Finally the value of the constant part of capital, which continues in the productive process although the labour-process is interrupted, re-appears in the result of the productive process. Labour itself has here placed the means of production in conditions under which they pass of themselves through certain natural processes, the result of which is a definite useful effect or a change in the form of their use-value. Labour always transfers the value of the means of production to the product, in so far as it really consumes them in a suitable manner, as means of production. And it does not change the matter whether labour has to bear continually on its subject by means of the instruments of labour in order to produce this effect or whether it merely needs to give the first impulse by providing the means of production with conditions under which they undergo the intended alteration of themselves, in consequence of natural processes, without the further assistance of labour.
Whatever may be the reason for the excess of production time over the labour-time -- whether the circumstance that means of production constitute only latent productive capital and hence are still in a stage preliminary to the actual productive process or that their own functioning is interrupted within the process of production by its pauses or finally that the process of production itself necessitates interruptions of the labour-process --in none of these cases do the means of production function as absorbers of labour. And if they do not absorb labour, they do not absorb surplus-labour, either. Hence there is no expansion of the value of productive capital so long as it stays in that part of its production time which exceeds the labour-time, no matter how inseparable from these pauses the carrying on of the process of self-expansion may be. It is plain that the more the production time and labour-time cover each other the greater is the productivity and self-expansion of a given productive capital in a given space of time.
Hence the tendency of the capitalist production to reduce the excess of the production time over the labour-time as much as possible. But while the time of production of a certain capital may differ from its labour-time, it always comprises the latter, and this excess is itself a condition of the process of production. The time of production, then, is always that time in which a capital produces use-values and expands, hence functions as productive capital, although it includes time in which it is either latent or produces without expanding its value.
Within the sphere of circulation, capital abides as commodity-capital and money-capital. Its two processes of circulation consist in its transformation from the commodity-form into that of money and from the money-form into that of commodities. The circumstance that the transformation of commodities into money is here at the same time a realisation of the surplus-value embodied in the commodities, and that the transformation of money into commodities is at the same time a conversion or reconversion of capital-value into the form of its elements of production does not in the least alter the fact that these processes, as processes of circulation, are processes of the simple metamorphosis of commodities.
Time of circulation and time of production mutually exclude each other. During its time of circulation capital does not perform the functions of productive capital and therefore produces neither commodities nor surplus-value.
If we study the circuit in its simplest form, as when the entire capital-value passes in one bulk from one phase into another, it becomes palpably evident that the process of production and therefore also the self-expansion of capital-value are interrupted so long as its time of circulation lasts, and that the renewal of the process of production will proceed at a faster or a slower pace depending on the length of the circulation time. But if on the contrary the various parts of capital pass through the circuit one after another, so that the circuit of the entire capital-value is accomplished successively in the circuits of its various component parts, then it is evident that the longer its aliquot parts stay in the sphere of circulation the smaller must be the part functioning in the sphere of production. The expansion and contraction of the time of circulation operate therefore as negative limits to the contraction or expansion of the time of production or of the extent to which a capital of a given size functions as productive capital. The more the metamorphoses of circulation of a certain capital are only ideal, i.e., the more the time of circulation is equal to zero, or approaches zero, the more does capital function, the more does its productivity and the self-expansion of its value increase. For instance, if a capitalist executes an order by the terms of which he receives payment on delivery of the product, and if this payment is made in his own means of production, the time of circulation approaches zero.
A capital's time of circulation therefore limits, generally speaking, its time of production and hence its process of generating surplus-value.
And it limits this process in proportion to its own duration. This duration may considerably increase or decrease and hence may restrict capital's time of production in a widely varying degree. But Political Economy sees only what is apparent, namely the effect of the time of circulation on capital's process of the creation of surplus-value in general. It takes this negative effect for a positive one, because its consequences are positive.