Hobbes surely spent the ten years (1641–1651) of greatest significance for his philosophical career on the Continent, in France, above all, in Paris. It was during this period that he published De cive; wrote the De motu, loco et tempore; produced a draft of the entire Leviathan as well as most of De corpore. His complicated relationship with Descartes has been studied closely, and Mersenne’s role has become clearer. There remains however the task of more carefully delineating the contours of Hobbes’s relations with the circles of “learned libertinism.” The Libertinism which will be dealt with here was not only French, instead of English, but also “theoretical” and “intellectual” rather than practical, and nothing at all sexual, contrary to the common usage of that word in the current language. French Libertinism was a philosophical trend aimed at promoting a non-conformist approach to religion, history, morals, and even politics.