There was a long pause. Then R. Idda said, with unmoved voice, "My evidence was a lie. It was Dr. Humboldt whose work it was, and my master has attempted, wrongfully, to appropriate the credit."
Baley said, "Very well, boy. You are instructed to say nothing to anyone about this until given permission by the captain of the ship. You are excused."
The screen blanked out and Baley puffed at his pipe. "Do you suppose the captain heard that, Daneel?"
"I am sure of it. He is the only witness, except for us."
"Good. Now for the other."
"But is there any point to that, friend Elijah, in view of what R. Idda has confessed?"
"Of course there is. R. Idda's confession means nothing."
"Nothing?"
"Nothing at all. I pointed out that Dr. Humboldt's position was the worse. Naturally, if he were lying to protect Sabbat, he would switch to the truth as, in fact, he claimed to have done. On the other hand, if he were telling the truth, he would switch to a lie to protect Humboldt. It's still mirror-image and we haven't gained anything."
"But then what will we gain by questioning R. Preston?"
"Nothing, if the minor-image were perfect-but it is not. After all, one of the robots is telling the truth to begin with, and one is lying to begin with, and that is a point of asymmetry. Let me see R. Preston. And if the transcription of R. Idda's examination is done, let me have it.
The projector came into use again. R. Preston stared out of it; identical with R. Idda in every respect, except for some trivial chest design.
Baley said, "Greetings, R. Preston." He kept the record of R. Idda's examination before him as he spoke.
"Greetings, sir," said R. Preston. His voice was identical with that of R. Idda.
"You are the personal servant of Alfred Ban Humboldt are you not?"
"I am, sir."
"For how long, boy?"
"For twenty-two years, sir."
"And your master's reputation is valuable to you?"
"Yes, sir."
"Would you consider it of importance to protect that reputation?"
"Yes, sir."
"As important to protect his reputation as his physical life?"
"No, sir."
"As important to protect his reputation as the reputation of another?"
R. Preston hesitated. He said, "Such cases must be decided on their individual merit, sir. There is no way of establishing a general rule."
Baley said, "If you decided that the reputation of your master were more important than that of another, say, that of Gennao Sabbat, would you lie to protect your master's reputation?"
"I would, sir."
"Did you lie in your testimony concerning your master in his controversy with Dr. Sabbat?"
"No, sir."
"But if you were lying, you would deny you were lying, in order to protect that lie, wouldn't you?"
"Yes, sir."
"Well, then," said Baley, "let's consider this. Your master, Alfred Barr Humboldt, is an old man of great reputation in mathematics, but he is an old man. If, in this controversy with Dr. Sabbat, he had succumbed to temptation and had acted unethically, he would suffer a certain eclipse of reputation, but his great age and his centuries of accomplishments would stand against that and would win out. Men would look upon this plagiaristic attempt as the mistake of a perhaps-sick old man, no longer certain in judgment.
"If, on the other hand, it were Dr. Sabbat who had succumbed to temptation, the matter would be much more serious. He is a young man, with a far less secure reputation. He would ordinarily have centuries ahead of him in which he might accumulate knowledge and achieve great things. This will be closed to him, now, obscured by one mistake of his youth. He has a much longer future to lose than your master has. You see, don't you, that Sabbat faces the worse situation and deserves the greater consideration?"
There was a long pause. Then R. Preston said, with unmoved voice, "My evidence was as I-"
At that point, he broke off and said nothing more. Baley said, "Please continue, R. Preston."
There was no response.
R. Daneel said, "I am afraid, friend Elijah, that R. Preston is in stasis. He is out of commission."
"Well, then," said Baley, "we have finally produced an asymmetry. From this, we can see who the guilty person is."
"In what way, friend Elijah?"
"Think it out. Suppose you were a person who had committed no crime and that your personal robot were a witness to that. There would be nothing you need do. Your robot would tell the truth and bear you out. If, however, you were a person who had committed the crime, you would have to depend on your robot to lie. That would be a somewhat riskier position, for although the robot would lie, if necessary, the greater inclination would be to tell the truth, so that the lie would be less firm than the truth would be. To prevent that, the crime-committing person would very likely have to order the robot to lie. In this way, First Law would be strengthened by Second Law; perhaps very substantially strengthened."
"That would seem reasonable," said R. Daneel.
"Suppose we have one robot of each type. One robot would switch from truth, unreinforced, to the lie, and could do so after some hesitation, without serious trouble. The other robot would switch from the lie, strongly reinforced, to the truth, but could do so only at the risk of burning out various positronic-track-ways in his brain and falling into stasis."
"And since R. Preston went into stasis-"
"R. Preston's master, Dr. Humboldt, is the man guilty of plagiarism. If you transmit this to the captain and urge him to face Dr. Humboldt with the matter at once, he may force a confession. If so, I hope you will tell me immediately."