Baptized the "Rousseau of the nineteenth century", Pierre Leroux (1797-1871) invented the word "socialism" and was a source of inspiration for a vast group of writers, including Proudhon, Blanqui, Baudelaire, Heine, Renan, Durkheim and Marx, who in 1843 did not hesitate to describe it as "great". It is that prior to Marx and Engels, Leroux had already solidly initiated the criticism of the Christian religion and English political economy, as ancient ways of conceiving humanity. Forgotten by the various socialist orthodoxies, in the writings of this "Thinker of humanity" - as was also characterized -, is distilled in an original way, a theory that combines a primitive communism with the utopia of a libertarian society. In these reflections addressed to philosophers, artists and politicians, Leroux places modern freedom as the nucleus of a new synthesis of humanity, in which equality will finally encompass the working class and women. A mystical and feminist socialism that places the question of emancipation as an act at once philosophical, political, economic, religious and aesthetic. It is through these texts -as Miguel Abensour has pointed out- of returning to the question of emancipation, not to abandon it but to complicate it.