Doxastic resilience: on rational doubt, defeat, decision, and desire

Beliefs can be more or less supported by evidence. When the evidence speaks in favour of some proposition p, you can rationally be confident that p. On the Bayesian interpretation of doxastic states, this amounts to a high credence in p. But this cannot be the full account of confidence. Gaining evidence that supports the credence you already have improves your epistemic situation. Here, your credence level should remain unchanged, but the credence should become more resistant to change. Doxastic resilience measures your disposition to change credence in the face of incoming evidence.

The central claim of this thesis is that by thinking of confidence in terms of both the level and resilience of credences, we can make progress on several philosophical problems. After briefly introducing doxastic resilience in Chapter 1, I put the concept to use in four philosophical debates.

Chapter 2 offers an evidential account of rational resistance to counterevidence which contrasts with views according to which knowledge plays a special role in safeguarding against counterevidence. Chapter 3 argues that loss of resilience can influence rational decision-making, which sheds light on the normative significance of certain kinds of higher-order defeat. This contrasts with imprecise probability views on which higher-order defeat increases the imprecision of credence. Chapter 4 argues that higher-order uncertainty calibrates first-order credences and constrains expected resilience. This explains both higher-order confirmation and defeat. Chapter 5 shows that resilience bears on the expected value of inquiry. When unresilient, one should expect new evidence to be valuable. This explains cases where seemingly identical decision-relevant credences and utilities should nevertheless make different decisions when inquiry is feasible.