They mustn't harm a human being, they must obey human orders, and they must protect their own existence but only so long as that doesn't violate rules one and two. With these Three Laws of Robotics, humanity embarked on a bold new era of evolution that would open up enormous possibilities - and unforeseen risks. For the scientists who invented the earliest robots weren't content that their creations should remain programmed helpers, companions, and semisentient worker-machines.