may 15, 1500 - Rene Descartes Said that mind and matter and two separate domains that interact with one another (dualism) and therefore touch somewhere in the body (pineal gland) → believed the body functioned like a hydraulic machine, in the sense that he believed that when nerves experience physical sensations, they cause ripples in body fluid that travel up to the pineal gland, which then causes a psychological sensation; said that only the mind (not the fluid) can be a soul (Timeline)