“Language is [Roland] Barthes’s theme from beginning to end, and in particular the Saussurean insight that the sign is always a matter of historical and cultural convention. The ‘healthy’ sign, for Barthes, is one which draws attention to its own arbitrariness — which does not try to palm itself off as ‘natural’ but which, in the very moment of conveying a meaning, communicates something of its own relative, artificial status as well. The impulse behind this belief in the earlier work is a political one: signs which pass themselves off as natural, which offer themselves as the only conceivable way of viewing the world, are by that token authoritarian and ideological. It is one of the functions of ideology to ‘naturalize’ social reality, to make it seem as innocent and unchangeable as Nature itself. Ideology seeks to convert culture into Nature, and the ‘natural’ sign is one of its weapons. Saluting a flag, or agreeing that Western democracy represents the true meaning of the word ‘freedom’, become the most obvious, spontaneous responses in the world. Ideology, in this sense, is a kind of contemporary mythology, a realm which has purged itself of ambiguity and alternative possibility.
In Barthes’s view, there is a literary ideology which corresponds to this ‘natural attitude’, and its name is realism. Realist literature tends to conceal the socially relative or constructed nature of language: it helps to confirm the prejudice that there is a form of ‘ordinary’ language which is somehow natural. This natural language gives us reality ‘as it is’: it does not — like Romanticism or Symbolism — distort it into subjective shapes, but represents the world to us as God himself might know it. The sign is not seen as a changeable entity determined by the rules of a particular changeable sign system: it is seen rather as a translucent window on to the object, or on to the mind. It is quite neutral and colourless in itself: its only job is to represent something else, become the vehicle of a meaning conceived quite independently of itself, and it must interfere with what it mediates as little as possible. In the ideology of realism or representation, words are felt to link up with their thoughts or objects in essentially right and uncontrovertible ways: the word becomes the only proper way of viewing this object or expressing this thought.
The realist or representational sign, then, is for Barthes essentially unhealthy. It effaces its own status as a sign, in order to foster the illusion that we are perceiving reality without its intervention. The sign as ‘reflection’, ‘expression’ or ‘representation’ denies the productive character of language: it suppresses the fact that we only have a ‘world’ at all because we have language to signify it, and that what we count as ‘real’ is bound up with what alterable structures of signification we live within.”
— Terry Eagleton, “Post-Structuralism,” Literary Theory: An Introduction