The way physics and other parts of science work can be explained in the framework of radical constructivism. However, this constructivist view itself shows that a uniquily accepted epistemology, constructivism or any other, would not be an advantage for the developmentof science. Unlike physics some parts of science successfully use constructivist concepts inside their theories. Because this is the case particularly in learning theory, constructivist ideas can help to improve physics teaching.

Living systems are characterized as self-generating and self-maintaining systems. This type of characterization allows integration of a wide variety of detailed knowledge in biology.The paper clarifies general notions such as processes, systems, and interactions. Basic properties of self-generating systems, i.e. systems which produce their own parts and hence themselves, are discussed and exemplified. This makes possible a clear distinction between living beings and ordinary machines. Stronger conditions are summarized under the concept of self-maintenance as an almost unique character of living (...) systems. Finally, we discuss the far-reaching consequences that the principles of self-generation and self-maintenance have for the organization, structure, function, and evolution of single- and multi-cellular organisms. (shrink)