Abstract
Epistemic warrant is that property which converts true belief to knowledge. A theory of epistemic warrant known as "proper functionalism" has been developed recently by Alvin Plantinga. In this study I explore and evaluate Plantinga's new theory of epistemic warrant. In chapter one, I lay out in some detail Plantinga's proposed account of epistemic warrant. Chapters two through four are devoted to a careful consideration of critiques of proper functionalism by three of Plantinga's leading critics and Plantinga's responses to those criticisms. In chapters five and six, I develop my own criticisms of Plantinga's account, and contend that the conditions which Plantinga proposes in his account of warrant are neither jointly sufficient nor individually necessary for warrant.While proper functionalism is not satisfactory as a theory of epistemic warrant, it can be modified slightly and converted into an illuminating theory of rationality with respect to belief. In chapter seven I sketch a proper functionalist explication of an objective conception of rationality. Then in chapter eight I consider another conception of rationality, a subjective conception, which is parasitic upon that considered in chapter seven, and which thus significantly involves proper functionalist considerations.