Thirdly, if the movement of capital-value and surplus-value, which still proceeds unitedly in C and M, is separated only in part (a portion of the surplus-value not being spent as revenue) or not at all, a change takes place in the capital-value itself within its circuit, before it is completed. In our illustration the value of the productive capital was equal to £422. If that capital continues M---C, as, say, £480or £500, then it strides through the latter stages of its circuit with an increase of £58 or £78 over its initial value. This may also go hand in hand with a change in the composition of its value.
C'---M', the second stage of the circulation and the final stage of circuit I (M ... M'), is the second stage in our circuit and the first in the circulation of commodities. So far as the circulation is concerned, it must be complemented by M'---C'. But not only has C'---M' the process of self-expansion already behind it (in this case the function of P, the first stage), but its result, the commodity C'; has already been realised.
The process of the self-expansion of capital and the realisation of the commodities representing the expanded capital-value are therefore completed in C'---M'.
And so we have premised simple reproduction, i.e., that m---c separates entirely from M---C. Since both circulations, c---m---c as well as C---M---C, belong in the circulation of commodities, so far as their general form is concerned (and for this reason do not show only value differences in their extremes), it is easy to conceive the process of capitalist production, after the manner of vulgar economy, as a mere production of commodities, of use-values designed for consumption of some sort, which the capitalist produces for no other purpose than that of getting in their place commodities with different use-values, or of exchanging them for such, as vulgar economy erroneously states.
C' acts from the very outset as commodity-capital, and the purpose of the entire process, enrichment (the production of surplus-value), does not by any means exclude increasing consumption on the part of the capitalist as his surplus-value (and hence his capital) increases; on the contrary, it emphatically includes it.
Indeed, in the circulation of the revenue of the capitalist, the produced commodity c (or the fraction of the produced commodity C' ideally corresponding to it) serves only to transform it, first into money, and from money into a number of other commodities serving private consumption.
But we must not, at this point, overlook the trifling circumstance that c is commodity-value which did not cost the capitalist anything, an incarnation of surplus-labour, for which reason it originally stepped on the stage as a component part of commodity-capital C'. This c is, by the very nature of its existence, bound to the circuit of capital-value in process and if this circuit begins to stagnate or is otherwise disturbed, not only the consumption of c restricted or entirely arrested, but also the disposal of that series of commodities which serve to replace c. The same is true when C'---M' ends in failure, or only a part of C' can be sold.
We have seen that c---m---c, representing the circulation of the revenue of the capitalist, enters into the circulation of capital only so long as c is a part of the value of C', of capital in its functional form of commodity-capital; but, as soon as it acquires independence from m---c, hence throughout the form c---m---c, the circulation of that revenue does not enter into the movement of the capital advanced by the capitalist, although it stems from it. This circulation is connected with the movement of advanced capital inasmuch as the existence of capital presupposes the existence of the capitalist, and his existence is conditioned on his consuming surplus-value.
Within the general circulation C', for example yarn, functions only as a commodity; but as an element in the circulation of capital it performs the function of commodity-capital , a form which capital-value alternately assumes and discards. After the sale of the yarn to a merchant, it is extruded out of the circular movement of capital whose product it is, but nevertheless, as a commodity, it moves always in the sphere of the general circulation. The circulation of one and the same mass of commodities continues, in spite of the fact that it has ceased to be a phase in the independent circuit of the spinner's capital. Hence the real definitive metamorphosis of the mass of commodities thrown into circulation by the capitalist, C---M, their final exit into consumption may be completely separated in time and space from that metamorphosis in which this mass of commodities functions as his commodity-capital. The same metamorphosis which has been accomplished in the circulation of capital still remains to be accomplished in the sphere of the general circulation.
This state of things is not changed a bit if this yarn enters the circuit of some other industrial capital. The general circulation comprises as much the intertwining of the circuits of the various independent fractions of social capital, i.e., the totality of the individual capitals, as the circulation of those values which are not thrown on the market as capital but enter into individual consumption.