All our power lies in both mind and body; we employ the mind to rule, the body rather to serve; the one we have in common with the Gods, the other with the brutes.
Bio: George David Wald was an American scientist who was best known for his work with pigments in the retina. He won a share of the 1967 Nobel Prize in Physiology or Medicine with Haldan Keffer Hartline and Ragnar Granit.