After a short break for a late lunch of the same monotonous foods, Derec set about installing the cellular arm in place of the robot’s original limb.
It was not an easy task, requiring both structural and functional marriages between two wildly divergent technologies. Derec worried about the functional link first, and not only because he expected it to be the tougher challenge. If the robot could not control the new arm, there was no point in going to the trouble of attaching it.
But the cellular arm apparently used the standard command set and carrier voltages. Though there was no evidence of any contacts or wiring in the stump end, the arm responded no matter where Derec attached the control bus.
Experimenting, he found that the arm responded even if he attached the control bus to the skin of the forearm, the palm of the hand, even the tips of two fingers. It seemed as though the cellular microrobots were smart enough to accept the command input from any location and channel it to the appropriate sites.
Once attached, the arm responded not only to all the robot’s basic motor commands, but even to some novel commands. With coaching from Derec, the robot was able to “think” an additional joint onto his arm between the elbow and wrist. In another test, Derec asked the robot to try to modify the cellular thumb and forefinger into long, slender microclamps.To his delight and amazement, it could. With the right command codes, the material of the arm seemed to be infinitely malleable.
But no matter how Derec prepared the mounting ring the arm was connected to, the right shoulder joint remained weaker than the left was or the original had been. At one point, the cellular arm broke loose completely when the robot tried to lift an object weighing less than twenty kilos. Even after he reattached it, Derec had doubts it would withstand the stresses of, for instance, a brawl.
“Looks like you’re going to have one strong arm and one smart one,” he told the robot. “Try not to forget which is which.”
“It is not possible for me to forget, sir.”
“This isn’t an off-the-shelf replacement,” Derec said sternly. “Until you’ve burned what it can do and can’t do into your pathways, you be careful with it. And never let anyone but me see you doing tricks with it, understand?”
While Derec was talking, the robot went rigid and its eyes dimmed. Derec knew what that meant, and fell silent. A moment later her heard the soft padding of Wolruf’s footsteps in the corridor. It was becoming a familiar sound, for it was Wolruf’s third visit to the lab that day. Aranimas, apparently occupied with the duties of “ship’s boss,” had managed only two.
Like the previous visits, this one was casual. Wolruf had no messages for him and no burning curiosity about what he was doing with the robot. It was almost as though she was using checking on him as an excuse to avoid other work, or trying to cultivate his friendship. But Derec kept up his guard. Wolruf was Aranimas’s lieutenant, no matter how sympathetic she might seem. Even her concern for him while he was being tortured, he had decided, was nothing more than a good cop, bad cop stage show meant to speed his surrender.
As before, Wolruf stayed but a few minutes, then continued on to some other task. As soon as she was out of earshot, the robot reanimated.
“I understand, sir,” it said, as though there had been no interruption.
“The next time you have to go down like that, you might spend your time trying to analyze the arm’s command set. Can you do that?”
“I can try, sir. It should be possible to separate those command codes which are valid from those which are nulls. However, I will have to be fully functional to test the valid codes and determine their function.”
“Let’s wait on that until we know we’re going to have some privacy.” He paused a moment to decide what he needed doing next. There was still the matter of reprogramming the robot, but that was also a job which required some assurance of privacy. The best opportunity seemed to be during shipboard night, which was also the best time to explore the ship.
Too much to do, too little time, Derec thought. But if he was going to make better use of the night hours than he had last night, he needed to be better rested. “Alpha.”
“Yes, Derec.”
“What time is it?”
“I do not know what time it is, since my temporal register has not been reset since I was deactivated. However, it has been fourteen decads since reinitialization.”
Decads were units of Auroran decimal time, Derec recalled. “I’m going to take a nap. Wake me in a Standard hour.”
“Yes, sir.”
But it was Aranimas, not the robot, who woke him.
“Are you finished? Is my servant ready?” he demanded, looming over Derec like some long-limbed water bird.
“Not yet,” Derec said sleepily, sitting up. He noted with satisfaction that the robot was standing inert by the workbench. It, at least, had not been taken by surprise.
“Then why do you rest? To keep me waiting?”
“I rest so I don’t get so tired that I make a mistake that’ll damage the robot,” Derec said. “Maybe your kind doesn’t have that need, but humans do.”
Aranimas did not take offense at Derec’s tone. “I have observed that humans are even less efficient than Narwe. You would make very poor workers, wasting one third of your time in rest.” He turned his back on Derec and went to where the robot stood. “But then perhaps that is why you have invented such machines, which labor in your service tirelessly. How is it done?”
“What do you mean?” Derec asked, coming to his feet.
