The diagram thus precludes the expansion of production by leaps and bounds. It only allows of a gradual expansion which keeps strictly in step with the formation of the surplus value and is based upon the identity between realisation and capitalisation of the surplus value. For the same reason, the diagram presumes an accumulation which affects both departments equally and therefore all branches of capitalist production. It precludes expansion of the demand by leaps and bounds just as much as it prevents a one-sided or precocious development of individual branches of capitalist production. Thus the diagram assumes a movement of the aggregate capital which flies in the face of the actual course of capitalist development. At first sight, two facts are typical for the history of the capitalist mode of production: on the one hand the periodical expansion of the whole field of production by leaps and bounds, and on the other an extremely unequal development of the different branches of production. The history of the English cotton industry from the first quarter of the eighteenth to the seventies of the nineteenth century, the most characteristic chapter in the history of the capitalist mode of production, appears quite inexplicable from the point of view of Marx's diagram. Finally, the diagram contradicts the conception of the capitalist total process and its course as laid down by Marx in _Capital_, volume iii. This conception is based on the inherent contradiction between the unlimited expansive capacity of the productive forces and the limited expansive capacity of social consumption under conditions of capitalist distribution. Let us see how Marx describes this contradiction in detail in chapter 15 on 'Unravelling the Internal Contradictions of the Law' (of the declining profit rate):