The Wealth of Nations by Part 1 Chapter 11 Page 248

If the complete improvement and cultivation of the country be, as it most certainly is, the greatest of all public advantages, this rise in the price of all those different sorts of rude produce, instead of being considered as a public calamity, ought to be regarded as the necessary forerunner and attendant of the greatest of all public advantages.

This rise, too, in the nominal or money-price of all those different sorts of rude produce has been the effect, not of any degradation in the value of silver, but of a rise in their real price. They have become worth, not only a greater quantity of silver, but a greater quantity of labour and subsistence than before. As it costs a greater quantity of labour and subsistence to bring them to market, so when they are brought thither, they represent or are equivalent to a greater quantity.