  The issue of averaging randomness is addressed, mostly in nuclear physics,
but shortly also in QCD. The Feshbach approach, so successful in dealing with
the continuum spectrum of the atomic nuclei ("optical model"), is extended to
encompass bound states as well ("shell model"). Its relationship with the
random-matrix theory is discussed and the bearing of the latter on QCD,
especially in connection with the spectrum of the Dirac operator, is briefly
touched upon. Finally the question of whether Feshbach's theory can cope with
the averaging required by QCD is considered.
