“I used to believe that myself,” Rostock said. “Lately I have not been sure. A world federalism could be devised which would let both civilizations keep their identities. Many such proposals have in fact been made, as you know. None has gotten beyond the talking stage. None ever will. Because you see, what maintains the war is not the difference between our two cultures, but their similarity.”

“Whoa, there!” Diaz bristled. “I resent that.”

“Please,” Rostock said. “I pass no moral judgments. For the sake of argument, at least, I can concede you the moral superiority, remarking only in parenthesis that Earth holds billions of people who not only fail to comprehend what you mean by freedom but would not like it if you gave it to them. The similarity I am talking about is technological. Both civilizations are based on the machine, with all the high organization and dynamism which this implies.”

“So?”

“So war is a necessity—Wait! I am not talking about ‘merchants of death,’ or ‘dictators needing an outside enemy,’ or whatever the current propaganda lines are. I mean that conflict is built into the culture. There must be an outlet for the destructive emotions generated in the mass of the people by the type of life they lead. A type of life for which evolution never designed them.

“Have you ever heard about L. F. Richardson? No? He was an Englishman in the last century, a Quaker, who hated war but, being a scientist, realized the phenomenon must be understood clinically before it can be eliminated. He performed some brilliant theoretical and statistical analyses which showed, for example, that the rate of deadly quarrels was nearly constant over the decades. There could be many small clashes or a few major ones, but the result was the same. Why were the United States and the Chinese Empire so peaceful during the nineteenth century? The answer is that they were not; they had their Civil War and Taiping Rebellion, which devastated them as much as required. I need not multiply examples. We can discuss this later in detail. I have carried Richardson’s work a good deal further and more rigorously. I say to you now only that civilized societies must have a certain rate of immolations.”

Diaz listened to silence for a minute before he said: “Well, I’ve sometimes thought the same. I suppose you mean we spacemen are the goats these days?”

“Exactly. War fought out here does not menace the planet. By our deaths we keep Earth alive.”

Rostock sighed. His mouth drooped. “Magic works, you know,” he said, “on the emotions of the people who practice it. If a primitive witch doctor told a storm to go away, the storm did not hear, but the tribe did and took heart. The ancient analogy to us, though, is the sacrificial king in the early agricultural societies; a god in mortal form, who was regularly slain so that the fields might bear fruit. This was not mere superstition. You must realize that. It worked—on the people. The rite was essential to the operation of their culture, to their sanity and hence to their survival.