“Let’s try another one: how many of you have ever been reading a book—not one of mine, you understand, but somebody else’s—and gotten to the bottom of a page and realized you had no awareness of what the page said?”
Again, lots of hands went up.
“Okay, you might argue that driving a car is an example of what laypeople call muscle memory, although the technical term is ‘procedural memory’—stuff you do without thinking about it, like returning a serve in tennis or playing a musical instrument. But what about the reading example? Your eyes tracked across each successive line, and, on some level, your brain was presumably recognizing and processing the words. In fact, you can contrive priming tests to demonstrate that the words were noted. If the page referenced, say, a porcupine, and you’re asked, even though your mind wandered off while reading so you say you have no high-level conscious recollection of the page, to name a mammal, chances are you’ll say ‘porcupine.’ So, reading can’t be dismissed as just muscle memory, just your eyes tracking without actually seeing. And yet you can do it, too, without real attention.”
I let that sink in for a moment, then went on. “So, it’s clearly true that you can perform sophisticated acts without your full conscious attention some of the time. And, by logical extension, if you can do those things that way some of the time, then it’s presumably possible there are people who do them that way all of the time. Of course, we’d have no way to tell, would we? When you’re reading but not absorbing, nobody can tell that from the outside. And when you’re driving but not paying attention, again, well, if the police had a way of detecting that by some external sign—your eyeballs rolling up into your skull, say—you can bet they’d pull you over. But there is no external indication.”
I took a sip from the coffee cup on the lectern, then went on. “And that brings us to one of the most famous thought experiments in philosophy. Imagine a being who didn’t just drive all the time without paying attention, and who didn’t just read all the time without paying attention, but who in fact did everything all the time without attention. An Australian philosopher, David Chalmers, is the guy most associated with this proposal. He says it’s logically coherent—that is, there are no internal contradictions—to the notion that a whole planet could exist full of such entities: beings for whom the lights are on but nobody’s home, beings who are, quite literally, thoughtless.” Another sip, then: “Anybody got a suggestion for what we should call such creatures?”
I was always happy to set that one up, and my students never disappointed. “Politicians!” called out one. “Football players,” called another.
“Well,” I said, “almost anything would be an improvement over the term we actually use. Such beings are called ‘philosophical zombies’ or ‘philosopher’s zombies.’ It’s a terrible name: they’re not the walking dead, they don’t shamble along. Behaviorally, they’re indistinguishable from the rest of us. Sadly, the phrasing ‘philosophical zombie’ is more common in the literature than ‘philosopher’s zombie,’ but it doesn’t make sense: the one thing such creatures are unlikely to be is philosophical. Oh, they might say things a philosopher would—‘A could well follow from B,’ or ‘Yes, but how can we be sure your experience of red is the same as my experience of red?’ or ‘Would you like fries with that?’—but they’d only be acting like a philosopher. There would in fact be no inner life, no rumination. Me, I mostly avoid the zombie word. In the States, they can’t really abbreviate ‘philosopher’s zombie’ to its initials because it comes out sounding like ‘peasy,’ as in ‘easy-peasy.’ But here we can safely call them p-zeds, so let’s do that from now on.”
One of the students, a muscular guy named Enzo, raised his hand. “Well, then, Professor Marchuk, if all that’s true—if it really is possible—then how do we know you’re not a p-zed?”
“How indeed?” I replied, smiling beatifically at them all.
“We have to try again,” said Dominic firmly, on January 2, 2001.
“Are you insane?” replied Menno. “You saw what happened to that student, Jim Marchuk.”
“Which is precisely why we have to try again. We have exactly one data point now. We can’t draw any conclusions from that.”
“That boy might have died. What if he’d never regained consciousness?”
“But he did. And, really, we don’t even know that our equipment is what caused him to black out.”
“Oh, come on! It happened the moment we activated the helmet. What else could have caused it?”
“Who knows? Correlation is not causation. But, anyway, if the effect was unique to him, we need to know that. I’d hate to cancel a whole program based on one failure.”
“You know who else said that? General Turgidson in Dr. Strangelove—right before the world came to an end.”
“Don’t worry,” said Dominic. “It’ll be fine. We’ll be prepared this time. No fucking Laurel and Hardy carrying the body down the corridor. We’ll belt the next subject into the chair so he can’t fall out—don’t want a concussion! And if he does lose consciousness, well, we’ll just wait patiently. Marchuk revived in a matter of minutes, after all.” He thought for a moment. “Let’s try that business student, the runner. He had an inner monologue, too, and he’s from Winnipeg; he should be around. What was his name?”
“Huron,” Menno said reluctantly. “Travis Huron.”
“Okay, Travis,” said Menno into the intercom. “We want you to just think about the test message, all right? Just that, nothing else. Do you remember it?”
On the other side of the window, the athletic young man nodded. “‘Broadsword calling Danny Boy.’”
“Exactly. Just repeat that subvocally over and over once I say ‘go.’”
Another nod.
Menno had his finger poised over the enter key, but just stood there, unable to bring himself to press it.
After about ten seconds, Dominic, standing next to him, muttered, “Oh, for Christ’s sake,” reached over, and stabbed the other enter key on the numeric keypad, and—
—and Travis’s head tipped forward, and his strapped-in body sagged.
“Shit,” said Menno, rushing out the door and into the adjacent lab. He unstrapped the helmet and tossed it across the room to get it out of the way. It was just like with Jim Marchuk. Travis’s pulse was good—Menno had no trouble finding it this time—and his respiration was normal.
Dominic entered, too; Menno had run here, but Dominic must have fucking sauntered to take so long. “Well?” Dom said, as if inquiring about the score in a sporting event he didn’t really care about.
“Unconscious,” said Menno. “Otherwise fine… I guess.”
“It must be the transcranial focused ultrasound that makes them black out,” said Dom, “but I’m not sure why.”
“We shouldn’t have done this,” said Menno, feeling nauseated. He looked at his watch. “Two minutes.”
“It’ll be fine.”
Menno started to pace. “Damn, damn, damn.”
They waited… and waited… and waited, Travis breathing calmly the whole time, although a little drool had started to come out of his half-open mouth.