Denis Diderot

Diderot was the son of a cutler from Langres, educated by the Jesuits and at the University of Paris. With his master of arts in hand he refused to become priest or lawyer and lived ten bohemian years in Paris on translations and tutoring, married secretly, was locked in a monastery by his father and climbed out over the wall. In 1746 the Philosophical Thoughts were ordered burned by the parlement, and in 1749 the Letter on the Blind, with its atheist leanings, put him in the prison of Vincennes for three months; it was on the walk to visit him that Rousseau had his epiphany.

In 1747 he took over a project that had begun as a mere translation of an English encyclopaedia and turned it into the collective manifesto of the Enlightenment. The Encyclopédie ran to seventeen volumes of text and eleven of plates with over one hundred and forty contributors, appearing between 1751 and 1772; it was banned twice, d'Alembert quit, the publisher secretly censored it, and Diderot alone saw it through, writing thousands of articles himself, above all on crafts and trades, placing the knowledge of artisans beside that of scholars for the first time.

His most radical works were unpublished in his lifetime: D'Alembert's Dream imagines matter as sensitive and species as evolving; Rameau's Nephew lets a parasitic genius strip the hypocrisy from every morality, and Goethe translated it and Hegel quoted it in the Phenomenology of Spirit; Jacques the Fatalist is a novel about freedom and necessity. In 1773 he visited Catherine the Great in St Petersburg; she had bought his library and made him its salaried librarian, in effect a pension. He said his readers would be found in the twentieth century.