statements, objects, or subjects of the discourse. There exist internal relations among the signs (semiotic sequences) that are between and among the statements, objects, or subjects of the discourse. The term discursive formation identifies and describes written and spoken statements with semantic relations that produce discourses. As a researcher, Foucault applied the discursive formation to analyses of large bodies of knowledge, e.g. political economy and natural history. In The Archaeology of Knowledge (1969), a treatise about the methodology and historiography of systems of thought (“epistemes”) and of knowledge (“discursive formations”), Michel Foucault developed the concepts of discourse. The sociologist Iara Lessa summarizes Foucault's definition of discourse as "systems of thoughts composed of ideas, attitudes, courses of action, beliefs, and practices that systematically construct the subjects and the worlds of which they speak." Foucault traces the role of discourse in the legitimation of society's power to construct contemporary truths, to maintain said truths, and to determine what relations of power exist among the constructed truths; therefore discourse is a communications medium through which power relations produce men and women who can speak. The inter-relation between power and knowledge renders every human relationship into a power negotiation, because power is always present and so produces and constrains the truth. Power is exercised through rules of exclusion (discourses) that determine what subjects people can discuss; when, where, and how a person may speak; and determines which persons are allowed speak. That knowledge is both the creator of power and the creation of power, Foucault coined the term power-knowledge to show that an object becomes a "node within a network" of meanings. In The Archaeology of Knowledge, Foucault's example is a book's function as a node within a network meanings. The book does not exist as an individual object, but exists as part of a structure of knowledge that is "a system of references to other books, other texts, other sentences." In the critique of power–knowledge, Foucault identified Neo-liberalism as a discourse of political economy which is conceptually related to governmentality, the organized practices (mentalities, rationalities, techniques) with which people are governed. Interdiscourse studies the external semantic relations among discourses, because a discourse exists in relation to other discourses, e.g. books of history; thus do academic researchers debate and determine “What is a discourse?” and “What is not a discourse?” in accordance with the denotations and connotations (meanings) used in their academic disciplines. Discourse