Charles Davenant was one of the leading economic pamphleteers of the 1690s. He frequently developed general principles, some of which sound almost like the early writings of Adam Smith. He was, however, a Mercantilist in the sense that he underlined the advantages of a favourable balance of trade as a source of political power, favoured population growth and decried luxury spending. William Petty focused on some practical questions of his times including war finance, monetary reform, relief for the poor. His work contains a veritable cornucopia of terms and concepts that came to dominate economic thinking for the next three centuries; 'full employment' and 'ceteris paribus', the idea of national income as identical to national expenditure, public works as a method of dealing with unemployment etc. However his greatest contribution was the invention of what he called 'political arithmetic', the quantitative estimation of both the stock of national wealth and the flow of national income to determine the appropriate base for taxation.