Virtual Immortality

Why the Mind-Body Problem is Still a Problem

BY ROBERT LAWRENCE KUHN

VIRTUAL IMMORTALITY IS THE THEORY THAT THE fullness of our mental selves can be uploaded with first-person perfection to non-biological media, so that when our mortal bodies die our mental selves will live on. I am all for virtual immortality and I hope it happens (rather soon, too). Alas, I don’t think it will (not soon, anyway). I’d deem it virtually impossible for centuries, if not millennia. Worse, virtual immortality could wind up being absolutely impossible, forbidden even in principle.

This is not the received wisdom of optimotechno-futurists, who believe that the exponential development of technology in general, and of artificial intelligence (AI) in particular (including the complete digital duplication of human brains in the near or mid term), will radically transform humanity through two revolutions. The first is the “singularity,” when AI will redesign itself recursively and progressively, such that it will become vastly more powerful than human intelligence (superstrong AI). The second, they claim, will be virtual immortality.

AI singularity and virtual immortality would mark a startling, transhuman world that optimotechno-futurists envision as inevitable in the long run and perhaps just over the horizon in the short run. They do not question whether their vision can be actualized; they only debate when will it occur, with estimates ranging from 10 to 100 years.

I’m skeptical. I think the complexity of the science is vastly underrated, and I challenge the philosophical foundation of the claim. Consciousness is the elephant in the room, though many refuse to see it. They assume, almost as an article of faith, that superstrong AI (post-singularity) will inevitably be conscious (almost ipso facto). They may be correct, but to make that judgment requires an analysis that is surely multifaceted and, I suspect, likely inconclusive.

Whatever consciousness may be, it determines whether virtual immortality is even possible. So I focus here on consciousness. First, however, there are two other potential obstacles to virtual immortality. I consider them briefly.

One is sheer complexity. What would it take to duplicate the human brain such that our first-per son inner awareness, and all that it entails, could not be distinguished from the original?

Consider some (very) rough data for the human brain: it contains about 85 billion neurons (specialized nerve cells that convey electrical information); 100 to 1000 trillion synapses (small space between neurons, the junction across which information is transmitted by neurochemicals); one to five trillion glial cells (traditionally assumed limited to metabolic support for neurons, now suspected as also participating in brain functions); up to 1000 moments per second for positioning action potentials (the electrical spark of information in neurons); ten billion proteins per neuron (some of which form memories); innumerable 3-dimensional structural forms for proteins and their geometric interactions; various extracellular molecules (some of which may be involved in brain functions). The list goes on.

How much of all of this complexity is required for total virtual duplication such that the mental fullness of the original person can be said to exist? Who knows?

Granted, not all of the brain is needed for consciousness and its contents, and much of the machinery is metabolic. The bodily control mechanisms, such as regulating breathing and heart rate and digestion, will not be needed in non-biological substrates. On the other hand, contemporary philosophy of mind suggests that bodily sense is needed for normal cognition (i.e., “embodied brain” and “extended mind”).

Take all the brain data together and consider all possible combinations and permutations that work to generate the more than 100 billion distinct human personalities who have ever lived (each of whom differs from moment to moment). I hesitate even to estimate the number of specifications that would be required. How could all these be accessed non-invasively, in sufficient detail, in real time, and simultaneously? The technologies exceed my imagination. But in principle, they are possible.

A second potential deterrent to virtual immortality is quantum mechanics, the inherent indeterminacies of which could make creating a perfect mental duplicate problematic or even impossible. After all, if quantum events (like radioactive decays) are in principle non-predictable, how then would it be possible to duplicate a brain perfectly?

But quantum indeterminacies exist everywhere, in bricks just as well as in brains, so its special applicability to brain function and hence to virtual immortality is questionable. The crux of the issue is at which level in the hierarchy of causation, if any, does quantum mechanics make meaningful contributions to brain function and to consciousness? Certainly the vast majority of neuroscientists think quantum mechanics works only at bedrock levels of fundamental physics, way too low to play any special role at the higher levels where brains work and minds happen.

So while the sheer complexity of the brain would deter virtual immortality, and the indeterminacy of quantum mechanics might be an insurmountable obstacle to perfect duplication, the former would only delay its advent while the latter is deemed not relevant.

That leaves consciousness—that elephant in the room—around which optimo-techno-futurists have gathered to plan their virtual afterlife.

What is Consciousness?

Consciousness is a main theme of Closer To Truth, my public television series on science and philosophy, and among the subtopics I discuss with scientists and philosophers on the program is the classic “mind-body problem”—what is the relationship between the mental thoughts in our minds and the physical activities in our bodies/brains? What is the deep cause of consciousness? (All quotes that follow are from Closer To Truth: www.closertotruth.com.)

NYU philosopher David Chalmers famously described the “hard problem” of consciousness: “Why does it feel like something inside? Why is all our brain processing —vast neural circuits and computational mechanisms—accompanied by conscious experience? Why do we have this amazing inner movie going on in our minds? I don’t think the hard problem of consciousness can be solved purely in terms of neuroscience.”

“Qualia” are the core of the mind-body-problem. “Qualia are the raw sensations of experience,” Chalmers continued. “I see colors—reds, greens, blues—and they feel a certain way to me. I see a red rose; I hear a clarinet; I smell mothballs. All of these feel a certain way to me. You must experience them to know what they’re like. You could provide a perfect, complete map of my brain [down to elementary particles]—what’s going on when I see, hear, smell—but if I haven’t seen, heard, smelled for myself, that brain map is not going to tell me about the quality of seeing red, hearing a clarinet, smelling mothballs. You must experience it.”