Abstract
Parallel to the development of design methodology, various attempts were made to develop and formulate a theory of design with binding force for the discipline. While design methodology always had the declared goal of explaining the process of design itself and providing the necessary tools to optimize that process, the objective of design theory is more vague. Certainly one important task would be to use hypotheses or experiences to obtain the knowledge on which to base the discipline's general framework - knowledge that would address the questions of what design can do, what it should do, and what it wants to do.