The idea of Mind-Body Dualism stems from the French philosopher, Rene Descartes, who wrote a famous line that says "I think, therefore I am". During his time, many people thought human behavior was done by free will, or "reason". Descartes then formulated a dualistic model of nature. The model is split in two, one explains that our body functions like a machine which then results in reflexes due to external stimulation. For an example, if you accidentally touch fire with your fingers, and as a result, you are triggered by pain. The other perspective is that our mind chooses our behaviors, which are voluntary. For example, choosing what you want to eat. Descartes soon proposed that some human behaviors are reflexes due to external stimuli, while others are voluntary and are controlled by what we choose.