As we saw in the first of the three chapters devoted to the Physiocrats, Quesnay's followers were all the rage in France for about a decade. This enthusiasm for their ideas took shape both in their time and continued until the end of the century. Here, we will look at some of their achievements and the influence they exerted on their successors in the field of economic thought.

Their greatest accomplishment, following the Gournay group, was to popularize economic ideas. Voltaire's famous saying is well known: around 1750, the nation, satiated with poetry and novels, began to reason about grain. The Physiocrats took part in this movement, publishing literally hundreds of articles, pamphlets, and books about the freedom of the grain trade. The strong momentum given by the Physiocrats to economic discussions is also evident in the impressive number of economic works and pamphlets published in France from 1760 to 1775. As further evidence of the spread of economic ideas in France, one recalls the remark by M. de Vaublanc, cited in a previous lecture, who said in Metz in 1774 that people spoke of nothing but economics. "It was the fashion", he said. "Everyone was an economist".

The defense of their ideas, in books, pamphlets, and in their journal Les Éphémérides du Citoyen, quickly had repercussions in France's economic policy. In 1763, an edict granted freedom of the grain trade, which Quesnay and Mirabeau had strongly demanded. On several occasions, authorities also eased the regulations governing trade guilds to guarantee greater freedom to work.

Abroad, success came very early. In Germany, the Margrave of Baden took an interest in physiocratic ideas and maintained a regular correspondence with Mirabeau and Dupont de Nemours.

He tasked the economist Johann August Schlettwein, a convinced physiocrat, with implementing a tax reform and liberalize the grain trade. In April 1770, a first trial took place in the small village of Dietlingen. The villagers seemed to have welcomed the measures enthusiastically, but the officials in charge were not very supportive, which delayed the wider implementation.

In Russia, Catherine II was preparing a legislative reform and asked Diderot to send her a brilliant mind to assist her.

Impressed by the reading of The Natural and Essential Order of Political Societies, published in 1767, he sent her its author, the physiocrat Mercier de la Rivière.

Although he left France celebrated, his reception in Saint Petersburg was cool (climate aside), and the Empress was disappointed in him.

In Sweden, with Gustav III, and in Italy, with Leopold of Tuscany, the Physiocrats also found followers ready to put their ideas into practice.

In France, the Physiocrats enjoyed spectacular success with the appointment of Turgot as Controller-General of Finances in 1774.

Conscious of the decline in their fame, Turgot never presented himself as a loyal disciple of the Physiocrats, nor, for that matter, as an encyclopedist, although he was one, and since they were despised by the members of the Clergy. Once in power, Turgot issued six famous edicts that constituted the beginning of a practical application of the Physiocratic program: freedom of commerce, freedom of labor, and the end of monopolies.

By the time of the French Revolution, the Physiocrats had fewer followers. The marquis of Mirabeau died on July 13, 1789—quite a symbol. Abeille had moved on, but Dupont de Nemours remained faithful. Appointed to the Assembly, Dupont de Nemours carried the voice of Physiocracy and called for economic reforms in favor of property ownership and free trade.

He also fought, unsuccessfully, against the assignats. Despite this failure, Physiocratic thought remained very present in the intellectual debate and influenced the early achievements of the Revolution. As Joseph Rambaud said, everything the Revolution did in favor of liberties was due to the Physiocrats.

The Physiocrats also had a major influence on the history of economic thought. Adam Smith, who visited France and met many of them, was deeply influenced by their work. He even considered dedicating The Wealth of Nations to Quesnay.

Sadly, Quesnay died two years before Smith's book was published, and Smith removed the dedication. Although Smith didn't agree with their idea that only agriculture was productive, he embraced many of their arguments for free markets and carried them forward in his own work.