But was not a theory of which all the elements were provably true a simple tautology? In the region of the unprovable, or even the disprovable, lay the only chance for breaking out of the circle and going ahead.

In which case, did the unprovability of the hypothesis of real coexistence—the problem which Shevek had been pounding his head against desperately for these last three days, and indeed these last ten years—really matter?

He had been groping and grabbing after certainty, as if it were something he could possess. He had been demanding a security, a guarantee, which is not granted, and which, if granted, would become a prison. By simply assuming the validity of real coexistence he was left free to use the lovely geometries of relativity; and then it would be possible to go ahead. The next step was perfectly clear. The coexistence of succession could be handled by a Saeban transformation series; thus approached, successivity and presence offered no antithesis at all. The fundamental unity of the Sequency and Simultaneity points of view became plain; the concept of interval served to connect the static and the dynamic aspect of the universe. How could he have stared at reality for ten years and not seen it? There would be no trouble at all in going on. Indeed he had already gone on. He was there. He saw all that was to come in this first, seemingly casual glimpse of the method, given him by his understanding of a failure in the distant past. The wall was down. The vision was both clear and whole. What he saw was simple, simpler than anything else. It was simplicity: and contained in it all complexity, all promise. It was revelation. It was the way clear, the way home, the light.

The spirit in him was like a child running out into the sunlight. There was no end, no end…

And yet in his utter ease and happiness he shook with fear; his hands trembled, and his eyes filled up with tears, as if he had been looking into the sun. After all, the flesh is not transparent. And it is strange, exceedingly strange, to know that one’s life has been fulfilled.

Yet he kept looking, and going farther, with that same childish joy, until all at once he could not go any farther; he came back, and looking around through his tears saw that the room was dark and the high windows were full of stars.

The moment was gone; he saw it going. He did not try to hold on to it. He knew he was part of it, not it of him. He was in its keeping.

After a while he got up shakily and lighted the lamp. He wandered around the room a little, touching things, the binding of a book, the shade of a lamp, glad to be back among these familiar objects, back in his own world—for at this instant the difference between this planet and that one, between Urras and Anarres, was no more significant to him than the difference between two grains of sand on the shore of the sea. There were no more abysses, no more walls. There was no more exile. He had seen the foundations of the universe, and they were solid.