Publisher Summary The chapter discusses metaphor, meaning, and Relational Frame Theory (RFT). The chapter discusses some of the empirical findings in the area of derived stimulus relations and its link to human language. It then provides a framework with which to understand the empirical phenomena. The framework, called Relational Frame Theory (RFT), views these empirical findings as the result of a particular kind of learned behavior, and argues that language and cognitive phenomena have their basis in this kind of behavior. RFT provides a basis for a behavioral account of some content domains commonly considered to be the province of cognitive psychology. The chapter extends the analysis to deal with two such topics: metaphor and meaning. Relational Frame Theory attempts to explain how complex stimulus functions emerge in language, and walks a middle path between referential and meaning-is-use accounts of verbal events. RFT can support an account of complex cognitive and verbal phenomena without abandoning the core of a behavioral approach.