Evidence (short story)

Background

Isaac Asimov wrote "Evidence" during his time in the U.S. Army, from November 1945 to July 1946, making it his sole story from that period. He started it in January at Camp Lee and finished it that April in Honolulu, while awaiting deployment to Operation Crossroads.

The story was sold to editor John W. Campbell the same month. Orson Welles bought the film rights for $250, leading Asimov to believe a movie would make him famous, but Welles never used the script. Asimov's wife, Gertrude Blugerman, urged him to ask for more money, yet neither understood that option payments could be renewed every few years, letting the rights lapse if Welles failed to act.

Plot summary

Stephen Byerley suffered severe injuries in a car crash. After a long recovery, he rose to prominence as a district attorney and later launched a campaign for mayor in a major American city. His opponent, Francis Quinn, and his political machine spread the story that the real Byerley was left permanently disfigured and crippled by the accident. According to Quinn, the person appearing in public is a humanoid robot built by the real Byerley, who now serves as the robot's hidden "teacher" while away on unspecified scientific work.

Most voters dismiss this claim, but if true, it would end Byerley's campaign because only humans can legally hold office. Quinn goes to U.S. Robots and Mechanical Men, the sole maker of positronic robot brains, seeking evidence that Byerley must be a robot. He points out that no one has ever seen Byerley eat or sleep. Every attempt to confirm or refute Byerley's humanity fails, yet Quinn's smear campaign gradually sways voters until it becomes the sole focus of the election.

Alfred Lanning and Dr. Susan Calvin, U.S. Robots' Chief Robopsychologist, meet with Byerley. Calvin offers him an apple, and Byerley takes a bite, though he might have been built with a stomach. Quinn tries to secretly X-ray him, but Byerley wears a device that clouds the camera, explaining that he is protecting his civil rights, just as he would for others if elected. His opponents argue that a robot has no civil rights, but Byerley counters that they must first prove he is a robot before denying his human rights, including his right to refuse a physical exam.

Calvin notes that if Byerley is a robot, he must follow the Three Laws of Robotics. Breaking one of those Laws would prove he is human, since no robot can defy its core programming. Byerley never seeks the death penalty and claims he has never prosecuted an innocent person, but following the Laws does not confirm he is a robot, because the Laws are rooted in human morality. As Calvin puts it, "He may simply be a very good man." To prove he is human, Byerley would need to show he can harm a person, which would break the First Law.