interrupted the Psychologist: "You can move about in all directions of Space, but you cannot move about in Time."
"That is the germ of my great discovery. But you are wrong to say that we cannot move about in Time. For instance, if I am recalling an incident very vividly I go back to the instant of its occurrence; I become absent-minded, as you say. I jump back for a moment. Of course we have no means of staying back for any length of time any more than a savage or an animal has of staying six feet above the ground. But a civilized man is better off than the savage in this respect. He can go up against gravitation in a balloon, and why should we not hope that ultimately he may be able to stop or accelerate his drift along the Time Dimension; or even to turn about and travel the other way?"
"Oh, this", began Filby, "is all—— "