"The compulsion to do their jobs," McIntosh continued, "is unchanged because the primary function banks are sealed circuits and can't be tampered with. But in each generation, they have their secondary memory circuits wiped clean and have to start all over, getting whatever general knowledge they can from the last generation."
Drummond snapped his fingers excitedly. "That's why they don't know what we are! Their idea of Man had to be passed down by word of mouth. And it got all distorted in the process!"
Angus's stare, more solicitous now, swept slowly over the prostrate robots. "More important, that's why they developed a religion. What's the main difference between human and robotic intelligence? It's that our span of life is limited on one end by birth, the other by death—mysteries of origin and destiny that can't be explained. You see, the ordinary clunker understands where he came from and where he's going. But here are robots who have to struggle with those mysteries—birth and death of the conscious intellect which they themselves once knew, and forgot, and now have turned into myths."
"So they start thinking in terms of religion," Drummond said. "Well, that clears up the whole thing, doesn't it?"
"Not quite. It doesn't explain why the religion they've invented parallels ours so closely. And it doesn't tell us who Jackson is."
Drummond ran thick fingernails against the stubble on his cheeks. "Jackson is my Supervisor. I shall not rust. He maketh me to adjust my joint tension—" He stopped and frowned. "I've heard that before somewhere, only it sounded different."
Angus gave him a wry, tired smile. "Sure. It's practically the Psalm of David. Now you see why the resemblance is driving me batty."
The robots stirred. Several of them stood up and plodded into the cave. The others continued repeating their endless praise and devotion—prayers in every sense of the word except common sense.
Angus leaned back against the cliff and let the sun's heat warm him.