"Well, shaking hands, for example," Stanton said after a pause. "We still do that, even if we don't have it fixed solidly in our heads that we must do it. I suppose it would never occur to a Nipe not to perform such a ritual."

"Just so," Yoritomo agreed vigorously. "Such things, once established in the minds of the race, would tend to remain. But it is a characteristic of a ritual-taboo system that it resists change. Change is evil. Change is wrong. We must use what we know to be true, not try something that has never been tried before. In a ritual-taboo system, a thing which is not ritual is, ipso facto, taboo. How, then, can we account for their high technological achievements?"

"The pragmatic engineering approach, I imagine," Stanton said. "If a thing works, then go ahead and use it. It is usable. If not, it isn't."

"Approximately," said Yoritomo. "But only approximately. Now it is my turn to lecture." He put his pipe in an ashtray and held up a long, bony finger. "Firstly, we must remember that the Nipe is equipped with a functioning imagination. Secondly, he has in his memory a tremendous amount of data, all ready at hand. He is capable of working out theories in his head, you see. Like the ancient Greeks, he finds no need to test such theories—unless his thinking indicates that such an experiment would yield something useful. Unlike the Greeks, he has no aversion to experiment. But he sees no need for useless experiment, either.

"Oh, he would learn, yes. But once a given theory proved workable, how resistant he would be to a new theory. Innovators, even in our own culture, have a very hard time working against the great inertia of a recognized theory. How much harder it would be in a ritual-taboo society with a perfect memory! How long—how incredibly long—it would take such a race to achieve the technology the Nipe now has!"

"Hundreds of thousands of years," said Stanton.

Yoritomo shook his head briskly. "Puh! Longer! Much longer!" He smiled with satisfaction. "I estimate that the Nipe race first invented the steam engine not less than ten million years ago!"

He kept smiling into the dead silence that followed.

After a long minute, Stanton said: "What about atomic energy?"

"At least two million years ago," Yoritomo said. "I do not think they have had the interstellar drive more than some fifty thousand years."