>Powell's radio voice was tense in Donovan's car: "Now, look, let's start with the three fundamental Rules of Robotics - the three rules that are built most deeply into a robot's positronic brain." In the darkness, his gloved fingers ticked off each point.

>"We have: One, a robot may not injure a human being, or, through inaction, allow a human being to come to harm." "Right!"

>"Two," continued Powell, "a robot must obey the orders given it by human beings except where such orders would conflict with the First Law." "Right!"

>"And three, a robot must protect its own existence as long as such protection does not conflict with the First or Second Laws."