A term is vague if, and only if, it is capable of having borderline cases. All borderline cases are inquiry-resistant: Senator Hillary Clinton is a borderline case of "chubby" because, given her constitution, no amount of conceptual or empirical investigation can settle the question of whether or not she is chubby. Notice that this is not vagueness in the sense of being underspecific. If her spokesperson states that the senator weighs between 100 and 200 pounds, reporters will complain that the assertion is too obvious to be informative—not that the matter is indeterminate.

Typically, borderline cases lie between clear negative cases and clear positives. Moreover, the transition from clear to borderline cases will itself be unclear. If one thousand women queue in order of weight, there is no definite point at which the definitely non-chubby end and the borderline chubby begin. In addition to this second order vagueness: There...