"Because I presume that it has not moved in space, and if it traveled into the future it would still be here all this time, since it must have traveled through this time."
"But," said I, "if it traveled into the past it would have been visible when we came first into this room; and last Thursday when we were here; and the Thursday before that; and so forth!"
"Serious objections," remarked the Rector with an air of impartiality, turning toward the Time Traveler.
"Not a bit," said the Time Traveler, and, to the Psychologist: "You think. You can explain that. It's presentation below the threshold, you know, diluted presentation."
"Of course," said the Psychologist, and reassured us. "That's a simple point in psychology. I should have thought of it. It's plain enough, and helps the paradox delightfully. We cannot see it, nor can we appreciate this machine, any more than we can
