William Cunningham, The Progress of Economic Doctrine in England in the Eighteenth Century (1891)
“ National prosperity and relative superiority were vague and difiicult notions, but when the whole discussion was made to turn on wealth, the treatment seemed to be more concrete and definite, and it took hold upon the public mind. There were of course some economists who never really adapted their habits of thought in accordance with Adam Smith's principles. Playfair speaks of him with respect, but he continued to draw his beautiful diagrams of the Balance of Trade, as if he still thought it furnished a criterion of something. ”
