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. …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.

Terry Eagleton