With controls and speculum he hunted back through time, seeking the Builders. It was slow work, as he had found before. A passing shadow, a tedious retracing—and failure.
Once he was sure that he had seen such a shadow in the speculum. He set the controls back far enough to be sure that he had repassed it, armed himself with food and drink and waited.
He waited three weeks.
The shadow might have passed during the hours he was forced to take
out for sleep. But he felt sure that he was in the right period; he kept up the vigil.
He saw it.
It was moving toward the Gate.
When he pulled himself together he was halfway down the passageway leading away from the hall. He realized that he had been screaming. He still had an attack of the shakes.
Somewhat later he forced himself to return to the hall, and, with eyes averted, enter the control booth and return the spheres to zero. He backed out hastily and left the hall for his apartment. He did not touch the controls or enter the hail for more than two years.
It had not been fear of physical menace that had shaken his reason, nor the appearance of the creature—he could recall nothing of how it looked. It had been a feeling of sadness infinitely compounded which had flooded through him at the instant, a sense of tragedy, of grief insupportable and unescapable, of infinite weariness. He had been flicked with emotions many times too strong for his spiritual fiber and which he was no more fitted to experience than an oyster is to play a violin.
He felt that he had learned all about the High Ones a man could learn and still endure. He was no longer curious. The shadow of that vicarious emotion ruined his sleep, brought him sweating out of dreams.
One other problem bothered him—the problem of himself and his meanders through time. It still worried him that he had met himself coming back, so to speak, had talked with himself, fought with himself.
Which one was himself?
He was all of them, he knew, for he remembered being each one. How about the times when there had been more than one present?
By sheer necessity he was forced to expand the principle of nonidentity
—“Nothing is identical with anything else, not even with itself”—to include the ego. In a four-dimensional continuum each event is an absolute individual, it has its space coordinates and its date. The Bob Wilson he was right now was not the Bob Wilson he had been ten minutes ago. Each was a discrete section of a four-dimensional process. One resembled the other in many particulars, as one slice of bread resembles the slice next to it. But they were not the same Bob Wilson—they differed by a length of time.
When he had doubled back on himself, the difference had become apparent, for the separation was now in space rather than in time, and he happened to be so equipped as to be able to see a space length, whereas
1~°”~t~~ “t)
he could only remember a time difference. Thinking back he could re. member a great many different Bob Wilsons, baby, small child, adolescent, young man. They were all different—he knew that. The only thing that bound them together into a feeling of identity was continuity of memory.
And that was the same thing that bound together the three—no, four, Bob Wilsons on a certain crowded afternoon, a memory track that ran through all of them. The only thing about it that remained remarkable was time travel itself.
And a few other little items—the nature of “free will,” the problem of entropy, the law of the conservation of energy and mass. The last two, he now realized, needed to be extended or generalized to include the cases in which the Gate, or something like it, permitted a leak of mass, energy or entropy from one neighborhood in the continuum to another. They were otherwise unchanged and valid. Free will was another matter. It could not be laughed off, because it could be directly experienced—yet his own free will had worked to create the same scene over and over again. Apparently human will must be considered as one of the, factors which make up the processes in the continuum—”free” to the ego, mechanistic from the outside.