The intention of this book is to connect two different areas of theory, and accordingly, it can be read from two different starting points. On one hand, it is a contribution to social theory. Modern society is understood as a functionally differentiated social system, with science being one of the subsystems of this comprehensive social system. The other starting point lies in discussions that have been ongoing since the mid-twentieth century under terms such as epistemology or theory of knowledge. Today, trends towards constructivist concepts are emerging here, which forgo idealistic or transcendental (and in this sense subjective) justifications, instead presupposing real systems that must orient their own observations based on their own constructions.