 Mersenne’s dealings with Descartes were only a small part of the network of intellectual communication that he built up throughout his career. He was largely responsible for introducing Galileo into France, offering in 1630—without receiving an answer—to publish his future work on the Two Chief Systems of the World. In 1634, he published Les Méchaniques de Galilée, a free translation of a manuscript on mechanics by the Florentine scholar, completed with ideas borrowed from Guidobaldo and Stevin, and with original comments of his own, and, in 1639, the Nouvelles pensées de Galilée, a translation or adaptation of certain parts of the Discorsi a due nuove scienze, published in Italy one year earlier. Mersenne was also in regular contact with English scholars. He translated into French the De Veritate of Herbert of Cherbury (although the book had been placed in the Index, i.e., the list of prohibited books published by the Catholic Church); in good terms with Hobbes (Baldin 2020), he published one of his optical treatises, and Sorbière’s French translation of the De Cive. He corresponded with Kenelm Digby and Lord Cavendish and others.