Jean Pierre Flourens
Marie Jean Pierre Flourens (13 April 1794 – 6 December 1867), father of Gustave Flourens, was a French physiologist, the founder of experimental brain science and a pioneer in anesthesia. Through the study of ablations on animals, he was the first to prove that the mind was located in the brain, not the heart.
Galen
The Stoics, according to Galen, failed to give a credible answer for the localization of functions of the psyche, or the mind. Through his use of medicine, he was convinced that he came up with a better answer, the brain. The Stoics only recognized the soul as having one part, which was the rational soul and they claimed it would be found in the heart. Galen, following Plato's idea, came up with two more parts to the soul.