Abstract

My dissertation argues that the beliefs, desires, and preferences that count as rational may change from one deliberative context to another. The argument rests on the premise that rational deliberation requires one to identify all the possibilities that are relevant to a decision problem. How does a decision maker accomplish this task? What impact does this demarcation have on the beliefs and desires that she uses to deliberate? The answers I propose suggest changes to the way we view rational agents and what they know. Appealing to empirical research and normative concerns, I argue that an agent's deliberative beliefs, desires, and preferences are "constructed'' on a case to case basis and are distinct from the agent's stable set of background attitudes. For deliberative judgments depend upon the ways one specifies what is relevant for a decision problem and this may change from one context to the next. Upon articulating a suitable context-sensitive view of rational decision making, I develop accounts of warranted assertion, rational full belief and knowledge that are similarly context-sensitive. These views criticize simple constitutive norms of assertion, like the knowledge norm, and propose a way to connect degrees of belief and full belief. In addition, the proffered account of knowledge explains how knowledge precludes epistemic luck, as required by Gettier cases, by appealing to the way the standards of knowledge vary from one deliberative context to the next.