The entire capitalist system thus appears as a hierarchical structure of different levels of productivity, and as the outcome of the uneven and combined development of states, regions, branches of industry and firms, unleashed by the quest for surplus-profit. It forms an integrated unity, but it is an integrated unity of non-homogeneous parts, and it is precisely the unity that here determines the lack of homogeneity. In this whole system development and underdevelopment reciprocally determine each other, for while the quest for surplus-profits constitutes the prime motive power behind the mechanisms of growth, surplus-profit can only be achieved at the expense of less productive regions and branches of production.