He laughed until tears came into his eyes, slapping his knee delightedly. Jasso stood there, looking blank.
"No, the Calculator's not haywire, Jasso," said Tern, when he could get his breath. "It just has all the facts, and it correlates facts we don't even think about. The reason we get funny ideas about it sometimes is because the Calculator can't talk. As you explained, it can just answer questions, and sometimes we don't ask the right questions.
"From what's happened, I'd say the question you asked the Calculator when you were looking for second-generation probabilities was not 'the offspring of two people.' It was 'offspring resulting from the marriage of two people.' Isn't that right?"
"It seemed the proper way to put the question," answered Jasso a little stiffly.
Tern began laughing again. "It was the right question to put," he choked, "but illegitimacy was the key to the whole thing!
"Look: the Calculator had all the facts. It knew all about the emotional make-up of Lao, Grida and Alina. It knew that Alina was Grida's sister.
"The probability course is obvious! Given a marriage between Lao and Grida, the probability was high that he would meet her sister, Alina, under convenient circumstances. The probability was high, too, considering the emotional make-up of the three, that Lao and Alina would fall in love. Under our present social scheme, an illegitimate child was likely. So there you are."
"Chief, I know you've been in this business a lot longer than I have," said Jasso slowly. "I've got to confess now that I can't see the slightest reason why the probability for a child of Lao and Alina should be so much higher under these circumstances than if the two of them just met and got married."
"Environment, my boy! It's just as important as heredity. Lao's marriage to Grida was the key to the whole thing. Grida is a motherly, fiercely conscientious type of woman who would insist on rearing her husband's child—no matter who the mother was. And of course the courts would uphold her."