Descartes denied that the senses reveal the natures of substances. He held that in fact the human intellect is able to perceive the nature of reality through a purely intellectual perception. This means that, in order to procure the fundamental truths of metaphysics, we must “withdraw the mind from the senses” (7:4, 12, 14) and turn toward our innate ideas of the essences of things, including the essences of mind, matter, and an infinite being (God). Descartes constructed the Meditations so as