above all, from the First Foundation?" The Student probed for a hidden meaning to the question and failed to find it. He was troubled in his answer, "For the same reason that the details of the Plan as a whole must be hidden from Mankind in general. The laws of Psychohistory are statistical in nature and are rendered invalid if the actions of individual men are not random in nature. If a sizable group of human beings learned of key details of the Plan, their actions would be governed by that knowledge and would no longer be random in the meaning of the axioms of Psychohistory. In other words, they would no longer be perfectly predictable. Your pardon, Speaker, but I feel that the answer is not satisfactory." "It is well that you do. Your answer is quite incomplete. It is the Second Foundation itself which must be hidden, not simply the Plan. The Second Empire is not yet formed. We have still a society which would resent a ruling class of psychologists, and which would fear its development and fight against it. Do you understand that?" "Yes, Speaker, I do. The point has never been stressed? "Don"t minimize. It has never been made ?in the classroom, though you should be capable of deducing it yourself. This and many other points we will make now and in the near future during your apprenticeship. You will see me again in a week. By that time, I would like to have comments from you as to a certain problem which I now set before you. I don"t want complete and rigorous mathematical treatment. That would take a year for an expert, and not a week for you. But I do want an indication as to trends and directions "You have here a fork in the Plan at a period in time of about half a century ago. The necessary details are included. You will note that the path followed by the assumed reality diverges from all the plotted predictions; its probability being under one percent. You will estimate for how long the divergence may continue before it becomes uncorrectable. Estimate also the probable end if uncorrected, and a reasonable method of correction." The Student flipped the Viewer at random and looked stonily at the passages presented on the tiny, built-in screen. He said: "Why this particular problem, Speaker? It obviously has significance other than purely academic." "Thank you, my boy. You are as quick as I had expected. The problem is not suppositiiious. Nearly half a century ago, the Mule burst into Galactic history and for ten years was the largest single fact in the universe. He was unprovided for; uncalculated for. He bent the Plan seriously, but not fatally. "To stop him before he did become fatal, however, we were forced to take active part against him. We revealed our existence, and infinitely worse, a portion of our power. The First Foundation has learned of us, and their actions are now predicated on that knowledge. Observe in the problem presented. Here. And here. "Naturally, you will not speak of this to anyone." There was an appalled pause, as realization seeped into the Student. He said: "Then the Seldon Plan has failed!" "Not yet. It merely may have failed. The probabilities of success are still twenty-one point four percent, as of the last assessment." 9 The Conspirators For Dr. Darell and Pelleas Anthor, the evenings passed in friendly intercourse; the days in pleasant unimportance. It might have been an ordinary visit. Dr. Darell introduced the young man as a cousin from across space, and interest was dulled by the clich?