The Collected Works of Christian M.I.M. Matthiessen covers more than 35 years of work by one of the world's leading scholars in the systemic functional linguistics (SFL) school. It examines the nature, functions and structure of human language from a number of points of view within the framework of contemporary scientific thought. The series is organized into a number of distinct topics that reinforce each other, and together constitute a coherent, cutting-edge body of theoretical and descriptive work. VOLUME 1 provides the foundation for the whole series of collected works, and includes chapters that serve as introduction of and summaries of Systemic Functional Linguistics. It is concerned with the nature of systemic functional linguistics as theory, as framework and as a school of linguistics. It includes an overview of the organization or the architecture of language according to SFL and of the lexicogrammatical subsystem of language, and of Halliday's conception of language as a resource for making meaning. It is also concerned with the history and development of SFL. A new chapter written for this volume addresses the theme underpinning all chapters in the volume: the challenge of theorizing language. It introduces the metaphor of cartography, used by Matthiessen in his work on language, as a way of mapping linguistic theory, showing how all areas relate to one another.