Thus the continuous purchase and sale of labour-power perpetuates on the one hand labour-power as an element of capital, by virtue of which the latter appears as the creator of commodities, articles of use having value, by virtue of which, furthermore, that portion of capital which buys labour-power is continually restored by labour-power’s own product, and consequently the labourer himself constantly creates the fund of capital out of which he is paid. On the other hand the constant sale of labour-power becomes the source, ever renewing itself, of the maintenance of the labourer and hence his labour-power appears as that faculty through which he secures the revenue by which he lives. Revenue in this case signifies nothing else than a appropriation of values effected by ever repeated sales of a commodity (labour-power), these values serving only for the continual reproduction of the commodity to be sold. And to this extent Smith is right when he says that the portion of the value of the product created by the labourer himself for which the capitalist pays him an equivalent in the form of wages, becomes the source of revenue for the labourer. But this does not alter the nature or magnitude of this portion of the value of the commodity any more than the value of the means of production is changed by the fact that they function as capital-values, or the nature and magnitude of a straight line are changed by the fact that it serves as the base of some triangle or as the diameter of some ellipse. The value of labour-power remains quite as independently definite as that of those means of production. This portion of the value of a commodity neither consists of revenue as an independent factor constituting this value-part nor does it resolve itself into revenue. While this new value constantly reproduced by the labourer constitutes a source of revenue for him, his revenue conversely is not a constituent of the new value produced by him. The magnitude of the share paid to him of the new value created by him determines the value-magnitude of his revenue, not vice versa. The fact that this part of the newly created value forms a revenue for him, indicates merely what becomes of it, shows the character of its application, and has no more to do with its formation than with that of any other value. If my receipts are ten shillings a week that changes nothing in the nature of the value of the ten shillings, nor in the magnitude of their value. As in the case of every other commodity so in that of labour-power its value is determined by the amount of this labour is necessary for its reproduction; that the amount of this labour is determined by the value of the labourer’s necessary means of subsistence, hence is equal to the labour required for the reproduction of the very conditions of his life — that is peculiar for this commodity (labour-power), but no more peculiar than the fact that the value of labouring cattle is determined by the value of the means of subsistence necessary for its maintenance, i.e., by the amount of human labour necessary to produce these means of subsistence.