He stared at the skimming figures of the temporometer. Even the scaler gauge, which measured in units of Kilocenturies, and which the men had adjusted for this particular purpose, was clicking at minute intervals.
He said, "You should not have come."
Harlan shrugged. "Why not?"
"It disturbs me. No sensible reason. Call it a long-standing superstition of mine. It makes me restless." He clasped his hands together, holding them tightly.
Harlan said, "I don't understand you."
Twissell seemed eager to talk, as though to exorcise some mental demon. He said, "Maybe you'll appreciate this, at that. You're the expert on the Primitive. How long did man exist in the Primitive?"
Harlan said, "Ten thousand Centuries. Fifteen thousand, maybe."
"Yes. Beginning as a kind of primitive apelike creature and ending as Homo sapiens. Right?"
"It's common knowledge. Yes."
"Then it must be common knowledge that evolution proceeds at a fairly rapid pace. Fifteen thousand Centuries from ape to Homo sapiens."
"Well?"
"Well, I'm from a Century in the 30,000's--"
(Harlan could not help starting. He had never known Twissell's homewhen or known of anyone who did.)
"I'm from a Century in the 30,000's," Twissell said again, "and you're from the 95th. The time between our homewhens is twice the total length of time of man's existence in the Primitive, yet what change is there between us? I was born with four fewer teeth than you, and without an appendix. The physiological differences about end with that. Our metabolism is almost the same. The major difference is that your body can synthesize the steroid nucleus and my body can't, so that I require cholesterol in my diet and you don't. I was able to breed with a woman of the 575th. That's how undifferentiated with time the species is."
Harlan was unimpressed. He had never questioned the basic identity of man throughout the Centuries. It was one of those things you lived with and took for granted. He said, "There have been cases of species living unchanged through millions of Centuries."
"Not many, though. And it remains a fact that the cessation of human evolution seems to coincide with the development of Eternity. Just coincidence? It's not a question which is considered, except by a few here and there like Sennor, and I've never been a Serinor. I didn't believe speculation was proper. If something couldn't be checked by a Computaplex, it had no business taking up the time of a Computer. And yet, in my younger days, I sometimes thought--"
"Of what?" Harlan thought: Well, it's something to listen to, anyway.
"I sometimes thought about Eternity as it was when it was first established. It stretched over just a few Centuries in the 30's and 40's, and its function was mostly trade. It interested itself in the ref orestation of denuded areas, shipping topsoil back and forth, fresh water, fine chemicals. Those were simple days.
"But then we discovered Reality Changes. Senior Computer Henry Wadsman, in the dramatic manner with which we are all acquainted, prevented a war by removing the safety brake of a Congressman's ground vehicle. After that, more and more, Eternity shifted its center of gravity from trade to Reality Change. Why?"
Harlan said, "The obvious reason. Betterment of humanity."
"Yes. Yes. In normal times, I think so too. But I'm talking of my nightmare. What if there were another reason, an unexpressed one, an unconscious one. A man who can travel into the indefinite future may meet men as far advanced over himself as he himself is over an ape. Why not?"
"Maybe. But men are men--"
"-even in the 70,000th. Yes, I know. And have our Reality Changes had something to do with it? We bred out the unusual. Even Sennor's homewhen with its hairless creatures is under continual question and that's harmless enough. Perhaps in all honesty, in all sincerity, we've prevented human evolution because we don't want to meet the supermen."
Still no spark was struck. Harlan said, "Then it's done. \Vhat does it matter?"
"But what if the superman exists just the same, further upwhen than we can reach? We control only to the 70,000th. Beyond that are the Hidden Centuries! Why are they hidden? Because evolved man does not want to deal with us and bars us from his time? Why do we allow them to remain hidden? Because we don't want to deal with them and, having failed to enter in our first attempt, we refuse even to make additional attempts? I don't say it's our conscious reason, but conscious or unconscious, it's a reason."
"Grant everything," said Harlan sullenly. "They're out of our reach and