The story of the brain's separation from the body begin with Rene Descartes. The most influential philosopher of the seventeenth century, Descartes divided being into two distinct substances: a holy soul and a mortal carcass. The soul was the source of reason, science, and everything nice. Our flesh, on the other hand, was "clock-like," just a machine that bleeds. With this schism, Descartes condemned the body to a life of subservience, a power plant for the brain's light bulbs.