After a long minute, Scanton said: "What about atomic energy?"
"At least two million years ago. I do not think they have had the interstellar drive more than fifty thousand years."
"No wonder our pet Nipe is so patient," Stanton said wonderingly. "I wonder what their individual life span is."
"Not long, in comparison," said Yoritomo. "Perhaps no longer than our own, perhaps five hundred years. Considering their handicaps, they have done quite well. Quite well, indeed, for a race of illiterate cannibals."
"How's that again?" Stanton realized that the scientist was quite serious.
"Hadn't it occurred to you, my friend, that they must be cannibals? And that they are very nearly illiterate?"
"No," Stanton admitted, "it hadn't."
"The Nipe, like Man, is omnivorous. Specialization tends to lead any race up a blind alley, and dietary restrictions are a particularly pernicious form of specialization. A lion would starve to death in a wheat field. A horse would perish in a butcher shop full of steaks. A man will survive as long as there's something around to eat—even if it's another man.
"Also, Man, early in his career as top dog on Earth, began using a method of increasing the viability of the race by removing the unfit. It survives today in some societies. Before and immediately after the Holocaust, there were still primitive societies on Earth which made a rather hard ordeal out of the Rite of Passage—the ceremony that enabled a boy to become a Man, if he passed the tests.