Border-Line Cases, Vagueness, and Ambiguity

HIS paper is concerned with two closely related 1problems: the first is the general question of border-line cases; the second is a suggested identification of the notions of ambiguity and K.~. .'i vagueness. In the first part of the paper I propose to discuss border-line cases in the following way: I shall say what is meant by "border-line cases," discuss their genesis, enumerate and evaluate the different methods of resolving such cases, and make a brief comment or two the bearing, if any, that such cases have on logical theory. In the second part it will be suggested that the notion of vagueness can be reduced to the status of a special but important case of ambiguity; I hold that such a reduction would effect both an economy and a clarification. In the consideration of these problems, I shall make use in part of the terminology found in the monograph "Foundations of the Theory of Signs" by Professor C. W. Morris.' The specific terminology that will be used is the following. A sign may be said to denote any object which has certain properties . . as the sign "chair" denotes anything with a raised seat and a back