He even had an account from the database service which showed that he'd consulted the very same articles before.
He reread and replayed the news reports that he'd accessed from inside -- and found no discrepancies. He flicked through encyclopedic databases -- spot-checking random facts of history, geography, astronomy -- and although he was surprised now and then by details which he'd never come across before, there were no startling contradictions. The continents hadn't moved. Stars and planets hadn't vanished. The same wars had been lost and won.
Everything was consistent. Everything was explicable.
And yet he couldn't stop wondering about the fate of a Copy who was shut down and never run again. A normal human death was one thing -- woven into a much vaster tapestry, it was a process which made perfect sense. From the internal point of view of a Copy whose model was simply halted, though, there was no explanation whatsoever for its demise -- just an edge where the pattern abruptly came to an end.
But if the insight he'd gained from the experiments was true (whether or not they'd ever really happened) -- if a Copy could assemble itself from dust scattered across the world, and bridge the gaps in its existence with dust from across the universe . . . then why should it ever come to an inconsistent end? Why shouldn't the pattern keep on finding itself?
Or find a larger pattern into which it could merge?
The dust theory implied a countless number of alternative worlds: billions of different possible histories spelled out from the same primordial alphabet soup. One history in which Durham did run Copy number five -- and one in which he didn't, but was persuaded to take its place as a visitor, instead.
But if the visitor had been perfectly deceived, and had experienced everything the Copy did . . . what set the two of them apart? So long as the flesh-and-blood man had no way of knowing the truth, it was meaningless to talk about "two different people" in "two different worlds." The two patterns of thoughts and perceptions had effectively merged into one.
If the Copy had been allowed to keep on running after the visitor had learned that he was flesh and blood, their two paths would have diverged again. But the Copy had been shut down; it had no future at all in its original world, no separate life to live.
So the two subjective histories remained as one. Paul had been a visitor believing he was a Copy. And he'd also been the Copy itself. The patterns had merged seamlessly; there could be no way of saying that one history was true and the other false. Both explanations were equally valid.
Once, preparing to be scanned, he'd had two futures.
Now he had two pasts.
+ + +
Paul woke in darkness, confused for a moment, then pulled his cramped left arm out from under the pillow and glanced at his watch. Low power infrared sensors in the watch face detected his gaze, and flashed up the time -- followed by a reminder: due at landau 7 a.m. It was barely after five, but it hardly seemed worth going back to sleep.
Memories of the night before came back to him. Elizabeth had finally confronted him, asking what decision he'd reached: to abandon his life's work, or to forge ahead, now that he knew, firsthand, what was involved.
His answer seemed to have disappointed her. He didn't expect to see her again.
How could he give up? He knew he could never be sure that he'd discovered the truth -- but that didn't mean that nobody else could.
If he made a Copy, ran it for a few virtual days, then terminated it abruptly . . . then at least that Copy would know if its own pattern of experience continued.
And if another Paul Durham in one of the countless billions of alternative worlds could provide a future for the terminated Copy -- a pattern into which it could merge -- then perhaps that flesh-and-blood Durham would repeat the whole process
And so on, again and again.
And although the seams would always be perfect, the "explanation" for the flesh-and-blood human believing that he had a second past as a Copy would necessarily grow ever more "contrived," less convincing . . . and the dust theory would become ever more compelling.
Paul lay in bed in the darkness, waiting for sunrise, staring into the future down this corridor of mirrors.
One thing nagged at him. He could have sworn he'd had a dream, just before he woke: an elaborate fable, conveying some kind of insight. That's all he knew -- or thought he knew. The details hovered maddeningly on the verge of recollection.
His dreams were evanescent, though, and he didn't expect to remember anything more.
17
(Remit not paucity)
APRIL 2051
Maria shifted in her seat to try to get her circulation flowing, then realized it wasn't enough. She stood up and limped around the room, bending down to massage her cramped right calf.
She said, "And you claim you're the twenty-third?" She was almost afraid to sound too skeptical; not because she believed that Durham would take offence, but because the story was so strangely entrancing that she wasn't sure she wanted to deflate it, yet. One hint of mockery and the floodgates would open. "You're the twenty-third flesh-and-blood Paul Durham whose past includes all those who came before?"
Durham said, "I may be wrong about the exact number. I may have counted this last version more than once; if I'm capable of believing in twenty-three incarnations, some of them might be false. The whole nature of the delusions I suffered contributes to the uncertainty."
"Contributes. Isn't that a bit of an understatement?"
Durham was unflappable. "I'm cured now. The nanosurgery worked. The doctors pronounced me sane, and I have no reason to question their judgement. They've scanned my brain; it's functioning impeccably. I've seen the data, before and after. Activity in the prefrontal cortex --"
"But don't you see how absurd that is? You acknowledge that you were deluded. You insist that you're cured now. But you claim that your delusions weren't delusions --"
Durham said patiently, "I've admitted from the outset: my condition explains everything. I believed -- because I was mentally ill -- that I was the twenty-third-generation Copy of another Paul Durham, from another world."
"Because you were mentally ill! End of story."
"No. Because I'm certifiably rational now -- and the logic of the dust theory makes as much sense to me as ever. And it makes no difference whether my memories are true, false, or both."
Maria groaned. "Logic of the dust theory! It's not a theory. It can't be tested."
"Can't be tested by whom?"
"By anyone! I mean . . . even assuming that everything you believe is the truth: you've 'been through' twenty-three separate experiments, and you still don't know what you've proved or disproved! As you say: your condition accounts for everything. Haven't you heard of Occam's razor: once you have a perfectly simple explanation for something, you don't go looking for ever more complicated ways of explaining the very same thing? No dust theory is required." Her words reverberated in the near-empty room. She said, "I need some fresh air."
Durham said firmly, "After twenty-three ambiguous results, I know how to get it right this time. A Copy plus a virtual environment is a patchwork, a mess. A system like that isn't rich enough, detailed enough, or consistent enough, to be self-sustaining. If it was, when I was shut down, the entire VR world I was in would have persisted. That never happened. Instead -- every time -- I found a flesh-and-blood human with a reason to believe he shared my past. That explained my pattern of experience far better than VR -- even to the point of insanity.