The useful effect is inseparably connected with the process of transportation, i.e., the productive process of the transport industry. Men and goods travel together with the means of transportation, and their traveling, this locomotion, constitutes the process of production effected by these means. The useful effect can be consumed only during this process of production. It does not exist as a utility different from this process, a use-thing which does not function as an article of commerce, does not circulate as a commodity, until after it has been produced. But the exchange-value of this useful effect is determined, like that of any other commodity, by the value of the elements of production (labour-power and means of production) consumed in it plus the surplus-value created by the surplus-labour of the labourers employed in transportation. This useful effect also entertains the very same relations to consumption that other commodities do. If it is consumed individually its value disappears during its consumption; if it is consumed productively so as to constitute by itself a stage in the production of the commodities being transported, its value is transferred as an additional value to the commodity itself. The formula for the transport industry would therefore be M---C< L MP ... P---M', since it is the process of production itself that is paid for and consumed, not a product separate and distinct from it. Hence this formula has almost the same form as that of the production of precious metals, the only difference being that in this case M' represents the converted form of the useful effect created during the process of production, and not the bodily form of the gold or silver produced in this process and extruded from it.
Industrial capital is the only mode of existence of capital in which not only the appropriation of surplus-value, or surplus-product, but simultaneously its creation is a function of capital. Therefore with it the capitalist character of production is a necessity. Its existence implies the class antagonism between capitalists and wage- labourers. To the extent that it seizes control of social production, the technique and social organisation of the labour-process are revolutionised and with them the economico-historical type of society. The other kinds of capital, which appeared before industrial capital amid conditions of social production that have receded into the past or are now succumbing, are not only subordinated to it and the mechanism of their functions altered in conformity with it, but move solely with it as their basis, hence live and die, stand and fall with this basis. Money-capital and commodity-capital, so far as they function as vehicles of particular branches of business, side by side with industrial capital, are nothing but modes of existence of the different functional forms now assumed, now discarded by industrial capital in the sphere of circulation -- modes which, due to social division of labour, have attained independent existence and been developed one-sidedly.
The circuit M ... M' on the one hand intermingles with the general circulation of commodities, proceeds from it and flows back into it, is a part of it. On the other hand it forms an independent movement of the capital-value for the individual capitalist, a movement of its own which takes place partly within the general circulation of commodities, partly outside of it, but which always preserves its independent character. First, because its two phases that take place in the sphere of circulation, M---Cand C'---M', being phases of the movement of capital, have functionally definite characters. In M---C, C is materially determined as labour-power and means of production; in C'---M' the capital-value is realised plus the surplus-value. Secondly, because P, the process of production, embraces productive consumption. Thirdly, because the return of the money to its starting-point makes of the movement M ... M' a circuit complete in itself.
Every individual capital is therefore, on the one hand, in its two circulation-halves M---C and C'---M', an agent of the general circulation of commodities, in which it either functions or lies concatenated as money or as a commodity, thus forming a link in the general chain of metamorphoses taking place in the world of commodities. On the other hand it describes within the general circulation its own independent circuit in which the sphere of production forms a transitional stage and in which this capital returns to its starting-point in the same form in which it left that point.
Within its own circuit, which includes its real metamorphosis in the process of production, it changes at the same time the magnitude of its value.
It returns not simply as money-value, but as augmented, increased money-value.
Let us finally consider M---C ... P ... C'---M' as a special form of the circular course of capital, alongside the other forms which we shall analyse later. We shall find that it is distinguished by the following features:
1. It appears as the circuit of money-capital , because industrial capital in its money-form , as money-capital, forms the starting-point and the point of return of its total process. The formula itself expresses the fact that the money is not expended here as money but is merely advanced, hence is merely the money-form of capital, money-capital.
It expresses furthermore that exchange-value, not use- value, is the determining aim of this movement. Just because the money-form of value is the independent, tangible form in which value appears, the form of circulation M ... M', the initial and terminal points of which are real money, expresses most graphically the compelling motive of capitalist production -- money-making.