CONSTANT CAPITAL AND VARIABLE CAPITAL
The various factors of the labor process contribute in varying degrees to the formation of the value of the product.The worker adds new value to the subject matter of his labor by expending upon it a definite amount of additional labor,
no matter what the specific character, the purpose, and the technical quality of his labor may be. On the other hand, the values of the means of production consumed in the labor process reappear as constituents of the value of the product; as, for instance, the values of raw cotton and spindles reappear in the value of yarn.
Thus the value of the means of production is preserved by its transference to the product. This transference takes place during the conversion of the means of production into the product; it occurs during the labor process.
. . . An instrument of production can never transfer more value to a product than the value which it itself loses in the labor process through the destruction of its own use-value. If it had no value to lose, if it were not itself a product of human labor, it could not transfer any value to the product. It would help to create use-value without creating exchange-value.
Of such a kind are all the means of production which are supplied by nature without human aid; the earth, wind, water, unextracted iron ores, timber in the primeval forest, and so on.. . . Let us suppose that a machine is worth £1,000 and that it wears out in 1,000 days. In this case, day by day, one-thousandth of the value of the machine is transferred by it to its daily product.
Though with daily diminishing vitality, the machine continues as a whole to take part in the labor process. We see, then, that one factor of the labor process, a certain means of production, enters as a whole into that process, while entering only in part into the process of creating value. The difference between the labor process and the process of creating value is here reflected in their material factors, inasmuch as the same means of production count in the same process of production, on the one hand, wholly as an element of the labor process, and on the other hand, only to a fractional extent as a factor in the creation of value.
However, an instrument of production may take part as a whole in the creation of value, although it enters bit by bit into the labor process. Let us assume that in the spinning of cotton, for every 115 lbs. of cotton spun, 15 lbs. are waste, producing no yarn, but only "devil's dust." Now, although this 15% of waste is normal, is inseparable from the average elaboration of the cotton, the value of 15 lbs. of raw cotton has to vanish into dust before 100 lbs. of yarn can be made. The perishing of this amount of cotton is, therefore, a necessary condition for the production of the yarn. For that very reason, it gives up its value to the yarn. . . .. . . That part of the capital which is transformed into the means of production, that is to say into raw material, accessory substances, and instruments of labor, does not experience any change in magnitude of value during the process of production. For that reason I speak of it as the constant portion of capital, or, for short, as constant capital. [Contrast this with] the part of capital that is transformed into labor power, undergoes a change of value during the process of production. It reproduces an equivalent for itself, and an excess over and above, a surplus value, which is variable in amount and can be large or smaller. This portion of the capital, from being a constant magnitude, is incessantly changed into a variable magnitude. I therefore speak of this portion of capital as the variable portion of capital, or, for short, as variable capital.
The same constituents of capital which, from the outlook of the labor process, are distinguished as objective and subjective factors, respectively -- as means of production, on the one hand, and labor power, on the other -- are from the standpoint of the process of creating surplus value distinguished as constant capital and variable capital. . . .