Reason and Belief

Knowledge, Justification, and Reason-Based Belief

Is knowledge definable as justified true belief (“JTB”)? We argue that one can legitimately answer positively or negatively, depending on how the notion of justification is understood. To facilitate our argument, we introduce a simple propositional logic of reason-based belief. We show that this logic is sufficiently flexible to accommodate various useful features, including quantification over...

How to Reason about Self-Locating Belief

When reasoning about self-locating belief, one should reason as if one were a randomly selected bit of information. This principle can be considered to be an application of Bostrom’s Strong Self-Sampling Assumption(SSSA)[2] according to which one should reason as if one were a randomly selected element of some suitable reference class of observer-moments. The reference class is the class of all...

Cardinal Newman and Jury Verdicts: Reason, Belief, and Certitude

Using argumentation to reason about trust and belief

Trust is a mechanism for managing the uncertainty about autonomous entities and the information they store, and so can play an important role in any decentralized system. As a result, trust has been widely studied in multiagent systems and related fields such as the semantic web. Here we introduce a formal system of argumentation that can be used to reason using information about trust. This sy...

No Belief without Reason: Logics of Argument-Based Beliefs

The paper addresses how the information state of an agent relates to the arguments that the agent endorses. Information states are modeled in doxastic logic and arguments by recasting abstract argumentation theory in a modal logic format. The two perspectives are combined by an application of the theory of product logics, delivering sound and complete systems in which the interaction of argumen...