Seldon frowned. “I see what you mean, Sire, but that is equally impossible.”

“Impossible?”

“Well, at any rate, impractical. Don’t you see? If you can’t start with human emotions and reactions and predict the future they will bring about, you can’t do the reverse either. You can’t start with a future and predict the human emotions and reactions that will bring it about.”

Cleon looked frustrated. His lips tightened. “And your paper, then?… Is that what you call it, a paper?… Of what use is it?”

“It was merely a mathematical demonstration. It made a point of interest to mathematicians, but there was no thought in my mind of its being useful in any way.”

“I find that disgusting,” said Cleon angrily.

Seldon shrugged slightly. More than ever, he knew he should never have given the paper. What would become of him if the Emperor took it into his head that he had been made to play the fool?

And indeed, Cleon did not look as though he was very far from believing that. “Nevertheless,” he said, “what if you were to make predictions of the future, mathematically justified or not; predictions that government officials, human beings whose expertise it is to know what the public is likely to do, will judge to be the kind that will bring about useful reactions?”

“Why would you need me to do that? The government officials could make those predictions themselves and spare the middleman.”

“The government officials could not do so as effectively. Government officials do make statements of the sort now and then. They are not necessarily believed.”

“Why would I be?”

“You are a mathematician. You would have calculated the future, not… not intuited it-if that is a word.”

“But I would not have done so.”

“Who would know that?” Cleon watched him out of narrowed eyes. There was a pause.

Seldon felt trapped. If given a direct order by the Emperor, would it be safe to refuse? If he refused, he might be imprisoned or executed. Not without trial, of course, but it is only with great difficulty that a trial can be made to go against the wishes of a heavy-handed officialdom, particularly one under the command of the Emperor of the vast Galactic Empire. He said finally, “It wouldn’t work.”

“Why not?”

“If I were asked to predict vague generalities that could not possibly come to pass until long after this generation and, perhaps, the next were dead, we might get away with it, but, on the other hand, the public would pay little attention. They would not care about a glowing eventuality a century or two in the future.

“To attain results,” Seldon went on, “I would have to predict matters of sharper consequence, more immediate eventualities. Only to these would the public respond. Sooner or later, though-and probably sooner-one of the eventualities would not come to pass and my usefulness would be ended at once. With that, your popularity might be gone, too, and, worst of all, there would be no further support for the development of psychohistory so that there would be no chance for any good to come of it if future improvements in mathematical insights help to make it move closer to the realm of practicality.”

Cleon threw himself into a chair and frowned at Seldon. “Is that all you mathematicians can do? Insist on impossibilities?”

Seldon said with desperate softness, “It is you, Sire, who insist on impossibilities.”

“Let me test you, man. Suppose I asked you to use your mathematics to tell me whether I would some day be assassinated? What would you say?”

“My mathematical system would not give an answer to so specific a question, even if psychohistory worked at its best. All the quantum mechanics in the world cannot make it possible to predict the behavior of one lone electron, only the average behavior of many.”

“You know your mathematics better than I do. Make an educated guess based on it. Will I someday be assassinated?”

Seldon said softly, “You lay a trap for me, Sire. Either tell me what answer you wish and I will give it to you or else give me free right to make what answer I wish without punishment.”

“Speak as you will.”

“Your word of honor?”

“Do you want it an writing?” Cleon was sarcastic.

“Your spoken word of honor will be sufficient,” said Seldon, his heart sinking, for he was not certain it would be.

“You have my word of honor.”

“Then I can tell you that in the past four centuries nearly half the Emperors have been assassinated, from which I conclude that the chances of your assassination are roughly one in two.”

“Any fool can give that answer,” said Cleon with contempt. “It takes no mathematician.”

“Yet I have told you several times that my mathematics is useless for practical problems.”

“Can’t you even suppose that I learn the lessons that have been given me by my unfortunate predecessors?”

Seldon took a deep breath and plunged in. “No, Sire. All history shows that we do not learn from the lessons of the past. For instance, you have allowed me here in a private audience. What if it were in my mind to assassinate you? Which it isn’t, Sire,” he added hastily.

Cleon smiled without humor. “My man, you don’t take into account our thoroughness-or advances in technology. We have studied your history, your complete record. When you arrived, you were scanned. Your expression and voiceprints were analyzed. We knew your emotional state in detail; we practically knew your thoughts. Had there been the slightest doubt of your harmlessness, you would not have been allowed near me. In fact, you would not now be alive.”

A wave of nausea swept through Seldon, but he continued. “Outsiders have always found it difficult to get at Emperors, even with technology less advanced. However, almost every assassination has been a palace coup. It is those nearest the Emperor who are the greatest danger to him. Against that danger, the careful screening of outsiders is irrelevant. And as for your own officials, your own Guardsmen, your own intimates, you cannot treat them as you treat me.”

Cleon said, “I know that, too, and at least as well as you do. The answer is that I treat those about me fairly and I give them no cause for resentment.”

“A foolish-” began Seldon, who then stopped in confusion.

“Go on,” said Cleon angrily. “I have given you permission to speak freely. How am I foolish?”

“The word slipped out, Sire. I meant ‘irrelevant.’ Your treatment of your intimates is irrelevant. You must be suspicious; it would be inhuman not to be. A careless word, such as the one I used, a careless gesture, a doubtful expression and you must withdraw a bit with narrowed eyes. And any touch of suspicion sets in motion a vicious cycle. The intimate will sense and resent the suspicion and will develop a changed behavior, try as he might to avoid it. You sense that and grow more suspicious and, in the end, either he is executed or you are assassinated. It is a process that has proved unavoidable for the Emperors of the past four centuries and it is but one sign of the increasing difficulty of conducting the affairs of the Empire.”

“Then nothing I can do will avoid assassination.”

“No, Sire,” said Seldon, “but, on the other hand, you may prove fortunate.”

Cleon’s fingers were drumming on the arm of his chair. He said harshly, “You are useless, man, and so is your psychohistory. Leave me.” And with those words, the Emperor looked away, suddenly seeming much older than his thirty-two years.

“I have said my mathematics would be useless to you, Sire. My profound apologies.” Seldon tried to bow but at some signal he did not see, two guards entered and took him away.

Cleon’s voice came after him from the royal chamber. “Return that man to the place from which he was brought earlier.”