After critically examining some major arguments both for and against NR (cf. Sec. 1), we have attempted the characterization of the putatively NR-triggering modal verbs, which proved to be strongly correlated with mood or modality (Sec. 2.2). In so doing, Horn\u27s mid-scalar hypothesis was shown to be basically useful in characterizing modal verbs sensitive to NR ; that is, verbs of the nonfactive class in the mid-scalar position (Sec. 2.1). Finally we have argued against NR as a transformational rule (Sec. 3). It turned out then that Negative Penetrability Principle, an interpretive principle in the sense of Jackendoff (1972), has greater descriptive adequacy in handling a wide range of the syntactic and semantic phenomena involving the varying degrees of negativity strength exhibited by various types of complement clauses
