Louis Hjelmslev's name for his theory of language. Like Ferdinand de Saussure, one of his key inspirations, Hjelmslev took the position that language is arbitrary in relation to the real world, which is to say there is nothing about a tree, for example, that necessitates it being called a tree, a fact that is amply proven by the great variety of different words different languages use for ostensibly the same object. By the same token, not all languages name things in the same way—his two demonstrations of this have become quite famous: the first compares Welsh and English words for colours, showing that the Welsh word ‘glas’ covers a spectrum of colours that in English would be shared between green, blue, and gray; the second compares Danish, German, and French words for trees individually and collectively and again shows that there is a disparity in the way they name the world. His conclusion, which has much in common with Saussure, was that words are signs and as such do not refer to the real world, but rather express our sense of it.
His comparison between languages served another, deeper purpose. Hjelmslev's ultimate goal with glossematics was to abstract what is common to all languages. Thus he compares the phrases ‘jeg véd det ikke’, ‘je ne sais pas’, and ‘I don't know’ in Danish, French, and English respectively and suggests that although constructed differently they can all be said to share a single thought or ‘purport’. The rather odd word ‘purport’ translates the Danish word ‘mening’, which might also have been rendered as meaning, although this too would have been problematic because it would have obscured the originality of Hjelmslev's theory. The French translation (the one Barthes, Deleuze, Greimas, and others relied on), which renders purport as ‘sens’, is perhaps a better choice, inasmuch that in English it implies both the words ‘meaning’ and ‘direction’ without implying direct intent as purport does. Julia Kristeva, among others, has criticized the notion of purport for preserving a transcendental element in what is otherwise meant to be an immanent theory of language.
For Hjelmslev, as a process purport is equivalent to substance, as though the intent of a particular statement is like clay that can be moulded into a variety of different forms. But, having said that, looked at from a system point of view, it does not have an independent existence—it can only be a substance insofar as it has form. Thus, in addition to content as substance, there is always a content-form as well that is independent of the content and forms it into a content substance. The shape of a building is, for all intents and purposes independent of the materials used to build it; but it is also constrained by those materials, in that there are only certain things concrete and steel can be made to do. Hjelmslev recognizes this and accounts for it in his system by adding a dimension of expression to his grid, again distinguishing system and process within it. As process, expression refers to the acquired limits in the range of references of particular words (as he points out, the Welsh ‘glas’ has a greater range of reference than its putative cognate in English ‘blue’); as system, he notes that the same sound can have different meanings in different languages (‘got’ in English sounds the same as ‘Gott’ (god) in German, but doesn't mean the same thing). Thus expression-purport and content-purport must be seen as independent of each other.