  Descartes assigned two roles to the senses in the acquisition of human knowledge. First, he acknowledged that the senses are usually adequate for detecting benefits and harms for the body. Indeed, he considered their natural function to be “to inform the mind of what is beneficial or harmful for the composite of which the mind is a part” (7:83), that is, for the composite of mind and body. In this connection, he was agreeing with the conception of the function of the senses that was widely shared in the traditional literature in natural philosophy, including the Aristotelian literature, as well as in the medical literature on the natural functions of the senses.