In Little Lost Robot," by Isaac Asimov, why have some robots been impressioned with only part of the First Law of Robotics?"

"Little Lost Robot" is one of Isaac Asimov's many short stories dealing with the creation of artificial intelligence. The scientists in these stories realize that independent robots can pose a danger to humans, so by law they build into the robots' programming three rules, known as the Three Laws of Robotics:
  1. Robots must never harm human beings or, through inaction, allow a human being to come to harm.
  2. Robots must follow instructions from humans, unless said instructions violate rule 1.
  3. Robots must protect themselves from harm without violating Rules 1 and 2.

These rules seem perfectly logical, but they can present certain problems. In "Little Lost Robot," humans working on a "Hyperatomic Drive" must work for short periods around radiation. It is dangerous work, but precautions are taken, and no fatal accidents have occurred. Unfortunately, the robots are unable to define shades of harm, so whenever a human enters an area of radiation, even though safety measures are in place and the human would leave the area before any lasting damage could occur, any robots in the area, following the First Law, would drag the human into a safe area.

Naturally, this kept the humans from completing their tasks until all robots were cleared from the area. To make matters worse, if the radiation was strong enough, it would fry the robots' circuits, and the company would be out an expensive electronic worker.

To get around this problem, 12 Nestor robots were secretly impressioned with only the first part of the First Law: Robots must never harm human beings. The problem in "Little Lost Robot" begins when a frustrated physicist tells one robot, designated Nestor-10, to more or less get lost. The physicist, Gerald Black, was of course speaking colloquially, but Nestor-10 takes the order literally and, following the Second Law of Robotics, tries to lose himself.

Thus begins the search for the one altered Nestor robot among 63 identical Nestor robots before he can find his way to Earth, where he will not only be a danger to humans, but will also cause a great controversy.

Through the logical paradoxes and conundrums that his robots and scientists face, Asimov illustrates the complexity of human ethical choices in an ever-changing world, thereby giving us another glimpse, as all great literature does, of what it really means to be human.