which creates exchange value, is, finally, characterized by the fact that even the social relations of men appear in the reversed form of a social relation of things. Only in so far as two use-values are in a mutual relation of exchange values does the labor of different persons possess the common property of being identical universal labor. Hence, if it be correct to say that exchange value is a relation between persons,5 it must be added that it is a relation disguised under a material cover. Just as a pound of iron and a pound of gold represent the same weight in spite of their different physical and chemical properties, so do two use-values, as commodities containing the same quantity of labor-time, represent the same exchange value. Exchange value thus appears as the natural social destination of use-values, a property which they possess by virtue of being things and in consequence of which they are exchanged for one another in definite proportions, or form equivalents, just as chemical elements combine in certain proportions, forming chemical equivalents. It is only through the habit of everyday life that we come to think it perfectly plain and commonplace, that a social relation of production should take on the form of a thing, so that the relation of persons in their work appears in the form of a mutual relation between things, and between things and persons.
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 material wealth; in short, to labor in so far as it produces use-values. In assuming that a commodity has use-value we assume the special usefulness and distinct fitness of the labor absorbed by it, but that is all there is to the view of labor as useful labor from the standpoint of commodity. Considering bread as a use-value, we are interested in its properties as an article of food and not at all in the different kinds of labor of the farmer, miller, baker, etc. If by some invention nineteen-twentieths of this labor could be saved, the loaf of bread would still render the same service as before. If it fell ready-made from the sky it would not lose a single atom of its use-value. While labor which creates exchange value is realized in the equality of commodities as universal equivalents, labor as a productive activity with a useful purpose is realized in the endless variety of use-values created by it. While labor which creates exchange values is abstract, universal and homogeneous, labor which produces use-values is concrete and special and is made up of an endless variety of kinds of labor according to the way in which and the material to which it is applied.
It is wrong to speak of labor in so far as it is applied to the production of use-values as of the only source of wealth, namely, the material wealth produced by it. Being an activity intended to adapt materials to this or that purpose, it requires matter as a pre-requisite. In different use-values the proportion between labor and raw material varies greatly, but use-value always has a natural substratum. Labor, as an activity, directed to the adaptation of raw material in one form or another, is a natural condition of human existence, a condition of exchange of matter between man and nature, independent of all social forms. On the contrary, labor producing exchange value is a specifically social form of labor. Tailoring, e.g., in its material manifestation as a distinct productive activity, produces a coat, but not the exchange value of the coat. The latter is produced not by the labor of the tailor as such, but by abstract universal labor, and that belongs to a certain organization of society which has not been brought about by the tailor. Thus, the women under the ancient system of house industry made coats without producing the exchange value of the coats. Labor as a source of material wealth was known to Moses, the legislator, as well as to Adam Smith, the customs official.9
Let us consider now some propositions which follow from the determination of exchange value by labor-time.
As a use-value, every commodity owes its usefulness to itself. Wheat, e.g., serves as an article of food. A machine saves labor to a certain extent. This function of a commodity by virtue of which it serves only as use-value, as an article of consumption, may be called its service, the service which it renders as use-value. But as an exchange value, a commodity is always regarded as a result; the question in this case is not as to the service which it renders, but as to the service10 which it has been rendered in its production. Thus, the exchange value of a machine is determined not by the quantity of labor-time which it saves, but by the quantity of labor-time which has been expended on its own production and which is, therefore, required to produce a new machine of the same kind.
If, therefore, the quantity of labor-time required for the production of commodities remained constant, their exchange value would remain the same. But the ease and the difficulty of production are constantly changing. If the productivity of labor increases, the same use-value will be produced in less time. If the productivity of labor declines, more time will be required for the production of the same use-value. Thus, the labor-time contained in a commodity or its exchange-value is a variable quantity, increasing or diminishing in an inverse ratio to the rise and fall of the productivity of labor. The productive power of labor which is applied in the manufacturing industry on a predetermined scale depends in the agricultural and extractive industries also on natural conditions which are beyond human control. The same labor will yield a greater or less output of various metals, according to their more or less close occurrence in the earth’s crust. The same labor may be embodied in two bushels of wheat in a favorable season, and only in one in an unfavorable season. In this case, scarcity or abundance, as natural conditions, seem to determine the exchange value of commodities, because they determine the productivity of certain kinds of labor which depend upon natural conditions.
Unequal volumes of different use-value contain the same quantity of labor-time or the same exchange value. The smaller the volume of a use-value containing a certain quantity of labor-time as compared with other use-values, the greater its specific exchange-value. If we find that certain use-values, such as, e.g., gold, silver, copper and iron, or wheat, rye, barley and oats, form a series of specific exchange values which, though not retaining exactly the same numerical ratio, still retain through widely remote epochs of civilization the same rough proportion of relatively larger and smaller quantities, we may draw the conclusion that the progressive development of the productive powers of society has equally, or approximately so, affected the labor-time necessary for the production of the various commodities.
The exchange value of a commodity is not revealed in its own use-value. But, as the embodiment universal social labor-time, the use-value of one commodity bears a certain ratio to the use-values of other commodities. Thus, the exchange value of one commodity is manifested in the use-values of other commodities.