Vagueness and Partial Belief

To solve the philosophical problem of vagueness is to solve two subproblems: the sorites paradox and the problem of explicating the notion of a borderline case (or the problem of explicating vagueness, since vagueness just is the possibility of borderline cases). In this paper I introduce a new kind of partial belief, vaguenessrelated partial belief (VPB), which I distinguish from the familiar kind of partial belief, standard partial belief (SPB), and bring it to bear on the two problems of vagueness.1 Underlying both applications is the idea that vagueness is neither a semantic nor an epistemic notion but rather a psychological notion.