The central concern of this title, first published in 1994, is the syntactic nature of negation in Universal Grammar, and its relation to other functional elements in the Syntax. The study argues that negation is not a syntactic category on its own; rather, it is one of the values of a more abstract syntactic category, named Σ, which includes other sentence operators, such as affirmation and emphasis. This title will be of interest to students of language and linguistics.