The two men walked across the field to a road that led cityward. It was a narrow rutted brown track in the earth, and Goram snorted again. They walked along it. On a hill to the right stood a farm, a solid, substantial, contented-looking cluster of low tile-roofed stone buildings amid the open fields, and ahead on the horizon was the straggling misty line of the city. Otherwise they were alone.

“Are all your colonies this wild?” asked Goram.

“Just about,” said Heym, “though the environments are often radically different—everything from a planet that’s barely habitable desert to one that’s all jungle and swamp. That way, we can isolate the effects of environment. We even have one world equipped with complex robot-run cities, to see how untutored humans will react. There are three control stations, Earth-like planets where ordinary human types were left, and from them we’re getting valuable information on the path which terrestrial history actually took, we can test basic anthropological hypotheses and so on. Then there are a number of planets where different human types are planted—different races, different intelligence levels, and so on, to isolate the effects of heredity and see if there is any correlation of civilization with, say, physiology. But only here on Seventeen, populated exclusively by geniuses, has progress been rapid. All the other colonies are still in the stone ages or even lower, though there have been some unique responses made to severe environmental stimuli.”

“And you mean you just dumped your subjects down on all these worlds?”

“Crudely put, yes. For instance, before colonizing Seventeen we—that is, the Foundation—spent several generations breeding a pure genius strain of man. On Imperial orders, the Galaxy’s best brains were bred, and genetic control and selection were applied, until a stock had been developed whose members had only genius in the intellectual part of their heredity. Barring mutation or accident, both negligible, the people here and their children can only be geniuses. Then the few thousand adult end-products, who had naturally not been told what was in store for them, were seized and put under the action of memory erasers which left them able to walk and eat and little else. Then a couple of hundred were planted in each climatic region of this planet, near strategically placed invisible spy devices, and the observers sat back on their asteroid to see what would happen. That was fifteen hundred-odd years ago, but even in the forty or so years I’ve been in charge the change here has been very noticeable. In fact, on choosing the proper psychomathematical quantities to represent the various types of progress and plotting them against time, almost perfect exponential curves were obtained.”

“Sure. All progress, scientific progress anyway, is exponential.”

“Oh, no—quite the contrary. There are only a few sudden, brilliant, and—brief—periods of expansion in human history; long dreary dark ages intervene, and even the times of expansion are irregular. Nor has there ever been any real social progress made today as in the stone ages, law is based on force, though most of our force is the subtler psychotechnic kind—and even it is not essentially different from the taboo or priestcraft holding earlier cultures in check. I tell you, only on Seventeen has scientific progress been continuous, and only on Seventeen has there been any real social progress at all.”