Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Linguistics and Philosophy, 2005.Includes bibliographical references (p. 177-184).In this thesis, I advance a semantic theory of Neg-Raising rooted in the work of Bartsch (1973) and Heim (2000) and defend it against syntactic and pragmatic alternatives. The primary source of support for my position on Neg-Raising comes from the natural way in which the approach explains a variety of facts about NPI-licensing in environments containing Neg-Raising predicates. In Chapter 2, a principled account is offered of a previously ill-understood contrast in NPI-licensing under stacked Neg-Raising predicates, first pointed out in Horn (1972). Also addressed are facts advanced in favor of the syntactic theory of Neg-Raising by Kiparsky and Kiparsky (1970) and Prince (1976). Horn's (1989) attractive account of Neg-Raising is reviewed in detail in Chapter 3 and found to have deficiencies, particularly in the domain of NPI-licensing. The most compelling aspect of Horn's analysis is his derivation of Neg-Raising from general principles. The purposes of Chapters 4 and 5 is to develop an alternative analysis of Neg-Raising that attains a comparable depth of explanation. First, I compare the behavior of negated Neg-Raising predicates to that of negated definite plurals.(cont.) Next, I show that there is a significant correlation across constructions between obeying the Excluded Middle and having the properties of definite plurals. Finally, I offer a tentative explanation of why definite plurals obey the Excluded Middle.by Jon Robert Gajewski.Ph.D