Why ‘believes’ is not a vague predicate

Abstract

According to what I call the 'Vagueness Thesis' ('VT') about belief, 'believes' is a vague predicate. On this view, our concept of belief admits of borderline cases: one can 'half-believe' something (Price in Belief, George Allen & Unwin, London, 1969) or be 'in-between believing' it (Schwitzgebel in Philos Q 51:76–82, 2001, Noûs 36:249–275, 2002, Pac Philos Q 91:531–553, 2010). In this article, I argue that VT is false and present an alternative picture of belief. I begin by considering a case—held up as a central example of vague belief—in which someone sincerely claims something to be true and yet behaves in a variety of other ways as if she believes that it is not. I argue that, even from the third-person perspective prioritised by proponents of VT, the case does not motivate VT. I present an alternative understanding of the case according to which the person in question believes as they say they do yet also has a belief-discordant implicit attitude otherwise. Moreover, I argue that, independently of the interpretation of any particular case, VT fails to accommodate the first-person perspective on belief. Belief is not only an item of one's psychology that helps explain one's behaviour; it is what one takes to be true. This fact about belief manifests itself in the nature of deliberation concerning whether to believe something and that of introspection regarding whether one believes something. Attending to these phenomena reveals that VT is not merely unmotivated, but untenable.