Iterating Definiteness

A central concept in the study of vagueness is the concept of a borderline case. This concept has its most basic application when we are faced with a question of the form ‘Is x F?’, but are unwilling to answer ‘Yes’ or ‘No’ for a certain distinctive kind of reason. Wanting to be co-operative, we need to say something; by saying ‘It’s a borderline case’, we excuse our failure to give a straightforward answer while conveying some information likely to be of interest to the questioner. The nature of the considerations that make us unwilling to answer ‘Yes’ or ‘No’ in these cases is a topic of central importance in the philosophy of vagueness. Different views about this naturally lead to different answers to the question what it means to be a borderline case. Before we can even broach this question, we need to settle on a way of regimenting borderlinenesstalk. There are two main approaches. On the first approach, the basic notion is metalinguistic in character, so that the task is that of making sense of locutions like these: