"The concept of "ideology" did not originate in Marxism and is still in no way confined to it. Yet it is evidently an important concept in almost all Marxist thinking about culture., and especially about literature and ideas. The difficulty then is that we have to distinguish three common versions of the concept , which are all common in Marxist writing. These are broadly:
(i) a system of beliefs characteristic of a particular class or group;
(ii) a system of illusory beliefs - false ideas or false consciousness - which can be contrasted with true or scientific knowledge:
(iii) the general process of the production of meanings and ideas.
In one variant of Marxism, sense (i) and (ii) can be effectively combined. In a class society, all beliefs are founded on class position, and the systems of belief of all classes - or, quite commonly, of all classes preceding, and other than, the proletariat, whose formation is the project of the abolition of class society - are then in part or wholly false (illusory). The specific problems in this powrful general proposition have led to intense controversy within Marxist thought. It is not unusual to find some form of the proposition alongside uses of the simple sense (i), as in the characterization, for example by Lenin of 'socialist ideology'. Another way of broadly retainng but distinguishing senses (i) and (ii) is to use sense (i) for systems of belief founded on class position , including that of the proletariat within class society, and sense (ii) for contrast with (in a broad sense) scientific knowledge of all kinds, which is based on reality rather than illusions..."
CB