I’ve been browsing the “World Question Centre ” at edge.org, the website for thinking folk with time on their hands. The 2005 Edge question is a good one: “What do you believe is true even though you cannot prove it?”
Alexander Vilenkin, a physicist, believes that our universe is just one of an infinite number of similar regions. But “it follows from quantum mechanics” that the number of histories that can be played out in them is finite. The upshot of this crossplay of finitudes and infinities is that every possible history will play out in an infinite number of regions, which means there should be an infinite number of places with histories identical to our own down to the atomic level. “I find this rather depressing,” says Vilenkin, “but it is probably true.” The cognitive scientist Donald Hoffman, on the other hand, believes that “consciousness and its contents are all that exists,” the physical universe being “among the humbler contents of consciousness.” But he can’t prove that either. Daniel Dennett sees consciousness as a scarcer commodity. His unproven belief is that, lacking language, animals and pre-linguistic children also lack self-awareness. He insists that neither is thereby morally demoted, but, I wonder, does this mean it is more acceptable to eat small children or less acceptable to eat animals?
This brings us to death. The psychologist Jesse Bering believes we will never get our heads around the idea. He calls it “Unamuno’s paradox,” after the Spanish existentialist Miguel de Unamuno, who was troubled not so much by the prospect of his own death as by his inability in life to get any kind of imaginative purchase on what the state of being dead would be “like.” “The effort to comprehend it causes the most tormenting dizziness,” he lamented. And you can’t get out of this by saying that “it is like nothing at all” to be dead, because the point is precisely that we are incapable of imagining absolute nothingness. Our mental apparatus is tuned to states of being in the world. Non-being is simply beyond our ken. All of this is of no concern to those who believe in an afterlife. The conscious personality just floats on elsewhere. That most people hold to this bizarre belief is not simply due to religious indoctrination. The separateness of body and mind is a primordial intuition. It has sprung from our evolution as social beings and coalesced into the hardware of the central nervous system. Human beings are natural born soul makers, adept at extracting unobservable minds from the behaviour of observable bodies, including their own. Taking the next, false step, if mind and body are conceived as separate entities, it is easy to see the possibility of a mental life after physical death.
This leads me to “Broks’s paradox”: we are inclined to believe in mind-body dualism even though we understand it to be wrong. Neuroscientists are not exempt. Consider the following thought experiment, devised by the philosopher Derek Parfit. Some years hence you find yourself taking business trips to Mars. Teleportation is the usual mode of transport. It works like this. A scanner records the states of your body in atomic detail and digitally encodes the information for radio transmission. Your body is destroyed in the process but reconstructed on Mars using locally available materials as soon as the radio signals are decoded. The replication is perfect: identical body and brain, identical memory stores and patterns of mental activity. It is “you.” You are in no doubt. Most neuroscientists say they would readily submit to this process. Why should they worry about destruction and reconstruction of the body? As good materialists, they know that “the self” (secular cousin to the soul) is no more than a pattern of experiences and dispositions bundled together by the operations of the central nervous system. Now imagine this. There is a teleporter malfunction. You have been scanned and the information transmitted, but this time your body was not vaporised in the usual way. Your replica was automatically constructed and is going about its business. Worse still, the faulty scanner has left you with a fatal heart condition. You will be dead within days. Which would you rather be, the Martian replica or the moribund earthbound version? It should make no difference to a true materialist. In scenario two, the vaporisation process has been delayed, that is all. The personal trajectory of the individual arriving on Mars is the same for both scenarios. Psychological continuity has been maintained, as it is via the oblivion of sleep from one ordinary day to the next. But very few rest easy with scenario two. It shatters one’s complacency about unproblematic teleportation (and therefore materialism): “If the replica’s not me now…”
One might dismiss all this as “angels on a pinhead” stuff. But Ian McEwan” makes a telling point. “What I believe but cannot prove,” he says, “is that no part of my consciousness will survive my death.” His enlightened fellow Edge contributors will take this as a given, but they may not appreciate its significance, which is that belief in an afterlife “divides the world crucially, and much damage has been done to thought as well as to persons by those who are certain that there is a life, a better, more important life, elsewhere.” The natural gift of consciousness should be treasured all the more for its transience.