For a long time now, the study of negation has belonged to the discipline of logic. Linguists attempting to study negation have not ventured out of the confines of grammar. This work studies negation from a socio-cognitive point of view, treating negation as a cognitive process as well as a product of human interaction. The thesis invokes in large part, the stratificational approach to discourse proposed by Copeland and Davis which in turn is influenced by the Prague School and by text linguistics. Of primary concern in this work is the propositional blocking that typically characterizes negation together with the identification of some of the relational contexts in which blocking takes place. Four dominating contexts/functions of negation are proposed. They are: (1) denying presuppositions, (2) representing old information, (3) asserting new information without denying old information, and (4) giving expression to the speaker's attitudes, expectations, etc. The thesis also emphasizes that the above functions are not necessarily exhaustive. It does however, indicate a departure from older approaches to the study of negation.