François Quesnay was an 18th-century French economist and physician, best known as the founder of the Physiocratic school of thought. He emphasized the importance of agriculture as the primary source of wealth and believed that land was the foundation of economic prosperity. His ideas challenged the mercantilist views of his time. Quesnay is also recognized for his work on the Tableau Économique, a diagram that illustrated the flow of goods and money in an economy. This innovative approach laid the groundwork for modern economic theory and influenced later economists, including Adam Smith.