In general there are two distinct and separable meanings of the term "ideology" — the particular and the total. The particular conception of ideology… - Karl Mannheim

A modern theory of knowledge which takes account of the relational as distinct from the merely relative character of all historical knowledge must start with the assumption that there are spheres of thought in which it is impossible to conceive of absolute truth existing independently of the values and position of the subject and unrelated to the social context. Even a god could not formulate a proposition on historical subjects like 2 x 2 = 4, for what is intelligible in history can be formulated only with reference to problems and conceptual constructions which themselves arise in the flux of historical experience.

The particular conception of ideology operates primarily with a psychology of interests, while the total conception uses a more formal functional analysis, without any reference to motivations, confining itself to an objective description of the structural differences in minds operating in different social settings. The former assumes that this or that interest is the cause of a given lie or deception. The latter presupposes simply that there is a correspondence between a given social situation and a given perspective, point of view, or apperception mass. In this case, while an analysis of constellations of interests may often be necessary it is not to establish causal connections but to characterize the total situation. Thus interest psychology tends to be displaced by an analysis of the correspondence between the situation to be known and the forms of knowledge.

When the empirical investigator glories in his refusal to go beyond the specialized observation dictated by the traditions of his discipline, be they ever so inclusive, he is making a virtue out of a defense mechanism which insures him against questioning his presuppositions.