Some preliminary observations must be made concerning the nature and purpose of this study. What I have attempted here is an essay in the metaphysics of science, and not the "philosophy of science. " Rather than concentrating on the details of theory-construction and the for­ mal structure of scientific systems, I have treated science as an enter­ prise, a developing process within human experience. I have used such an approach in order to analyze science in its relationship to other human enterprises, such as art and philosophy, and to clarify its unique goals and characteristics. Often the concepts employed in descriptions of scientific methods are conceived too narrowly; by broadening the focus of attention I have attempted to characterize in a fairly general fashion the goals and methods of science. This has led to formulations which may seem at first glance to depart radically from some "well­ established" distinctions of the philosophy of science. I hope that it will be clear, however, that such formulations arise at a different level of analysis and concern very different problems from those of the logic of science. In particular, I am concerned with the general goals of science. These must not be confused with the narrower principles of method employed in science at any given time.