Abstract

This dissertation is an investigation into the nature of justification and rational belief. In Chapter I, four theories of the justification of belief are presented and criticized. These theories--classical foundationalism, modest foundationalism, coherentism, and the causal theory--are found to be similar in a certain respect. They each embody or are consistent with a certain conception of rationality, one in which beliefs are rational just in case they are backed by adequate justifications, and in which adequate justifications are thought to be mental entities composed of beliefs and inferences. It is argued that this conception of rationality and justification does not naturally generate an account of the social functions of justifications, of their role as the rational means for securing intrasubjective agreement. Motivated by this shortcoming, a fifth theory of justification, contextualism, is introduced. By conceiving of justifications as arguments--as structured sets of statements which one person offers to another--the contextualist proposes to give a theory of the adequacy of justification which will account for the social functions of justifications. In Chapter II, a contextual theory of justification is formulated. This theory consists, in part, of a set of necessary and sufficient conditions for the adequacy of justifications. According to the theory, a justification's adequacy is relative to the context in which it is given. And on this view, a particular justification is adequate relative to a certain context just in case it is adequate to fulfill two social goals: to convince the people to whom it is given that the person giving it is justified in accepting its conclusion and to convince them that they would be justified in accepting the conclusion. In Chapter III, the final chapter, a contextual theory of rational belief is developed and defended against the charge that its relativism renders rationality arbitrary. In this chapter, the conditions under which people are justified in believing particular statements are formulated. It is argued that all justified, rational beliefs rest ultimately on unjustified, arational ones. And a general theory of the nature of arational belief is offered