corn regulates the prices of all commodities, is at once to erect it
into a standard measure of real value in exchange; and we must
either deny the truth of Dr Smith's argument, or acknowledge, that
what seems to be quite impossible is found to exist; and that a
given quantity of corn, notwithstanding the fluctuations to which
its supply and demand must be subject, and the fluctuations to which
the supply and demand of all the other commodities with which it is
compared must also be subject, will, on the average of a few years,
at all times and in all countries, purchase the same quantity of
labour and of the necessaries and conveniences of life.

There are two obvious truths in political economy, which have not
infrequently been the sources of error.

It is undoubtedly true, that corn might be just as successfully
cultivated, and as much capital might be laid out upon the land, at
the price of twenty shillings a quarter, as at the price of one
hundred shillings, provided that every commodity, both at home and
abroad, were precisely proportioned to the reduced scale. In the
same manner as it is strictly true, that the industry and capital of
a nation would be exactly the same (with the slight exception at
least of plate), if, in every exchange, both at home or abroad, one
shilling only were used, where five are used now.

But to infer, from these truths, that any natural or artificial
causes, which should raise or lower the values of corn or silver,
might be considered as matters of indifference, would be an error of
the most serious magnitude. Practically, no material change can take
place in the value of either, without producing both lasting and
temporary effects, which have a most powerful influence on the