The general interrupted with a measure of authority. "I would like to explain that bit. I hadn’t been aware that Dr. Calvin was unacquainted with the situation. I needn’t tell you, Dr. Calvin, that there always has been strong opposition to robots on the Planet. The only defense the government has had against the Fundamentalist radicals in this matter was the fact that robots are always built with an unbreakable First Law—which makes it impossible for them to harm human beings under any circumstance.