Belief, Doubt, and Confidence: A Threshold Account

This dissertation assesses a thesis concerning the relationship between believing that something is the case and having confidence or sureness that something is the case. The thesis in question is the 'Threshold View': to believe that p (for any proposition p) is to have a high degree of confidence that p. If we accept the Threshold View and maintain that it is rational to be highly confident that p whenever one's total evidence very strongly favors p over not-p, then we must reject several currently prominent epistemological claims. One is that belief rationally ought to be withheld, even when one's evidence is very strong, if the cost of being wrong is sufficiently high. Another is that purely statistical evidence can never make belief rational. And a third is that whenever one holds inconsistent beliefs, not all of them can be rational. It has become common to reject the Threshold View to preserve these epistemological claims. This dissertation challenges that way of resolving the conflict.Part I of the dissertation develops accounts of belief, doubt, and confidence to be used in assessing the Threshold View. The account of belief (Chapter 1) is compatible with most but not all of the main approaches to belief in the existing philosophy of mind literature (it is incompatible with realizer functionalism, but compatible with role functionalism, representationalism, dispositionalism, and interpretationism). It is an account on which believing a proposition is a matter of having enough of the relevant dispositions, or having a representation that plays enough of the relevant functional role, etc. Belief is therefore vague: there are clear cases of belief, clear cases of non-belief, and borderline cases. A related account of doubt is developed in Chapter 2, and this account is extended in Chapter 3 to yield an account of confidence.Part II uses the accounts of belief, doubt, and confidence from Part I to assess the Threshold View. All of the major objections to the Threshold View are answered in Chapters 4 and 5. Chapter 4 replies to two non-epistemological objections to the Threshold View. Chapter 5 undermines the main arguments for the epistemological claims that conflict with the Threshold View. However, in Chapter 6 the accounts of belief and confidence are used to show that the Threshold View is probably false. But it emerges that a close cousin of the Threshold View--the 'Moderate Threshold Account'--is probably true. As the Moderate Threshold Account arguably has much the same epistemological consequences as the Threshold View, there is a case to be made for rejecting one or more of the epistemological claims that drive the epistemological arguments against the Threshold View.