Each living ideological sign has two faces, like Janus. Any current curse word can become a word of praise, any current truth must inevitable sound to many other people as the greatest lie. This inner dialectical quality of the sign comes out fully in the open only during times of social crisis or revolutionary changes. In the ordinary conditions of life, the contradiction embedded in every ideological sign cannot fully emerge because the ideological sign in an established dominant ideology is always somewhat reactionary and tries, as it were, to stabilise the preceding factor in the dialectical flux of the social, generative process, so accentuating yesterday's truth so as to make it appear today's.
V.N. Vološinov, Marxism and the Philosophy of Language, p.23-4.