The physiocrats, a group of economists whose period of greatest activity was between 1756 and 1774, the year of the death of Francois Quesnay, master of the group, had a short life as a school. The birth of the school can be traced to the meeting of the two founders, Francois Quesnay and the Marquis de Mirabeau, in July 1757. But 2 years before, in 1755, an event of the greatest importance had taken place: the publishing, some 25 years after its writing, of the mast of Richard Cantillon Essai sur la nature du commerce en général. Cantillon's work has been defined as the first complete treatise on political economy, but it also contributed to the birth of physiocracy, the first school. So our history must begin with this the contribution.