“What is the source of energy?” Aranimasasked, tracing a line down the robot’s torso with his long fingers.
Derec knew that being evasive or pretending ignorance would only anger the alien. “A microfusion powerpack,” he said. “There’s one on the bench there, just to the left of the scanner.”
Aranimas picked up the damaged powerpack and studied it. “So small. How days’ service does it contain?”
“It depends on how hard the robot is working. The fuel capsule is good for several hundred days of light duty, like domestic service. A laborer would obviously need refueling more often.”
“Remarkable,” Aranimas said, returning the powerpack to the bench. One of his eyes seemed to focus briefly on the transplanted arm, then swung back toward Derec. “You are making progress?”
“I am.”
“How long until you are ready to activate it?”
“I’ll be ready to start testing its systems tomorrow or the next day. How soon it’ll be ready will depend on how much is wrong.”
Aranimas seemed to accept that. “The first job of this robot will be to help you make more robots.”
Frowning, Derec stepped forward. “How many more?”
“We will begin with fifty.”
Derec wondered if that figure represented the number of Narwe on board. He briefly enjoyed the thought of Aranimas replacing his browbeaten crew with an array of obedient robots, only to discover that, at a word from Derec, he couldn’t command them at all. But he could not kid himself or allow Aranimas to entertain unreasonable expectations.
“I don’t think you understand the complexity of these machines,” Derec said. “They’re not something you put together as a hobby, no matter how good a materials lab you have. And frankly, this isn’t a very good one. I’ll probably be able to get this robot put together and keep it repaired. But if you want fifty robots, you’re going to have to look somewhere else for them. I’m not magician enough to pull positronic brains or microfusion cells out of a hat.”
“If you had not destroyed your robot colony-,” Aranimas said, his voice rising.
“I told you before, the robots did that on their own,” Derec insisted. “But that doesn’t mean you’re stuck. You take this ship to any Spacer world and you’ll find millions of robots. And you won’t have to steal them, either. Robots are a major trade item between the worlds. Any one of them would be happy for a new customer.”
That was not entirely true, of course. It was highly doubtful the Spacers would willingly turn over examples of their most advanced technology to an alien race, and even if they were willing, there was the problem of what Aranimas could offer as payment. But if Derec could make Aranimas believe it was the truth, coax him to take the ship to a human world, he would at least have succeeded in alerting them to the aliens’ existence, and possibly have laid the groundwork for his own release.
“If commerce is so welcome, why did your robots destroy themselves?”
“Because you came in firing your weapons and declared yourself an enemy,” Derec said. “If you’d come in as a friend, it would have been different. Take me to your navigator. I’ll help him set a course for the nearest Spacer world.” And find out where we are in the process, he added silently.
“I will evaluate the options,” Aranimas said, moving toward the corridor. “In the meantime, you will continue your work. I will return tomorrow to see my robot activated.”
The reprogramming could not be postponed any longer, Derec decided, He did not think Aranimas would return soon. He would have to hope that Wolruf would not, either.
Unfortunately, Derec did not have the equipment to alter the robot’s programming directly, which would have been risky anyway. Since it was intimately bound up in the Laws of Robotics, the robot’s definition of what a human was comprised some of the most crucial and most deeply engraved patterns within its brain. What needed doing would have to be done more indirectly.
“Alpha,” he said. “Did you scan the organism that was just here?”
“Yes, Derec.”
“And earlier today, did you scan another type of organism visiting the lab?”
“Yes, Derec.”
“What’d you think of them?”
“I have no previous knowledge of humans of this type-”
That was the kind of response Derec had been fearing. “Stop. They’re not humans.”
“Sir, I am aware that my data library is not complete. However, I am unable to categorize them in any other fashion unless you can provide me with evidence for your assertion.”
“Compare their appearance with mine.”
“Sir, I acknowledge that there are numerous anomalous differences. However, those differences fall in areas where the definition of a human has a wide latitude, such as skin color and covering, dimensions, and vocal timbre. The similarities are in more fundamental areas such as bilateral symmetry, bipedal locomotion, oxygen respiration-”
“They are humanoid, as you are. But they are not human.”
“I note your assertion, sir, but I am unable to confirm it.”
Derec understood that he was not being called a liar. When it had no independent knowledge, a robot would ordinarily accept the word of a human as gospel. But a robot was under no obligation to accept a human’s claim that it was raining when its own sensors told it otherwise.
This was not that clear-cut an issue, but the robot was biased toward a generous definition of what a human was. Otherwise there was the danger of a robot’s being used as an assassin by the simple step of persuading it that its target was not a human. Derec understood, but even so was annoyed. “I suppose that if they had twelve arms and belched fire when they talked, you might believe me.”
