Until the Age of Enlightenment, utopia was a literary genre without concrete political effects. However, in France, in the decades leading up to 1789, its status gradually changed. The ideal of a community of property and labour, not yet called communism, was taken more seriously by some thinkers: first Étienne-Gabriel Morelly, a fierce critic of private property and the mysterious author of the Code de la Nature; then the Abbé de Mably, a radical republican and interlocutor of Rousseau; finally, Babeuf, who, from the 1780s onwards, defended the natural right to subsistence and dreamed of a more fraternal world. In the crucible of the French Revolution, "real equality" became the goal of a handful of conspirators gathered around Babeuf, who had meanwhile become the "tribune of the people." Together, they laid the foundations for modern socialist movements. This book traces the steps that led to this great invention.