The most elementary definition of ideology is probably the well-known phrase from Marx's Capital: "Sie wissen das nicht, aber sie tun es" ("they do not know it, but they are doing it"). The very concept of ideology implies a kind of basic, constitutive naïveté: the misrecognition of its own presuppositions, of its own effective conditions, a distance, a divergence between so-called social reality and our distorted representation, our false consciousness of it. That is why such a 'naive consciousness' can be submitted to a critical-ideological procedure. The aim of this procedure is to lead the naïve ideological consciousness to a point at which it can recognize its own effective conditions, the social reality that it is distorting, and through this very act dissolve itself. In the more sophisticated versions of the critics of ideology -that developed by the Frankfurt School, for example — it is not just a question of seeing things (that is, social reality) as they 'really are', of throwing away the distorting spectacles of ideology; the main point is to see how the reality itself cannot reproduce itself without this so-called ideological mystification. The mask is not simply hiding the real state of things; the ideological distortion is written into its very essence.
Via René Z.