Section 3: The Form of Value or Exchange Value

The purpose of section 3 is to trace the "genesis" of money, from exchange value to "the dazzling money-form."

In all subsections, a value relation is any relation that manages to express, or reveal, the value of a single commodity.

A. Elementary or Accidental Form Of Value

x commodity A = y commodity B

The left side of the equation is the relative form, the commodity that has its value expressed. The right side of the equation is the equivalent form, the commodity that expresses value by acting as an equivalent.

This elementary form of value is symmetrical, so reading it either direction is equally valid and merely a different perspective; but in either case, only one or the other commodity expresses its value.

The equation implies equivalence of both quantity and quality. The word for this ability to compare quantity, by virtue of identical quality, is commensurability. The value of the relative-form commodity takes on an existence in the bodily form, in the use value, of the equivalent-form commodity. This sounds really odd, but think of it like mentally substituting "y commodity B" everywhere you see "x commodity A", not just in quantity, but in quality too. The physical body of commodity B gives a physical, independent existence for the purely social value-substance from our analysis which is imprisoned inside the use value of commodity A.

Think about the consequence of value taking on the physical form of the equivalent-form commodity (the coat in Marx's example). If the physical body of a commodity is value itself, in the context of a single elementary value relation, can you guess what commodity might be universally recognized as value?

Finally, because value relations are relative, they do not tell us the absolute amount of value in a commodity. If commodities A and B both dropped in value by half, they would still happily exchange at a rate of x to y respectively.