or whatever it may be) determines what it will exchange for. The natural tendency is for commodities of equal value to exchange for each other, or for other commodities of equal value.
For example: the amount of wheat produced by ten hours of necessary social labor time will exchange for the amount of cloth, shoes, chairs, gold or some other commodity that will be produced by ten hours of necessary social labor.
The value or values for which commodities will exchange change constantly as the social labor necessary to their production changes. Last month we read of a new molding machine that enables one boy to produce as many castings in one day as four men had been accustomed to produce. These castings have now greatly decreased in value (in the individual plant where the new process is used) but the total value of castings in general has been only slightly reduced. The average labor necessary to produce castings is only a little less than formerly. When the new process becomes general and the average necessary labor greatly reduced, castings will greatly decrease in value.
"If we consider commodities as values, we consider them exclusively under the single aspect of realized, fixed, or, if you like, crystalized human labor. In this respect they can differ only by representing greater or smaller quantities of labor, as for example, a greater amount of labor may be worked up in a silken handkerchief than in a brick.
