Timothy Williamson, in various places, has put forward an argument that is supposed to show that denying bivalence is absurd. This paper is an examination of the logical force of this argument, which is found wanting.

Vagueness: an expression is vague if and only if it is possible that it give rise to a “borderline case.” A borderline case is a situation in which the application of a particular expression to a (name of) a particular object does not generate an expression with a definite TRUTH-VALUE. That is, the piece of language in question neither applies to the object nor fails to apply. Although such a formulation leaves it open what the pieces of language might be (...) (whole sentences, individual words, NAMES or SINGULAR TERMS, PREDICATES or GENERAL TERMS), most discussions have focussed on vague general terms and have considered other types of terms to be non-vague. (Exceptions to this have called attention to the possibility of vague objects, thereby making the designation relation for singular terms be vague). The formulation also leaves open the possible causes for the expression not to have a definite truth value. If this indeterminacy is due to there being insufficient information available to determine applicability or non-applicability of the term (that is, we’re convinced the term either does or doesn’t apply, but we just don’t have enough information to determine which), then this is sometimes called “epistemic vagueness.” It is somewhat misleading to call this vagueness, for unlike true vagueness, this epistemic vagueness disappears if more information is brought into the situation. (‘There are 1.89∞106 stars in the sky’ epistemically vague but is not vague in the generally accepted sense of the term). ‘Vagueness’ may also be used to characterize non-linguistic items such as CONCEPTS, MEMORIES, and OBJECTS ... as well as such semi-linguistic items as STATEMENTS and PROPOSITIONS. Many of the issues involved in discussing the topic of vagueness impinge upon other philosophical topics, such as the existence of TRUTH-VALUE GAPS (declarative sentences which are neither TRUE nor FALSE) and the plausibility of MANY-VALUED LOGIC.. (shrink)