INTRODUCTION

My epistemological position can be described as naturalistic, or, with obvious latitude, as Copernican. It recognizes that a human being is a minute part of a universe which existed long before his birth and will survive long after his death; it considers human experience to be the result of complex interactions of human sensory apparatus with entities having careers independent of their being perceived; and it acknowledges the probability that the fundamental principles governing the natural order will seem extremely strange from the standpoint of ordinary human conceptions. In order to proclaim oneself a Copernican at the present stage in history, one admittedly does not have to be radical and nonconformist. Copernicanism is part of the generally accepted scientific world view, and it has been the doctrine of a number of philosophical schools, such as the American naturalists, the eighteenth-century materialists, the Lockean empiricists, and (anachronistically) the Greek atomists. Nevertheless, this familiar point of view is worthy of restatement, partly because it provides a perspective which can prevent narrowness in the technical investigations of philosophy of science and partly because its implications have by no means been exhaustively explored.

From the Copernican point of view it is natural to see two grand philosophical problems, which may be described by borrowing the vivid phrases of Heraclitus.