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
