The French school of economics, led by physician and economist Francois Quesnay (1694-1774), whose theory maintained that a natural order existed and it was the duty of the state to preserve this order.
The Physiocrats believed that land was the only source of wealth and, therefore, agriculture was the only sector that should be taxed. Industry and commerce should be excluded from state intervention, giving rise to their policy of laissez-faire which was in direct opposition to mercantilism.
F Quesnay, Tableau e'conomique (Paris, 1758);
R L Meek, The Economics of Physiocracy: Essays and Translations (London, 1962)