The document discusses different philosophical views on the relationship between the mind and body known as the mind-body problem. It describes Cartesian dualism, the view proposed by Descartes that the mind and body are two distinct substances that can causally interact. According to Cartesian dualism, the mind is a nonphysical, indivisible soul, while the body is a mechanistic system. Descartes believed the pineal gland was the point of interaction between these two distinct entities. However, the exact nature of their interaction remains mysterious.