Hilary Kornblith

Epistemology has changed dramatically since Descartes, but many of the questions epistemologists address today are no different from the questions Descartes addressed. I begin by raising four sets of questions with which Descartes concerned himself, and explain briefly why Descartes regarded these sets of questions as interchangeable. My main purpose, however, is not historical. Rather, I wish to present an outline of a naturalistic approach to these questions. I will not defend naturalistic epistemology. Instead, I hope to explore what a naturalistic approach to some traditional epistemological questions might look like; it is only through a better understanding of the consequences of naturalizing epistemology that we may hope properly to evaluate it. I will argue that questions which Descartes treated as interchangeable will have to be separated by naturalistically minded epistemologists. In the course of evaluating these questions from a naturalistic point of view, I hope to shed some light on the relation between reliability and justification, the dispute between internalist and externalist theories of justification, and the relation between ethics and epistemology.

We sometimes stop to reflect on our mental states, and such reflection can lead, at times, to changing our minds. It can, as well, lead us to endorse the very attitudes which we previously held. Such reflective endorsement has been called upon to play a wide range of roles in philosophical theorizing. It has been thought to ground a distinction between two fundamentally different kinds of knowledge: reflective knowledge and mere animal knowledge. It has been thought to serve as a ground for rational change of belief. It has been called upon to explain the possibility of freedom of the will. And it has been brought into service to explain the source of normativity. This chapter argues that it can play none of these roles.

Human beings form beliefs by way of a variety of psychological processes. Some of these processes of belief acquisition are innate; others are acquired. A good deal of interesting work has been done in assessing the reliability of these processes. Any such assessment must examine not only features intrinsic to the psychological processes themselves, but also features of the environments in which those processes are exercised; a mechanism which is reliable in one sort of environment may be quite unreliable in others. This is true not only of the physical environment; it is true of the social environment as well. This has important implications for how we should think about the exercise of individual reason, as well as the interpersonal practice of giving and asking for reasons