Proposals for Future Developments in Fuzzy Set Technology

In the last 40 years, since fuzzy sets first entered the scientific and technological area, good theoretical progress (e.g. fuzzy logic, fuzzy probability theory, fuzzy topology, fuzzy algebra) has been made and technical advances in application systems (e.g. fuzzy control, fuzzy expert systems, fuzzy clustering and data mining) have emerged. Now, after these largely very revolutionary times, the theory of fuzzy sets and fuzzy application systems has become "normal" technology. What could the next step be in the evolution of fuzzy sets and soft computing? What is expected to happen in the theoretical development and its applications? The paper at hand offers a brief historical introduction to important milestones in fuzzy sets and systems. After this, we outline four scientific fields in which the theory of fuzzy sets may have good prospects: medicine and its philosophy, quantum mechanics and the philosophy of science. Finally we propose to conceptualize a network of theories of uncertainty that builds up on a basic theory of uncertainty-BUT- and consists of probability theory, quantum probability theory, fuzzy set theory and perhaps many more sophisticated theories of uncertainty.