"The things which have the greatest value in use have frequently little or no value in exchange; on the contrary, those which have the greatest value in exchang

"The things which have the greatest value in use have frequently little or no value in exchange; on the contrary, those which have the greatest value in exchange have frequently little or no value in use. Nothing is more useful than water: but it will purchase scarcely anything; scarcely anything can be had in exchange for it. A diamond, on the contrary, has scarcely any use-value; but a very great quantity of other goods may frequently be had in exchange for it." -Adam Smith , from An Inquiry into the Nature and Causes of the Wealth of Nations