“It puts an end to war—not only to the last cycle of wars, but to the next and to all of them. Unless—”

A long pause, and Dr. Calvin encouraged him by repetition. “Unless—”

The fire crouched and skittered along a log, then popped up.

“Unless,” said the Co-ordinator, “the Machines don’t fulfill their function.”

“I see. And that is where those trifling maladjustments come in which you mentioned awhile ago—steel, hydroponics and so on.”

“Exactly. Those errors should not be. Dr. Silver tells me they cannot be.”

“Does he deny the facts? How unusual!”

“No, he admits the facts, of course. I do him an injustice. What he denies is that any error in the machine is responsible for the so-called (his phrase) errors in the answers. He claims that the Machines are self-correcting and that it would violate the fundamental laws of nature for an error to exist in the circuits of relays. And so I said——”

“And you said, ‘Have your boys check them and make sure, anyway.’”

“Susan, you read my mind. It was what I said, and he said he couldn’t.”

“Too busy?”

“No, he said that no human could. He was frank about it. He told me, and I hope I understand him properly, that the Machines are a gigantic extrapolation. Thus— A team of mathematicians work several years calculating a positronic brain equipped to do certain similar acts of calculation. Using this brain they make further calculations to create a still more complicated brain, which they use again to make one still more complicated and so on. According to Silver, what we call the Machines are the result of ten such steps.”

“Ye-es, that sounds familiar. Fortunately, I’m not a mathematician.—Poor Vincent. He is a young man. The Directors before him, Alfred Lanning and Peter Bogert, are dead, and they had no such problems. Nor had I. Perhaps roboticists as a whole should now die, since we can no longer understand our own creations.”

“Apparently not. The Machines are not superbrains in Sunday supplement sense,—although they are so pictured in the Sunday supplements. It is merely that in their own particular province of collecting and analyzing a nearly infinite number of data and relationships thereof, in nearly infinitesimal time, they have progressed beyond the possibility of detailed human control.

“And then I tried something else. I actually asked the Machine. In the strictest secrecy, we fed it the original data involved in the steel decision, its own answer, and the actual developments since,—the overproduction, that is,—and asked for an explanation of the discrepancy.”

“Good, and what was its answer?”

“I can quote you that word for word: ‘The matter admits of no explanation.’”

“And how did Vincent interpret that?”

“In two ways. Either we had not given the Machine enough data to allow a definite answer, which was unlikely. Dr. Silver admitted that. —Or else, it was impossible for the Machine to admit that it could give any answer to data which implied that it could harm a human being. This, naturally, is implied by the First Law. And then Dr. Silver recommended that I see you.”