  Descartes famously calls the senses into doubt in the First Meditation, and he affirms in Meditation Six that the senses are not meant to provide knowledge of the “essential nature” of external objects (7:83). In that way, his position in the Meditations differs from that in the Rules, for in that work he allowed that some “simple natures” pertaining to corporeal things can and should be considered through the images of the senses (10:383, 417). In the Meditations, he held that the essence of matter could be apprehended by innate ideas, independently of any sensory image (7:64–5, 72–3). To that extent, his later position agrees with the Platonic tradition in philosophy, which denigrated sensory knowledge and held that the things known by the intellect have a higher reality than the objects of the senses. Descartes, however, was no Platonist, a point to which we will return. His attitude toward the senses in his mature period was not one of total disparagement.