Pierre Gassendi has been widely credited with two major contributions to seventeenth century natural philosophy: The first is the revival of the tradition of classical atomism associated with Democritus, Epicurus, and the Roman poet Lucretius, which had wide influence and appeal among the mechanical philosophers.1 It is clear, for instance, that Robert Boyle was familiar with his works and influenced by his corpuscular philosophy, and there is also evidence that Gassendi’s corpuscular system had a significant influence on Newton’s early philosophy.2 The second major contribution was his programmatic promotion of nominalist epistemology and ontology, which reinforced his empirical/mechanical philosophical system. Gassendi has also been noted as a source of the theological voluntarism that was particularly popular in seventeenth century England, and his voluntarist conceptions have a firm basis in his ontology.3