purely out of self-interest and greed, and warns that, ...[a]ll for ourselves, and nothing for other people, seems, in every age of the world, to have been the vile maxim of the masters of mankind. Book IV: Of Systems of political Economy Smith vigorously attacked the antiquated government restrictions he thought hindered industrial expansion. In fact, he attacked most forms of government interference in the economic process, including tariffs, arguing that this creates inefficiency and high prices in the long run. It is believed that this theory influenced government legislation in later years, especially during the 19th century. Smith advocated a government that was active in sectors other than the economy. He advocated public education for poor adults, a judiciary, and a standing army—institutional systems not directly profitable for private industries. Of the Principle of the Commercial or Mercantile System: The book has sometimes been described as a critique of mercantilism and a synthesis of the emerging economic thinking of Smith's time. Specifically, The Wealth of Nations attacks, inter alia, two major tenets of mercantilism: The idea that protectionist tariffs serve the economic interests of a nation (or indeed any purpose whatsoever) and The idea that large reserves of gold bullion or other precious metals are necessary for a country's economic success. This critique of mercantilism was later used by David Ricardo when he laid out his Theory of Comparative Advantage. Of Restraints upon the Importation: Chapter 2's full title is "Of Restraints upon the Importation from Foreign Countries of such Goods as can be Produced at Home". The "invisible hand" is a frequently referenced theme from the book, although it is specifically mentioned only once. The metaphor of the "invisible hand" has been widely used out of context. In the passage above Smith is referring to "the support of domestic industry" and contrasting that support with the importation of goods. Neoclassical economic theory has expanded the metaphor beyond the domestic/foreign manufacture argument to encompass nearly all aspects of economics. Of the extraordinary Restraints: Chapter 3's long title is "Of the extraordinary Restraints upon the Importation of Goods of almost all Kinds, from those Countries with which the Balance is supposed to be Disadvantageous". Of Drawbacks: Merchants and manufacturers are not contented with the monopoly of the home market, but desire likewise the most extensive foreign sale for their goods. Their country has no jurisdiction in foreign nations, and therefore