"We have about twenty already written and ready to produce," the plump man said comfortably, "and ideas for twice as many that the planning staff is working on now." The elderly man accepted that and took another cautious sip of wine. "What I wonder, though, is whether you can really say that history can be changed." "Well, of course--" The television man was taken aback; one always seems to be when a basic assumption is questioned. "Of course, we only know what really did happen, but it stands to reason if something had happened differently, the results would have been different, doesn't it?" "But it seems to me that everything would work out the same in the long run. There'd be some differences at the time, but over the years wouldn't they all cancel out?" "_Non, non, Monsieur!_" the man with the book, who had been outside the conversation until now, told him earnestly. "Make no mistake; 'istoree can be shange'!" I looked at him curiously. The accent sounded French, but it wasn't quite right. He was some kind of a foreigner, though; I'd swear that he never bought the clothes he was wearing in this country. The way the suit fitted, and the cut of it, and the shirt-collar, and the necktie. The book he was reading was Langmuir's _Social History of the American People_--not one of my favorites, a bit too much on the doctrinaire side, but what a bookshop clerk would give a foreigner looking for something to explain America. "What do you think, Professor?" the plump man was asking me. "It would work out the other way. The differences wouldn't cancel out; they'd accumulate. Say something happened a century ago, to throw a presidential election the other way. You'd get different people at the head of the government, opposite lines of policy taken, and eventually we'd be getting into different wars with different enemies at different times, and different batches of young men killed before they could marry and have families--different people being born or not being born. That would mean different ideas, good or bad, being advanced; different books written; different inventions, and different social and economic problems as a consequence." "Look, he's only giving himself a century," the colonel added. "Think of the changes if this thing we were discussing, Columbus sailing under the English flag, had happened. Or suppose Leif Ericson had been able to plant a permanent colony in America in the Eleventh Century, or if the Saracens had won the Battle of Tours. Try to imagine the world today if any of those things had happened. One thing you can be sure of--any errors you make in trying to imagine such a world will be on the side of over-conservatism." The sandy-haired man beside me, who had been using his highball for a crystal ball, must have glimpsed in it what he was looking for. He finished the drink, set the empty glass on the stand-tray beside him, and reached back to push the button.