In commodities this mystification is as yet very simple. It is more or less plain to everybody that a relation of commodities as exchange values is nothing but a mutual relation between persons in their productive activity. This semblance of simplicity disappears in higher productive relations. All the illusions in regard to the monetary system are due to the fact that money is not regarded as something representing a social relation of production, but as a product of nature endowed with certain properties. The modern economists who sneer at the illusions of the monetary system, betray the same illusion as soon as they have to deal with higher economic forms, as, e. g., capital.6 It breaks forth in their confession of naive surprise, when what they have just thought to have defined with great difficulty as a thing suddenly appears as a social relation and then reappears to tease them again as a thing, before they have barely managed to define it as a social relation.
Since the exchange value of commodities is, in fact, nothing but a mutual relation of the labors of individuals—labors which are similar and universal—nothing but a material expression of a specific social form of labor, it is a tautology to say that labor is the only source of exchange value and consequently of wealth, in so far as the latter consists of exchange values. Similarly, it is a tautology to say that matter in its natural state has no exchange value, because it does not contain any labor, and that exchange value as such does not contain matter. But when William Petty calls “labor the father and earth the mother of wealth,” or when Bishop Berkeley asks “whether the four elements and man’s labour therein, be not the true source of wealth,”7 or when the American, Thomas Cooper puts it popularly: “Take away from a piece of bread the labour bestowed by the baker on the flour, by the miller on the grain brought to him, by the farmer in ploughing, sowing, tending, gathering, threshing, cleaning and transporting the seed, and what will remain? A few grains of grass, growing wild in the woods, and unfit for any human purpose”8—then all these views do not refer to abstract labor as the source of exchange value, but to concrete labor as the source of