Let us see then what happens in reality. While, e.g., the 10,000 lbs. of yarn appear in the market as commodity-capital and are transformed into money (regardless of whether it is a paying or purchasing medium or only money of account), new cotton, coal, etc., take the place of the yarn in the process of production, have therefore already been reconverted from the money-form and commodity-form into that of productive capital, and begin to function as such. At the same time that these 10,000 lbs. of yarn are being reconverted into money, the preceding 10,000 lbs. of yarn are going through the second stage of their circulation and are being reconverted from money into the elements of productive capital. All parts of capital successively describe circuits, are simultaneously at its different stages.
The industrial capital, continuously progressing along its orbit, thus exists simultaneously at all its stages and in the diverse functional forms corresponding to these stages. That part of industrial capital which is converted for the first time from commodity-capital into money begins the circuit C' ... C', while industrial capital as a moving whole has already passed through that circuit. One hand advances money, the other receives it. The inauguration of the circuit M ... M' at one place coincides with the return of the money at another place. The same is true of productive capital.
The actual circuit of industrial capital in its continuity is therefore not alone the unity of the processes of circulation and production but also the unity of all its three circuits. But it can be such a unity only if all the different parts of capital can go through the successive stages of the circuit, can pass from one phase, from one functional form to another, so that the industrial capital , being the whole of all these parts, exists simultaneously in its various phases and functions and thus describes all three circuits at the same time. The succession ( das Nacheinander ), that is to say, by the division of capital. In a ramified factory system the product is constantly in the various stages of its process of formation and constantly passes from one phase of production to another. As the individual industrial capital has a definite size which depends on the means of the capitalist and which has a definite minimum magnitude for every branch of industry, it follows that its division must proceed according to definite proportions. The magnitude of the available capital determines the dimensions of the process of production, and this again determines the dimensions of the commodity-capital and money-capital in so far as they perform their functions parallel with the process of production. However co-existence, by which continuity of production is determined, is only due to the movement of those parts of capital in which they successively pass through their different stages. Co-existence is itself merely the result of succession.
If for instance C'---M' as far as one part is concerned, if the commodity cannot be sold, then the circuit of this part is interrupted and no replacement by its means of reproduction takes place; the succeeding parts, which emerge from the process of production in the shape of C', find the change of their functions blocked by their predecessors. If this lasts for some time, production is restricted and the entire process brought to a halt. Every stagnation in succession carries disorder into co-existence, every stagnation in one stage causes more or less stagnation in the entire circuit of not only the stagnant part of capital but also of the total individual capital.
The next form in which the process presents itself is that of a succession of phases, so that the transition of capital into a new phase is made necessary by its departure from another. Every separate circuit has therefore one of the functional forms of capital for its point of departure and point of return. On the other hand the aggregate process is in fact the unity of the three circuits, which are the different forms in which the continuity of the process expresses itself. The aggregate circuit presents itself to every functional form of capital as its specific circuit and every one of these circuits is a condition of the continuity of the total process. The cycle of each functional form is dependent upon the others.
It is a necessary prerequisite of the aggregate process of production, especially for the social capital, that it is at the same time a process of reproduction and hence a circuit of each one of its elements. Various fractional parts of capital pass successively through the various stages and functional forms. Thanks to this every functional form passes simultaneously with the others through its own circuit, although always a different part of capital finds its expression in it. One part of capital, continually changing, continually reproduced, exists as a commodity-capital which is converted into money; another as money-capital which is converted into productive capital; and a third as productive capital which is transformed into commodity-capital. The continuous existence of all three forms is brought about by the circuit the aggregate capital describes in passing through precisely these three phases.
Capital as a whole, then, exists simultaneously, spatially side by side, in its different phases. But every part passes constantly and successively from one phase, from one functional form, into the next and thus functions in all of them in turn. Its forms are hence fluid and their simultaneousness is brought about by their succession. Every form follows another and precedes it, so that the return of one capital part to a certain form is necessitated by the return of the other part to some other form.