However this appropriation of surplus-value, or this separation of the production of value into a reproduction of advanced value and a production of new value (surplus-value) which does not replace any equivalent, does not alter in any way the substance of value itself or the nature of the production of value. The substance of value is and remains nothing but expended labour-power -- labour independent of the specific, useful character of this expenditure. A serf for instance expends his labour-power for six days, labours for six days, and the fact of this expenditure as such is not altered by the circumstance that he may be working three days for himself, on his own field, and three days for his lord, on the field of the latter.
Both his voluntary labour for himself and his forced labour for his lord are equally labour; so far as this labour is considered with reference to the values, or to the useful articles created by it, there is no difference in his six days of labour. The difference refers merely to the different conditions by which the expenditure of his labour-power during both halves of his labour-time of six days is called forth. The same applies to the necessary and surplus-labour of the wage-labourer.
The process of production expires in the commodity. The fact that labour-power was expended in its fabrication now appears as a material property of the commodity, as the property of possessing value. The magnitude of this value is measured by the amount of labour expended; the value of a commodity resolves itself into nothing else besides and is not composed of anything else. If I have drawn a straight line of definite length, I have, to start with, "produced" a straight line (true, only symbolically, as I know beforehand)by resort to the art of drawing, which is practised in accordance with certain rules (laws) independent of myself. If I divide this line into three sections (which may correspond to a certain problem), every one of these sections remains a straight line, and the entire line, whose sections they are, does not resolve itself by this division into anything different from a straight line, for instance into some kind of curve. Neither can I divide a line of a given length in such a way that the sum of its parts is greater than the undivided line itself; hence the length of the undivided line is not determined by any arbitrarily fixed lengths of its parts. Vice versa, the relative lengths of these parts are limited from the outset by the size of the line whose parts they are.
In this a commodity produced by a capitalist does not differe in any way from that produced by an independent labourer or by communities of working-people or by slaves. But in the present case the entire product of labour, as well as its entire value, belongs to the capitalist. Like every other producer he has to convert his commodity by sale into money before he can manipulate it further; he must convert it into the form of the universal equivalent.
Let us examine the commodity-product before it is converted into money.
It belongs wholly to the capitalist. On the other hand as a useful product of labour, a use-value, it is entirely the product of a past labour-process.
Not so its value. One portion of this value is but the value of the means of production expended in the production of this commodity and re-appearing in a new form. This value has not been produced during the process of production of this commodity, for the means of production possessed this value before the process of production, independently of it; they entered into this process as the vehicles of this value; it is only its form of appearance that has been renewed and altered. This portion of the value of the commodity constitutes for the capitalist an equivalent of the portion of the constant capital-value advanced and consumed in the production of the commodity.
It existed previously in the form of means of production; it exists now as a component part of the value of the newly produced commodity. As soon as this commodity has been turned into money, the value now existing in the form of money must be reconverted into means of production, into its original form determined by the process of production and its function in it. Nothing is altered in the character of the value of a commodity by the function of this value as capital.
A second portion of the value of a commodity is the value of the labour-power which the wage-worker sells to the capitalist. It is determined, the same as that of the means of production, independently of the process of production into which labour-power is to enter, and it is fixed in an act of circulation, the purchase and sale of labour-power, before the latter enters the process of production. By means of his function -- the expenditure of labour-power -- the wage-labourer produces a commodity-value equal to the value which the capitalist has to pay him for the use of his labour-power. He gives this value to the capitalist in the form of a commodity and is paid for it by him in money. That this portion of the commodity-value is for the capitalist but an equivalent for the variable capital which he has to advance in wages does not alter in any way the fact that it is a commodity-value newly created during the process of production and consisting of nothing but what surplus-value consists of, namely, past expenditure of labour-power.
Nor is this truth affected by the fact that the value of the labour-power paid by the capitalist to the labourer in the form of wages and assumes the form of a revenue for the labourer, and that not only labour-power is continually reproduced thereby but also the class of wage-labourers as such, and thus the basis of the entire capitalist production.
