Which school of thought argued that land was the source of all wealth?

Physiocracy argued that land, especially agricultural land, was the source of all wealth.

The school emerged in eighteenth-century France among Enlightenment economists including François Quesnay, Victor de Riqueti, Marquis de Mirabeau, and Anne-Robert-Jacques Turgot. Physiocrats divided society into landowners, farmers, and a so-called “sterile” class of artisans and merchants. They believed only agriculture generated a net surplus, while other activities merely transformed or circulated what farming produced.

Quesnay presented these flows in the Tableau économique, first published in 1759. Physiocracy also promoted laissez-faire trade and influenced Adam Smith and later classical economists. A common mix-up is to say physiocrats believed every kind of labor was unproductive; their narrower claim was that only agricultural labor created a net product under their model. Modern economics rejects their exclusive focus on land, recognizing capital, labor, technology, and institutions as sources of production.