There are no limits to the continuation of this diagrammatic development of accumulation in accordance with the few easy rules we have demonstrated. But now it is time to take care lest we should only have achieved these surprisingly smooth results through simply working out certain fool-proof mathematical exercises in addition and subtraction, and we must further inquire whether it is not merely because mathematical equations are easily put on paper that accumulation will continue _ad infinitum_ without any friction. In other words: the time has come to look for the concrete social conditions of accumulation. FOOTNOTES: [96] 'The premise of simple reproduction, that I(_v + s_) is equal to II_c_, is irreconcilable with capitalist production, although this does not exclude the possibility that a certain year in an industrial cycle of ten or eleven years may not show a smaller total production than the preceding year, so that there would not have been even a simple reproduction, compared to the preceding year. Indeed, considering the natural growth of population per year, simple reproduction could take place only in so far as a correspondingly larger number of unproductive servants would partake of the 1,500 representing the aggregate surplus-product. But accumulation of capital, actual capitalist production, would be impossible under such circumstances' (_Capital_, vol. ii, p. 608). [97] Ricardo, _Principles_, chap. viii, 'On Taxes'. MacCulloch's edition of Ricardo's Works, p. 87, note. (Reference not given in original.)