Perhaps the most vexing problem in philosophy and social theory concerns the relative importance of material and ideal factors for social action. Karl Marx, for instance, with his notion of base and superstructure and his materialistic interpretation of the dialectic process, made a clean break from the idealism of his Hegelian heritage (McLellan 1977:390; Swingewood 1991:62–63). Nevertheless, idealism proved resilient and later came to inform the thinking of both actor-oriented (that is, phenomenologist, ethnomethodologist, symbolic interactionist) and structure-oriented (that is Functionalist, Structuralist) theorists.