Sorensen, Roy A [1988] 'Vagueness, Blurriness, and Measurement', Synthèse 75, pp. 45-82.

Attempts to resolve the sorites paradox typically require restrictions, revisions, or rejection of either classical logic or common sense. The only exception to this generalization is the epistemological approach developed by James Cargile and Richmond Campbell in [3] and [4]. They claim that vagueness is due to ignorance; although there is a sharp division point between, say, short and nonshort men, we do not know where the division point is. The main objection to this view is that Cargile and Campbell have not given a positive explanation of the source of this ignorance and they have not explained how vague predicates could have the unlimited sensitivity necessary to possess sharp division points. This paper is intended to lend support to the epistemological approach by providing criticisms of rival strategies and by showing how the explanatory gap can be filled by an appeal to "blurry" predicates. The paradoxes of vagueness can be traced back to Eubulides' paradox of the heap. Eubulides' paradox has the form of a mathematical induction. The base step of the induction is the claim that a collection of sand containing, say, one million grains of sand, is a heap. The induction step is the thesis that any heap remains a heap if only one grain of sand is removed from it. Classical logic allows us to validly infer from these two propositions that a collection of sand containing one grain of sand is a heap.