“You haven’t answered me.”

“It is part of an answer to say that a question is important. I am considered by your rulers a valuable piece of property. They should ask whether my value is as great as it seems. They should ask whether my answering questions will do good or harm.”

“Which is it?”

“Harm, great harm.”

Siebling was staggered. He said, “But if you answer truthfully—”

“The process of coming at the truth is as precious as the final truth itself. I cheat you of that. I give your people the truth, but not all of it, for they do not know how to attain it of themselves. It would be better if they learned that, at the expense of making many errors.”

“I don’t agree with that.”

“A scientist asks me what goes on within a cell, and I tell him. But if he had studied the cell himself, even though the study required many years, he would have ended not only with this knowledge, but with much other knowledge, of things he does not even suspect to be related. He would have acquired many new processes of investigation.”

“But surely, in some cases, the knowledge is useful in itself. For instance, I hear that they’re already using a process you suggested for producing uranium cheaply to use on Mars. What’s harmful about that?”

“Do you know how much of the necessary raw material is present? Your scientists have not investigated that, and they will use up all the raw material and discover only too late what they have done. You had the same experience on Earth? You learned how to purify water at little expense, and you squandered water so recklessly that you soon ran short of it.”