In this chapter I shall attempt to summarize a number of studies on nomadic pastoralist societies which have been carried out either by myself or in collaboration with a team.1 The term nomadic pastoralist societies refers to a mode of subsistence that can be defined as the exploitation of a set of spatially dispersed vegetal resources, water, etc, by mobile herbivorous herds in search of their food (Bonte, 1973; Digard, 1973). These studies have a bearing upon a field of research that Marxist theory2 has almost completely ignored, despite the historical importance of such societies. They have represented an opportunity to subject this theory to a number of questions. For Marxist theory, in our opinion, cannot be considered a general theory directly applicable to the analysis of all human societies. We have refused to employ ready-made models, embodying an evolutionist ideology foreign to historical materialism, such as that found in the theory of the necessary succession of stages of human social organization, or those constructed by extrapolating from the specific analysis of the capitalist mode of production.3 In short, we admit that anthropology poses far more problems for historical materialist theory than the acquisition of this theory can resolve.