OF VALUE.

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proposed, not only as the cause but the measure
of value, that which is itself unascertainable.
There are only two possible methods of comparing
 one quantity of labour with another;
one is to compare them by the time expended,
the other by the result produced. The former
is applicable to all kinds of [abour; the latter
can be used only in comparing labour bestowed
on similar articles. If therefore, in estimating
two different sorts of work, the time spent will
not determine the proportion between the
quantities of labour, it must remain undetermined
 and undeterminable.
2. We are furnished with cases of the second
kind (namely, those in which two commodities,
once equal in value, have become unequal in
value without any change in the quantity of labour
 respectively employed in aech) by Mr. Ricardo
 himself.
Take any two commodities of equal value,
a and B, one produced by fixed capital and the
other by labour, without the intervention of machinery
 ; and suppose, that without any change