A cyberneticist or a cybernetician is a person who practices cybernetics.Heinz von Foerster once told Stuart Umpleby that Norbert Wiener preferred the term "cybernetician" rather than "cyberneticist", perhaps because Wiener was a mathematician rather than a physicist. On the other hand, Nicolas Rashevsky who began as a theoretical physicist, as well as Robert Rosen who began his career as a mathematician, regarded Neuro cybernetics--and more generally Biocybernetics-- as fields closely allied to Mathematical Biology and Mathematical Biophysics in which control theory and dynamical system theories also play significant roles.