Found:

Unitary Base Hypothesis

MORPHOLOGY: a hypothesis proposed by Aronoff (1976) and Scalise (1984) which says that Word Formation Rules may only operate over a single type of syntactically or semantically defined base. This means that there may be affixation rules which attach an affix to the class of 'transitive verbs' or to the class of 'abstract nouns', but rules which attach an affix to both the class of 'transite verbs' and the class of 'abstract nouns' are ruled out.