Why, Robot? Understanding AI ethics

Not many people know that Isaac Asimov didn't originally write his three laws of robotics for I, Robot. They actually first appeared in "Runaround", the 1942 short story*. Robots mustn't do harm, he said, or allow others to come to harm through inaction. They must obey orders given by humans unless they violate the first law. And the robot must protect itself, so long as it doesn't contravene laws one and two.