M', as the simple close of M ... M', and also C', as it appears
 within all these circuits, do not if taken by themselves express the movement
 but its result: the self-expansion of capital-value realised in the form
 of commodities or money, and hence, capital-value as M plus m, or C plus
 c, as a relation of capital-value to its surplus-value, as its offspring.
 They express this result as various circulation forms of the self-expanded
 capital-value. But neither in the form of C' nor of M' is the self-expansion
 which has taken place itself a function of money-capital or of commodity-capital.
 As special, differentiated forms, modes of existence corresponding to special
 functions of industrial capital, money-capital can perform only money-functions
 and commodity-capital only commodity-functions, the difference between
 them being merely that between money and commodity. Similarly industrial
 capital in its form of productive capital can consist only of the same
 elements as those of any other labour-process which creates products: on
 the one hand objective conditions of labour (means of production), on the
 other productively (purposively) functioning labour-power. Just as industrial
 capital can exist in the sphere of production only in a composition which
 meets the requirements of the production process in general, hence also
 of the non-capitalist production process, so it can exist in the sphere
 of circulation only in the two forms corresponding to it,
 viz., that of a commodity and of money. But just as the totality of the
 elements of production announces itself at the outset as productive capital
 by the fact that the labour-power is labour-power that belongs to others
 and that the capitalist purchased it from its proprietor, just as he purchased
 his means of production from other commodity-owners; just as therefore
 the process of production itself appears as a productive function of industrial
 capital, so money and commodities appear as forms of circulation of the
 same industrial capital, hence their functions appear as the functions
 of circulation, which either introduce the functions of productive capital
 or emanate from them. Here the money-function and the commodity-function
 are at the same time functions of commodity-capital, but solely because
 they are interconnected as forms of functions which industrial capital
 has to perform at the different stages of its circuit. It is therefore
 wrong to attempt to derive the specific properties and functions which
 characterise money as money and commodities as commodities from their quality
 as capital, and it is equally wrong to derive on the contrary the properties
 of productive capital from its mode of existence in means of production.