Pythagoras (ca. 580–500 B.C.) is the Greek scholar who suggested that the brain is at the center of human reasoning and plays a central role in the "soul's life."
Pythagoras believed that an abstract world consisting of numbers and numerical relationships exerted an influence on the physical world. He created a dualistic view of humans by saying that in addition to our body, we have a mind (soul), which through reasoning could understand the abstract world of numbers. Furthermore, he believed the human soul to be immortal. Pythagoras' philosophy had a major influence on Plato and, through Christianity, on the entire Western world.