This is disturbing only if we assume that states of consciousness are mutually exclusive. Insofar as the same subject can experience different forms of consciousness (dreams and waking reality) they need not be mutually exclusive; rather, the fear is that a totally different worldview, and therefore a totally different mode of operating in the world, may be appropriate. For example, it would be unsettling if someone managed to convince us that feudalism is the correct worldview and therefore the correct modus operandi. Our defence of the current worldview (industrial capitalism) would be motivated not only by apprehensions of the alteration in our individual condition (from factory-owner to serf) but perhaps even more by our belief in the props (e.g. belief in free speech and free enterprise) of the current worldview. Our values and beliefs are ultimately determined by our social existence; our knowledge of the world is based on our social relations and conditions.
The thesis he posited in contradistinction to Rene Descartes' "Cogito ergo sum" and which is central to Karl Marx's body of work is that "It is not the consciousness of men that determines their existence, but their social existence that determines their consciousness" (Critique of Political Economy 2). Existence itself does not depend on consciousness, much less on meta- consciousness; neither does life or productivity depend on consciousness. Rather, given a certain social structure and an individual's relations to it, subjective consciousness arises from physical reality. Physical reality encompasses everyday material activity (Burke 3), which is determined by the configuration of the individual or socioeconomic class in the current relations of production. An early 21st century American farmer's consciousness arises from the sum of all the activities and relationships he enters as a farmer (planting with a seed-drill, selling his grain to a corporate miller, buying seeds from a transnational biotechnology giant); it is different from the consciousness of the miller or the biotech company, and also from that of a farmer in Soviet Russia. It is different and unique not only because of his position in a salient mode of production (industrial capitalism versus socialism), but also, and equally importantly, because of the non-economic institutions that reflect and propagate that mode of production. Thus the early 21st century American farmer's consciousness is determined also by the media, the church, the system of education, the family - in short, by all that can be summed up as 'culture.'
Althusser calls these cultural institutions the Ideological State Apparatuses (ISAs) - in contrast to the Repressive State Apparatuses (Althusser 3) which operate by direct force (law, police, army). The ISAs grow up on the base of the mode of production, reflect it, and reinforce it; they represent the ideology of the dominant mode of production. This is true of every human society under every mode or production: it can be understood, not as a conspiracy (Burke 4), but as reflections in ideology of the mode of production. By reflecting the mode of production, ideology also propagates it: every time the status quo is mirrored in culture (e.g. in advertisements or