Condorcet is undoubtedly the most economically minded philosopher of the Enlightenment.

For a large part of his career, he devoted himself to fields entirely unrelated to economics, and rightly so, as his talents led to great progress in the sciences he focused on most. But around 1770, he felt drawn to economic questions, perhaps because other philosophers, especially Voltaire and Diderot, did not bother to dedicate their leisure time to them, and also because he had befriended Turgot.

Condorcet gradually embraced ideas of laissez-faire and liberty, initially in areas unrelated to political economy. In his Letter of a Theologian, he philosophically mocked the Catholic religion and expressed his wish to see genuine freedom of belief, including freedom not to believe. In his crusade for tolerance and against religious fanaticism, Condorcet fought for the rehabilitation of the Chevalier de la Barre and for the retrial of D'Etallonde, who had been sentenced to death for breaking a crucifix.

He was thus prepared to defend liberty when his friend Turgot rose to the position of Controller-General of Finances.

From then on, Condorcet's career took a turn as he entered the economic debate, tirelessly supporting the liberal reforms of the new minister. Favoring competition and freedom of commerce, Condorcet also called for the abolition of corvées (forced labor), guilds, and for fair taxation. He voiced these convictions publicly whenever opportunity arose, doing so with obvious enthusiasm; he wrote extensively and once declared in his writings: "Allow me to speak again of the freedom of commerce; I enjoy engaging with this subject."

Between 1774 and 1776, during Turgot's ministry, Condorcet made numerous interventions, all marked by his commitment to laissez-faire. His works include Letters from a Farmer of Picardy to Mr. Necker, defending free trade; Monopolies and Monopolists, advocating free competition; Reflections on Corvées, calling for their abolition; and Reflections on the Grain Trade, which again praises free trade and critiques Necker's book on the same subject.

In his Letters on the Grain Trade, Condorcet makes several key points.

First, the high grain prices at the time were not the result of free trade, but rather of poor harvests, and Condorcet demonstrates this clearly. He then explains why laissez-faire is not only appropriate but the only suitable policy, despite popular prejudice. He notes, "We are so used to seeing the government intervene in the grain trade that doing nothing seems like something extraordinary and new". Later, he adds, "Almost everyone, especially those holding public office, believe that nothing happens on its own and that everything is lost if the government doesn't intervene in everything". Condorcet thus revives the arguments of the Physiocrats and Turgot, showing the superiority of free trade over all forms of interventionism.

Promoting Turgot's liberal economic agenda was a courageous act, as Condorcet knew he would quickly face censorship. Indeed, this happened and his pamphlet on the abolition of forced labor was destroyed and banned in 1776.

Turgot, appreciating Condorcet's loyal defense of his ideas, appointed him Inspector of Coinage. Condorcet resigned as soon as his friend left the ministry.

Although he devoted all his energy to defending Turgot, Condorcet had no illusions about the outcome of his friend's tenure. Turgot himself admitted late in life that he lived with regret, as he wrote in a letter, "for not having been able to do my nation and humanity a good I believed very easy". Condorcet, more realistic, pointed out the many adversaries Turgot would face: the king's favorites, the parliaments, the clergy, the nobility, the guilds, and so on. These groups expected flattery, not reform. Condorcet told Turgot, "You are by no means a charlatan, and that is a flaw, given how things are in Paris". He was perfectly right, for in 1776, barely two years after his arrival, Turgot was already forced to leave the Controller-Generalship.