By the early 17th century there was a good deal of interest and concern with Epicurean physics, especially among chemists and medical doctors, and some interest and concern with Epicurean moral theory and theology. People who were sceptical of traditional morality and theology were being accused by fanatics like le père Garasse of being Epicureans, even if their professed views were fideistic (like those of Pierre Charron).¹ In this paper I will not attempt to survey the various writers of Epicurean tendencies of the period, their affinities to scepticism, and the accusations made against them. Instead I shall treat just two figures, Pierre Gassendi and Uriel Da Costa, and shall try to show that each of them tried to combine an aspect of Epicureanism with a type of scepticism - Gassendi joining an epistemological scepticism with Epicurean physics, and Da Costa joining a religious scepticism with portions of Epicurean theology. The later fusion of these two views produced, I believe, the modern scientific unbeliever.