Epicurean and Galilean Motion in Gassendi's Physics



Pierre Gassendi held a Galilean theory of the motion of composite bodies. He also accepted an Epicurean theory of the motion of atoms according to which atoms can never gain or lose speed. The conjunction of these two theories is awkward and, from the point of view of physics, unfruitful. I offer metaphysical reasons why Gassendi might have thought he needed to adopt the Epicurean view of atomic motion.