"For the sake of argument, then...." Banning nodded.
"All right. Presupposing he does not want to see human beings—for whatever reason—there are several mechanisms he could use."
"He didn't even have to come back," Banning pointed out.
"That's one of the mechanisms. But he did come back. Why? Problem one, for the future. Mechanism two: Catalepsy. Suspension of all sensation and consciousness."
"Obviously not the case."
"Right. Mechanism three," Colin went on, ticking the points off on his fingers, "partial disorientation. Loss of perception of a single class of objects, human beings."
"Even that isn't entirely true," Banning said. "He felt people."
"That's right. And I think this is our opening wedge. Of the possible means of avoidance I named, partial disorientation is the least successful of all. It involves too many contradictions. He was disturbed by the microphones, for example. Why? Because they are meaningful only in a context of human beings. Communication. He would have to do some fancy twisting to avoid the notion of human beings. The same goes for any other human artifact. Somehow, in order to make the world 'reasonable' in his own terms, he has to explain the existence of these things, without admitting the existence of people who made and use them."
"Impossible."
"Very nearly. It means that some facet of his personality must be continually making decisions about what can be recognized and what cannot. His censoring mechanism is in a constant scramble to prevent certain data from reaching his conscious mind. It has to justify and explain away all data which would eventually point to the existence of human beings."