(8) Sigmund Freud
Freud requires very little introduction, as his creation of the psychoanalytic wing of psychology has made him a household name. Freud divided our psyches into egos, superegos, and ids; advocated cocaine use for, among other things, indigestion; studied cerebral palsy; and made us all feel just a little bit weird about our relationships with our mothers. Finally, his notion of the Freudian slip gave us all a get-out-of-jail-free card for our occasional verbal lapses. Thanks, Sigmund.
(9) Samuel Colt
When Colt was a young sailor, he made his first handgun, which had the novel feature of a rotating cartridge cylinder that turned when the hammer was cocked. His first effort to mass-produce the revolver failed, but he did manage to invent a naval mine that was the first-ever remote control explosive. In 1847, though, the government caught onto the brilliance of Colt's quick-to-operate multiple shot and asked him to fill a large order. From that moment on, Colt revolvers became some of the most iconic and important firearms in American history.
Freud's contributions to psychology certainly changed the way we think about how we think. Colt's contributions to firearms technology changed the way we think about how we fight. Both are incredibly pivotal figures in history, but which one was the bigger genius?
[See the whole bracket here.]