It is obvious that if A spends six hours in the production of iron and six hours on linen, and B also produces iron during six hours and linen during another six hours, it is but a different application of _the same_ labor time that would be expended, if A produced iron during twelve hours, while B worked twelve hours on linen. But how about skilled labor which rises above the level of average labor by its higher intensity, by its greater specific gravity? This kind of labor resolves itself into unskilled labor composing it; it is simple labor of a higher intensity, so that one day of skilled labor, e. g., may equal three days of unskilled labor. This is not the place to consider the laws regulating this reduction. It is clear, however, that such reduction does take place, for, as exchange value, the product of the most skilled labor is, when taken in a certain proportion, equivalent to the product of unskilled average labor, or equal to a definite quantity of that unskilled labor. The determination of exchange-value by means of labor-time implies, further, the fact that an equal quantity of labor is embodied in any given commodity, e. g., a ton of iron, no matter whether it is the work of A or B, that is to say, various individuals expend an equal amount of labor-time for the production of the same use-value of a given quality and quantity. It is thus assumed that the labor-time contained in a commodity is the labor-time _necessary_ for its production, i. e., it is the labor-time which is required for the production of another specimen of the same commodity under the same general conditions of production. The conditions of labor, which creates exchange value, as shown by the analysis of the latter, are _social conditions_ of labor or conditions of _social labor_. Social, not in the ordinary, but in a special sense. It is a specific form of the social process. The homogeneous simplicity of labor means first of all _equality_ of the labors of various individuals, a reciprocal relation of equality of their labors determined by the actual reduction of all kinds of labor to uniform labor. The labor of every individual, as far as it is expressed in exchange value possesses this social character of equality and finds expression in exchange value only in so far as it is a relation of equality with the labor of all other individuals.