Discourse refers to all the conditions required for the production of knowledge. Archaeology constructs its object past through the workings of discourse. This is a key concept in directing attention not so much to the content, but to the conceptual, social and historical conditions within which disciplines produce their statements, texts, knowledges and values. Discourse can be treated as the structured conditions within which statements may be made, texts constituted, interpretations made, knowledges developed, even people constituted as subjectivities. Discourse may consist of people, buildings, institutions, rules, values, desires, concepts, machines and instruments, ... . These are arranged according to systems and criteria of inclusion and exclusion, whereby some people are admitted, others excluded, some statements qualified as legitimate candidates for assessment, others judged as not worthy of comment. Disciplines mark areas of legitimate interest and supply procedural rules, patterns of acceptable practice. There are patterns of authority (committees and hierarchies for example) and systems of sanctioning, accreditation and legitimation (degrees, procedures of reference and refereeing, personal experiences, career paths). Discourses include media of dissemination: talk and speeches, books, papers, computer and information systems, galleries, or television and radio programmes. Archives (physical or memory-based) are built up providing reference and precedents. Metanarratives, grand systems of narrative, theory or explanation, often approaching myth, lie in the background and provide general orientation, framework and legitimation.