Franz Joseph Gall developed the idea of phrenology in the early 1800's. He thought that a person's skull mirrored the brain, since the skull grew around the brain. He believed the brain was divided into parts, such as the organ for the self-defense instinct, love, pride, religion, memory of things, sense of colors, ambition, and kindness. Although not valid, Gall's conclusions convinced the scientific world that the brain influenced behavior. Therefore, mental illness had a physical basis. This helped bring about more humane treatment of the mentally ill. People used phrenology everywhere, from selecting employees, detecting bumps of destructiveness on children's heads, and hiring servants, to admitting students to school.