“I know just enough about it to know that what you just said has been controversial for a long, long time.”

This affected him not at all; but after I looked in his eye long enough, he finally gave a shrug. So be it. “Did Sammann ever talk to you of Saunt Grod’s Machines?”

“No. What is it?”

“A syntactic device that made use of quantum theorics. Before the Second Sack, his forerunners and ours worked together on such things. Saunt Grod’s Machines were extremely good at solving problems that involved sifting through many possible solutions at the same time. For example, the Lazy Peregrin.”

“That’s the one where a wandering fraa needs to visit several maths, scattered randomly around a map?”

“Yes, and the problem is to find the shortest route that will take him to all of the destinations.”

“I kind of see what you mean,” I said. “One could draw up an exhaustive list of every possible route—”

“But it takes forever to do it that way,” Orolo said. “In a Saunt Grod’s Machine, you could erect a sort of generalized model of the scenario, and configure the machine so that it would, in effect, examine all possible routes at the same time.”

“So, this kind of machine, instead of existing in one fixed, knowable state at any given time, would be in a superposition of many quantum states.”

“Yes, it’s just like an elementary particle that might have spin up or spin down. It is in both states at the same time—”

“Until someone observes it,” I said, “and the wavefunction collapses to one state or the other. So, I guess with a Saunt Grod’s Machine, one eventually makes some observation—”

“And the machine’s wavefunction collapses to one particular state—which is the answer. The ‘output,’ I believe the Ita call it,” Orolo said, smiling a little as he pronounced the unfamiliar bit of jargon.

“I agree that thinking often feels that way,” I said. “You have a jumble of vague notions in your mind. Suddenly, bang! It all collapses into one clear answer that you know is right. But every time something happens suddenly, you can’t simply chalk it up to quantum effects.”

“I know,” Orolo said. “Do you see where I’m going, though, when I speak of counterfactual cosmi?”

“I didn’t really get it until you brought quantum theorics into the picture,” I said. “But it’s been obvious for a while that you have been developing a theory about how consciousness works. You have mentioned some different phenomena that any introspective person would recognize—I won’t bother to go back and list them all—and you have tried to unify them…”

“My grand unification theory of consciousness,” Orolo joked.

“Yes, you are saying that they are all rooted in a special ability that the brain has to erect models of counterfactual cosmi in the brain, and to play them forward in time, evaluate their plausibility, and so on. Which is utterly insane if you take the brain to be a normal syndev.”

“Agreed,” Orolo said. “It would require an immense amount of processing power just to erect the models—to say nothing of running them forward. Nature would have found some more efficient way to get the job done.”

“But when you play the quantum card,” I said, “it changes the game entirely. Now, all you need is to have one generalized model of the cosmos—like the generalized map that a Saunt Grod’s Machine uses to solve the Lazy Peregrin problem—permanently loaded up in your brain. That model can then exist in a vast number of possible states, and you can ask all sorts of questions of it.”

“I’m glad that you now understand this in the same way that I do,” Orolo said. “I do have one quibble, however.”

“Oh boy,” I said, “here goes.”

“Traditions die hard, among the avout,” Orolo said. “And for a very long time, it has been traditional to teach quantum theorics to fids in a particular way that is based on how it was construed by the theors who discovered it, way back in the time of the Harbingers. And that, Erasmas, is how you were taught as well. Even if I had never met you before today, I would know this from the language that you use to talk about these things: ‘it exists in a superposition of states—observing it collapses the wavefunction’ and so on.”

“Yes. I know where you are going with this,” I said. “There are whole orders of theors—have been for thousands of years—that use completely different models and terminology.”

“Yes,” Orolo said, “and can you guess which model, which terminology, I am partial to?”

“The more polycosmic the better, I assume.”

“Of course! So, whenever I hear you talking of quantum phenomena using the old terminology—”

“The fid version?”

“Yes, I must mentally translate what you’re saying into polycosmic terms. For example, the simple case of a particle that is either spin up or spin down—”

“You would say that, at the moment when the spin is observed—the moment when its spin has an effect on the rest of the cosmos—the cosmos bifurcates into two complete, separate, causally independent cosmi that then go their separate ways.”

“You’ve almost got it. But it’s better to say that those two cosmi exist before the measurement is made, and that they interfere with each other—there is a little bit of crosstalk between them—until the observation is made. And then they go their separate ways.”

“And here,” I said, “we could talk about how crazy this sounds to many people—”

Orolo shrugged. “Yet it is a model that a great many theors come to believe in sooner or later, because the alternatives turn out to be even crazier in the end.”

“All right. So, I think I know what comes next. You want me to restate your theory of what the brain does in terms of the polycosmic interpretation of quantum theorics.”

“If you would so indulge me,” Orolo said, with a suggestion of a bow.

“Okay. Here goes,” I said. “The premise, here, is that the brain is loaded up with a pretty accurate model of the cosmos that it lives in.”

“At least, the local part of it,” Orolo said. “It needn’t have a good model of other galaxies, for example.”

“Right. And to state it in the terminology of the old interpretation that fids are taught, the state of that model is a superposition of many possible present and future states of the cosmos—or at least of the model.”

He held up a finger. “Not of the cosmos, but—?”

“But of hypothetical alternate cosmi differing slightly from the cosmos.”

“Very good. Now, this generalized cosmos-model that each person carries around in his or her brain—do you have any idea how it would work? What it would look like?”

“Not in the slightest!” I said. “I don’t know the first thing about the nerve cells and so on. How they could be rigged together to create such a model. How the model could be reconfigured, from moment to moment, to represent hypothetical scenarios.”

“Fair enough,” Orolo said, holding up his hands to placate me. “Let’s leave nerve cells out of the discussion, then. The important thing about the model, though, is what?”

“That it can exist in many states at once, and that its wavefunction collapses from time to time to give a useful result.”

“Yes. Now, in the polycosmic interpretation of how quantum theorics works, what does all of this look like?”

“There is no longer superposition. No wavefunction collapse. Just a lot of different copies of me—of my brain—each really existing in a different parallel cosmos. The cosmos model residing in each of those parallel brains is really, definitely in one state or another. And they interfere with one another.”

He let me stew on that for a few moments. And then it came to me. Just like those ideas we had spoken of earlier—suddenly there in my head. “You don’t even need the model any more, do you?”

Orolo just nodded, smiled, egged me on with little beckoning gestures.