It remains to test whether it is also valid for a capitalist economy. Here we must ask first of all: what is the starting point of accumulation? That is the approach on which we have to investigate the mutual dependence of the accumulative process in the two departments of production. There can be no doubt that under capitalist conditions Department II is dependent upon Department I in so far as its accumulation is determined by the additional means of production available. Conversely, the accumulation in Department I depends upon a corresponding quantity of additional consumer goods being available for its additional labour power. It does not follow, however, that so long as both these conditions are observed, accumulation in both departments is bound, as Marx's diagram makes it appear, to go on automatically year after year. The conditions of accumulation we have enumerated are no more than those without which there can be no accumulation. There may even be a desire to accumulate in both departments, yet the desire to accumulate plus the technical prerequisites of accumulation is not enough in a capitalist economy of commodity production. A further condition is required to ensure that accumulation can in fact proceed and production expand: the effective demand for commodities must also increase. Where is this continually increasing demand to come from, which in Marx's diagram forms the basis of reproduction on an ever rising scale? It cannot possibly come from the capitalists of Departments I and II themselves--so much is certain right away--it cannot arise out of their personal consumption. On the contrary, it is the very essence of accumulation that the capitalists refrain from consuming a part of their surplus value which must be ever increasing--at least as far as absolute figures are concerned--that they use it instead to make goods for the use of other people. It is true that with accumulation the personal consumption of the capitalist class will grow and that there may even be an increase in the total value consumed; nevertheless it will still be no more than a part of the surplus value that is used for the capitalists' consumption. That indeed is the foundation of accumulation: the capitalists' abstention from consuming the whole of their surplus value. But what of the remaining surplus value, the part that is accumulated? For whom can it be destined? According to Marx's diagram, Department I has the initiative: the process starts with the production of producer goods. And who requires these additional means of production? The diagram answers that Department II needs them in order to produce means of consumption in increased quantities. Well then, who requires these additional consumer goods? Department I, of course--replies the diagram--because it now employs a greater number of workers. We are plainly running in circles. From the capitalist point of view it is absurd to produce more consumer goods merely in order to