The #purpose of invoking the notion of “purpose” is to emphasize the irrelevance of the #trajectories traced by such a system en route from an arbitrary initial #state to its #goal. In a synthesized system whose inner workings are known, this irrelevance has no significance. This irrelevance becomes highly significant, however when the analytic problem, the machine identification problem, cannot be solved, because, for instance, it is trans-computational in the sense that with known algorithms the number of elementary computations exceeds the age of the universe expressed in nanoseconds.

From #H_v_Foerster’s definition of CYBERNETICS in the Encyclopedia of Artificial Intelligence, Wiley, 1987, as presented in:

https://apps.dtic.mil/sti/tr/pdf/ADA171072.pdf