The second volume is devoted to issues of compositionality that arouse in the sciences of language, the investigation of the mind, and the modeling of representational brain functions. How could compositional languages evolve? How many sentences are needed to learn a compositional language? How does compositionality relate to the interpretation of texts, the generation of idioms and metaphors, and the understanding of aberrant expressions? What psychological mechanism underlies the combination of complex concepts? And finally, what neuronal structure can possibly realize a compositional system of mental representations?