This is a major conclusion from Saussure. At the very beginning of the essay he writes: "Some people regard language, when reduced to its elements, as a naming-process only-a list of words, each corresponding to the thing that it names....This conception is open to criticism at several points. It assumes that ready-made ideas exist before wards".
Structuralism notes that much of our imaginative world is structured of an structured by, binary oppositions and these oppositions structure meaning.
Saussure noted that "if words had the job of representing concepts fixed in advance, one would be able to find exact equivalents for them as between one language and another. But this is not the case". Reality is divided up into arbitrary categories by every language and the conceptual world with which each of us is familiar could have been divided hp very differently. Indeed, no two languages categorise reality in the same way. As John Pass more puts it, 'Languages differ by differentiating differently'. Linguistic categories are not simply a consequence of some predefined structure in the world. There are no 'natural' concepts or categories which are simply 'reflected' in language. Language plays a crucial role in 'constructing reality'.