Expression Plane

a linguistic term used in glossematics and by linguists of various schools to refer to an organized body of material means that represent linguistic messages. It is opposed to the content plane, which refers to the “world of thought” embodied in language, that is, the organized realm of everything that can be a subject of linguistic communciation.

In each plane, glossematics distinguishes between form and substance, dividing language into four spheres, or strata: form of expression, substance of expression, form of content, and substance of content. The form of both planes differs in every language and does not depend on the substance in which the form is manifested. The substance of each plane is defined through the concepts of form (the network of relationships between the elements of a given plane) and material (a certain mass of sounds, other elements, and ideas that is amorphous, and unsegmented but segmentable); the substance is treated as material that has been segmented by form.

The term “expression plane” is usually applied to the realm of sound phenomena, since the oral form of natural language is the chief object of study in linguistic analysis other than glossematics. Glossematic theory, on the other hand, stresses the equality of the phonetic, graphic (in written language), and other substances of expression in which the form of expression may be manifested.

The thesis of the isomorphism of linguistic levels is basic to glossematics. At the same time, glossematics regards the levels as not entirely parallel to each other, since in both linguistic planes, along with signifiers and the signified, there exist elements that cannot be correlated in a monosemantic way with entities of the opposite plane. This is precisely what justifies the division of natural language into an expression plane and a content plane; for other semiotic systems, whose inventory does not include nonsign units, such a division is unnecessary.