But his conquest of Germany was equally startling and momentous. The movement in that country can be directly traced to the university of Königsberg, where Kraus began to lecture on the _Wealth of Nations_ in 1781. He soon gained the ears of the official class. In East Prussia, vexatious dues and taxes, with a multitude of feudal embarrassments, were removed from internal commerce, and in spite of much opposition Smith’s principles spread all over Germany. By the close of the Napoleonic war the officials as well as the professional economists were converts to the new ideas. Stein and Hardenberg, two truly great reformers, led the way. Year by year commercial restrictions were removed, and though jealousy of Prussia stood in the way of complete commercial union, the North German Zollverein constituted a great advance. It removed the barriers between Prussia and the adjoining States, and reduced external duties to such an extent that in 1827 Huskisson cited the example set by Germany to prove the wisdom of abandoning a restrictive policy. Even Friedrich List, who sought for political reasons to build up a counter theory of protection for infant industries, asserted that free trade was the right policy for England and for every adult nation. List, who often wrote with a bitterness and malice that only readers of his unhappy life can excuse, admitted in his principal work “the great services of Adam Smith”:— “He was the first to introduce successfully into political economy the analytical method. By means of this method and of an unusual sharpness of intellectual vision he illuminated the most important branches of a science, which before his time had lain in almost utter darkness. Before Adam Smith there was only a policy (Praxis); his labours first made it possible to build up a science of political economy; and for that achievement he has given the world a greater mass of materials than all his predecessors and successors.”