Wicked Company is a group biography of the philosophes, whose courageous and radical thought helped prepare France for the seismic political upheaval of 1789. Philipp Blom deftly delineates the friendship through which Denis Diderot and the Baron d’Holbach pursued philosophical truth and collaborated on the eighteenth century’s most ambitious publishing project: the Encyclopédie, ou dictionnaire raisonné des sciences, des arts et des métiers (which ran to twenty-eight volumes between 1751 and 1772, covering topics as diverse as azymites and tailoring). The aim of the Encyclopédie’s editors was ‘to collect all the knowledge that now lies scattered over the face of the earth, to make known its general structure to the men among whom we live, and to transmit it to those who will come after us’ – to make men not only wiser but also ‘more virtuous and more happy’. The relations of both Diderot and d’Holbach to Voltaire and Rousseau (whose posthumous reputations have fared somewhat better in the Anglophone world) are also carefully drawn; as are their connections with foreign writers and intellectuals (Friedrich Grimm, David Hume, Ferdinando Galiani and Count Beccaria) and their interactions with rare examples of freethinking women, the brilliant and wealthy Louise d’Epinay especially.

Denis Diderot was born in 1713 in the small town of Langres in northern Champagne. He was sent to Paris, aged fifteen, to complete his education and train for the priesthood, but rebelled and decided to become a playwright instead: ‘What did I have in mind? To be