  It is widely believed that Descartes did not have a response to this objection, indeed that he blithely assumed that existence is a property without ever considering the matter carefully. But this is not the case. The seventeenth-century empiricist Pierre Gassendi confronted Descartes with this criticism in the Fifth Set of Objections (and deserves credit for being the first to enunciate it): “existence is not a perfection either in God or in anything else; it is that without which no perfections can be present” (AT 7:323; CSM 2:224). As with most of his replies to Gassendi (whom he regarded as a loathsome materialist and quibbler), Descartes responded somewhat curtly. But it is clear from the discussion in section 2 that he had the resources for addressing this objection in a systematic manner.