Greimas begins by positing the existence of a "semantic universe" that he defined as the sum of all possible meanings that can be produced by the value systems of the entire culture of an ethno-linguistic community. As the semantic universe cannot possibly be conceived of in its entirety, Greimas was led to introduce the notion of "semantic micro-universe" and "discourse universe", as actualized in written, spoken or iconic texts. To come to grips with the problem of signification or the production of meaning, Greimas had to transpose one level of language (the "text") into another level of language (the "metalanguage") and work out adequate techniques of "transposition".