OF VALUE.

17

this must be owing not only to causes operating
on A, but also to causes operating on B. The
fact of a pound of gold exchanging for fifteen
times the quantity of corn that can be obtained
for a pound of silver, cannot be referred to
causes operating on the corn, but to a difference
in the causes operating on gold and silver.
Hence, how constant or uniform soever a cause
affecting one commodity may be, it cannot
make that object of constant value, without the
concurrence of other invariable causes acting
upon the commodity with which it is compared.

It is precisely this essential circumstance,
which has escaped the notice of Mr. Ricardo.
When he asserts, that a commodity would be of
invariable value, if it were always produced by
the same quantity of labour, he overlooks one
half of the causes concerned in the determination
of value; for a moment's consideration will
teach us, that such a commodity could be of
invariable value, in relation to those commodi-
ties alone, of which the producing labour had
also remained a constant quantity. Not ad-