have nth-order vagueness for n>2. This paper provides a rigorous definition in a framework analogous to possible worlds semantics; it is neutral between epistemic and supervaluationist accounts of vagueness. The definition is shown to have various desirable properties. But under natural assumptions it is also shown that 2nd-order vagueness implies vagueness of all orders, and that a conjunction can have 2nd-order vagueness even if its conjuncts do not. (...) Relations between the definition and other proposals are explored; reasons are given for preferring the present proposal. (shrink)

There are many examples in the literature that suggest that indistinguishability is intransitive, despite the fact that the indistinguishability relation is typically taken to be an equivalence relation (and thus transitive). It is shown that if the uncertainty perception and the question of when an agent reports that two things are indistinguishable are both carefully modeled, the problems disappear, and indistinguishability can indeed be taken to be an equivalence relation. Moreover, this model also suggests a logic of vagueness that seems (...) to solve many of the problems related to vagueness discussed in the philosophical literature. In particular, it is shown here how the logic can handle the sorites paradox. (shrink)