“Sir, in the matter at hand the morphological considerations are not primary in my analysis.”
“Explain. What are the discriminators?”
“Sir, I base my conclusion on the observation that the organisms called Aranimas and Wolruf are intelligent beings capable of independent reasoned thought.”
“How do you know?”
“Sir, you carried on a dialogue with each of them. Although humans on occasion talk to nonanimate objects and may give the appearance of carrying on a dialogue with certain animals, I perceived your discussions as having a qualitatively different character.”
“Are you saying that because I treated them as human, you have to think of them that way?”
“Where there is uncertainty, as thee may be when a human wears a costume or disguise, I am obliged to use such cues as are available. Your behavior created a strong presumption that Aranimas and Wolruf are human.”
“I talk to you the same way I talked to them. Does that make you a human?”
“No, Derec. I am a robot, a technological artifact. To the degree that I may seem to be human, it is only because I have been designed to do so in order to more easily interact with humans.”
Derec was growing frustrated. “Tell me this, then. How do you tell the difference between a robot and a human at a distance?”
“Sir, just as I have an operational definition of that class of organisms called humans, I also have one of that class of objects called robots. It is ordinarily possible to distinguish between the two based on the characteristics they do not have in common. It is not a perfect system, however, and may be fooled, as by a humaniform robot of the type developed by Dr. Han Fastolfe.”
Derec had to concede the point to the robot.If only I could show it skin scrapings from the three of us-but if Aranimas or Wolruf happened to have a cellular structure, I’d be no better off. It might even decide its right arm is human-
“Robot, are Spacers, Settlers, and Earthpeople all human?” he asked suddenly.
“Yes.”
“Have you personally observed every member of those groups?”
“No, Derec. There are approximately eight billion Earthpeople, five billion Spacers, and-”
“If you have not observed them individually, how is it you are able to classify them all as human?”
“Spacers and Settlers are descendants of the original human community on Earth,” the robot replied. “Therefore, any individual correctly identified as a Settler or Spacer cannot be other than human.”
“Why is that?” Derec asked, though he knew the answer.
“They share a phylogenetic relationship. The offspring of a human must be human.”
“In other words, what really counts is biology-the genes and DNA humans carry in their cells.”
“Yes.”
“And the guidelines that are built into your definition of a human are simply shortcuts to make it unnecessary for you to subject everyone you encounter to a biological assay. The final criterion is DNA.”
“That is correct, Derec.”
“But you have no way of examining a person’s DNA directly.”
“No, sir.”
“Fine. You said that each of the anomalies in Aranimas’s appearance fell within the acceptable parameters for natural variation and mutation.”
“Yes, sir.”
“I ask you to calculate the probability that all of Aranimas’s anomalies would appear in a single organism.”
The robot scarcely hesitated. “The probability is extremely small.”
“And for Wolruf?”
“The probability is somewhat higher, but still on the order of one chance in ten to the fifteenth power.”
“In other words, there is less than a one in ten thousand chance that a mutation this extreme would have arisen once in all of human history. And here there are two of them, not only alive at the same time but in the same place, and both as different from each other as they are from me.”
“It is quite remarkable. No doubt further study of these individuals would be of great benefit.”
Derec sighed exasperatedly. “Listen, my thick-headed robot friend. Stop thinking one step at a time. Isn’t the probability that an independently evolved lifeform might be bipedal, bilateral, and oxygen-breathing greater than the probability that these creatures are mutant humans? Can’t Aranimas and Wolruf be intelligent without being human?”
“Yes, that is possible.” The robot paused, a sign of great activity in its positronic pathways. “However, since no independently evolved intelligent lifeforms are known, it is difficult to assign a probability to a specific form.”
“I challenge your premise,” Derec pounced. “Why are most robots humanoid?”
“Higher robots are humanoid because it is a successful generalized design and because-”
“The other reasons don’t matter,” Derec said. “Apply that standard to the question of Aranimas and Wolruf.”
Again the robot paused before answering. “My positromotive potentials are extremely high on both sides of the question,” it said at last. “I believe this state may be similar to that which a human describes as confusion.”
“Get to the point. What’s the verdict?”
“It is my tentative conclusion that Aranimas and Wolruf are not human.”
“You are not obliged by the First Law to protect them or the Second Law to obey them?”
“No, Derec.”
“Good,” he said with relief. “You can live. Now listen closely. I have some important instructions for you concerning our alien hosts-”