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...