Since many of the semantic relations that exist between clauses in complex sentences also exist between sentences in texts, a description of complex sentence processing should generalize to sentence processing in texts. This paper explores the usefulness of such a generalization for describing the online processing of sentences in narratives. Four experiments on the processing and retention of isolated complex sentences showed that connectives that signal a disruption in the causal and temporal order of propositions influence on-line processing and recall. Four additional experiments on the processing and retention of sentences in narratives showed that causal/ temporal relations within complex sentences and between sentences affect sentence reading time, and the immediate and long term memory organization of propositions. The results sugge partially independent processing systems for both isolated complex sentences and sentences in texts. One set of processes operates on superficial information to obtain a literal propositional representation; another operates on propositional information to obtain a thematic representation of the sentence or text. In general, factors that obscure the thematic relevance of a clause or sentence also indirectly affect the processing of propositional meaning.