72 ON COMPARING COMMODITIES

that we can do is to compare the relation in
which cloth stood at each period to some other
commodity. When we say, that an article in a
former age was of a certain value, we mean,
that it exchanged for a certain quantity of
some other commodity. But this is an inapplicable

 expression in speaking of only one
commodity at two different periods. We cannot
 say, that a pair of stockings in James the
First's reign would exchange for six pair in our
own day; and we therefore cannot say, that a
pair in James the First's reign was equal in
value to six pair now, without reference to
some other article.
Value is a relation between contemporary
commodities, because such only admit of being
exchanged for each other; and if we compare
the value of a commodity at one time with its
value at another, it is only a comparison of the
relation in which it stood at these different
times to some other commodity. It is not a
comparison of some intrinsic, independent quality
 at one period, with the same quality at