178 A MEASURE AND A CAUSE OF VALUE.

tion of 2 commodity in which a definite portion
 of it was embodied *.

All that is really meant by a measure of
value we have already seen, and what is implied
 by a cause of value will be examined in
the following chapter. The object of the preceding
 brief discussion is not to consider the
nature of either, but merely to show the essential
 distinction between the ideas which they
involve.

* There was a further reason, namely, that the real object
which he contemplated in a measure of value was to ascertain
 by it the changes which commodities wight undergo
in regard to the quantity of labour required to produce
them. Now to use labour itself as a measure implies this
object to be already accomplished. Sce Note I.