But corn is a commodity, as well as gold, silver, and other things; if all commodities, therefore, have a high exchangeable value in a rich country, corn must not be excepted; and hence we might correctly say, that corn exchanged for a great deal of money, because it was dear, and that money too exchanged for a great deal of corn, because that also was dear; which is to assert that corn is dear and cheap at the same time. No point in political economy can be better established, than that a rich country is prevented from increasing in population, in the same ratio as a poor country, by the progressive difficulty of providing food. That difficulty must necessarily raise the relative price of food, and give encouragement to its importation. How then can money, or gold and silver, exchange for more corn in rich, than in poor countries? It is only in rich countries, where corn is dear, that landholders induce the legislature to prohibit the importation of corn. Who ever heard of a law to prevent the importation of raw produce in America or Poland?--Nature has effectually precluded its importation by the comparative facility of its production in those countries. How then can it be true, that "if you except corn, and such other vegetables, as are raised altogether by human industry, all other sorts of rude produce--cattle, poultry, game of all kinds, the useful fossils and minerals of the earth, &c., naturally grow dearer as the society advances." Why should corn and vegetables alone be excepted? Dr. Smith's error throughout his whole work, lies in supposing that the value of corn is constant; that though the value of all other things may, the value of corn never can be raised. Corn, according to him, is always of the same value, because it will always feed the same number of people. In the same manner it might be said, that cloth is always of the same value, because it will always make the same number of coats. What can value have to do with the power of feeding and clothing?