This two-volume set of studies takes as its starting point an old idea: the idea that universal grammar is based on meaning. It seeks to give this idea a solid theoretical foundation, and to explore its viability through detailed empirical studies in a set of typologically divergent languages (Lao, Malay, Mandarin Chinese, Mangaaba- Mbula, Polish and Spanish). As the twentieth century recedes, linguists seem increasingly to agree that the "anti-semantic turn" inaugurated by Leonard Bloomfield and continued by Noam Chomsky was a wrong turn. It is now widely believed that the grammatical properties of a word follow, at least in large measure, from its meaning. But it is true to say that in generative linguistics, semantics is still in a theoretically and methodologically underdeveloped state. It would not be going too far to compare much modern semantic work to phonology before the advent of phonemic analysis. There is little agreement on fundamental methodological problems such as how to distinguish semantic invariants from contextual effects, how to distinguish polysemy from semantic generality, and, above all, on the nature of semantic representation itself. All too often, individual researchers cobble together frameworks to suit their immediate needs, with little regard to how these frameworks can be integrated into a comprehensive system. Viewed against this background, the natural semantic metalanguage (NSM) framework stands out sharply (cf. Wierzbicka 1972, 1980, 1992, 1996; Goddard 1998; Goddard and Wierzbicka Eds 1994; and many other studies listed in this volume, chapter 1). It has been developed and refined over some thirty years. It provides a comprehensive system equally applicable to lexical, grammatical, and illocutionary meaning. It provides a clear and practical methodology for semantic analysis, which has proved itself in literally hundreds of studies in descriptive semantics.