In chapter 8, we noted that by treating vagueness-related ignorance as straightfor­wardly analogous to ignorance about the world, we concede much to the epistemicist way of thinking.

If we are truly to think of vagueness as something more than mere ignorance, we need to say something to preclude a purely epistemic interpretation of borderlineness.

Given that the nature of ordinary ‘worldly’ uncertainty is clarified by its role in decision theory, it is natural to think that the decision theory for vague propositions developed in chapter 9 could shed some light on this issue.

It is natural to think that a purely epistemic interpretation of vagueness would not distinguish in any meaningful way between the decision-theoretic role of a vague and a precise proposition. In this chapter, I shall argue that, although the formal theory of preferences might look the same, on a purely epistemic understanding of vagueness, Practical Irrelevance fails in a quite spectacular way: in terms of practical reasoning, there is very little to distinguish ordinary ignorance about the things that affect what we desire and ignorance about these things that is due to vagueness. For if vagueness is just a special kind of ignorance, then there is nothing to prevent us from finding vague matters themselves to be intrinsically desirable, much like we find other outcomes that we are ignorant about to be desirable. On the other hand, by denying the decision theoretic analogy between vague and precise desires, I shall argue, we open up the possibility for a partially bouletic interpretation of vagueness that does not identify it as merely a species of ignorance.

10.1  

More on the topic In chapter 8, we noted that by treating vagueness-related ignorance as straightfor­wardly analogous to ignorance about the world, we concede much to the epistemicist way of thinking.:

1. Vagueness-Related Uncertainty as a Special Sort ofPsychological Attitude
2. Critical thinking dispositions
3. Europeans did not deploy everywhere the full battery of institutions and techniques noted in chapter 12.
4. Disagreements about Morals, Conditionals, and Epistemic Modals