This chapter presents a model of the socio-political system that can be used to analyze the processes pertinent to understanding the human use of natural resources. The framework, drawn from the perspective of political economy, shows the relationship between surplus production, social class, the function of the state in promoting private accumulation, and the role of ideology in public discourse and development planning. The chapter illustrates how economic and political processes determine the way natural resources have been exploited in frontier regions of northern Brazil. It argues that both the design of intervention projects and the strategies to implement them must be formulated on the basis of a thorough assessment of a society's overall political economy. In some societies, such as certain indigenous groups in Amazonia, the goal of production is subsistence. The chapter summarizes the indigenous groups, Caboclos, and peasants share, to a greater or lesser extent, a production system oriented primarily to simple reproduction.