 It thereby reflects the most powerful criticism that has been raised against the Nagel-model (see  Section 5.3).  Schaffner proposes a complex definition comprising several disjuncts, which are intended to encompass both genuine reductions and different sorts of replacement ranging from complete replacements via a continuum of relations to cases of correction fully within the reduced theory. Schaffner notes in many cases what gets strictly reduced in intermediate cases is not the original theory but a corrected version of that theory constructed within the vocabulary of the reducing theory.