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Personal Identity
Teletransportation
(Text as at 26/11/2007 23:25:26)
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A Case Study - “Beam me up Scottie”: There are two obvious supposed mechanisms for teletransportation:
- Transferring both matter and information; or simply
- Transferring information, utilising local matter.
I gather that in the show itself, it's plasma that's transmitted, but as this is unlikely to get to its destination without causing havoc, the information-only transfer is more reasonable. However, even in the plasma-transfer case, I'm unconvinced that I'd survive1, for two reasons:
- Some things (eg. bicycles) can survive disassembly and re-assembly, but only if they are disassembled into recognisable parts. If a bicycle is disassembled into iron filings and latex goo, and then re-manufactured, we might be reluctant to say it's the same bicycle.
- As a matter of empirical fact, fundamental particles are not distinguishable, so the labelling cannot be undertaken even in principle. If it doesn't matter which particle fits where, provided they are of the right sort, the case seems to collapse into the information-transfer variant.
We now turn to the information-transfer case. My main worries initially here have to do with the possibility of duplicates2. We all know that a counterfeit, however well done, isn't the same as the original. The logic of identity3 is constraining. A thing is identical to itself and to nothing else, so if a thing is identical to two "other" things, these "two" must be identical to one another. Given that my two beamed-up versions aren't identical to one another, at least one of them can't be identical to me. And, since they are exactly similar4, why choose one rather than the other? So, neither is me. Both are exactly similar to me, but identity is to be distinguished from exact similarity. This situation is similar to the case where the "original" human being isn't destroyed. This sort of thought experiment5 is referred to as the branch-line case. Canonically, it's where I've only a few days left to live (because the scanner has done me a mischief). Would I be happy in the knowledge that my duplicate would go on and on, and take up with my partner and career where I left off? Is this as good as if I survived? Not likely, unless we’re Parfitian6 saints! Note, however, that the case is tendentiously described (ie. as teletransportation) to lead to this seemingly obvious conclusion. The "main line" candidate would be perfectly happy that his rival back home was about to perish.
Philosophers split into two main camps in response to these situations (though - jumping ahead a little - even if perdurantism7 is true, we still might not have the teletransportation of a persisting8 individual9, because of the wrong sort of causal10 link leading to a lack of forward continuity11 of consciousness12, or even of physical continuity). So there are multiple bifurcations, but we keep things simple here and just follow those who think that I either survive or have what matters13 in survival:-
- 4-dimensionalists (Perdurantists): A thing is really a 4-dimensional worm through space-time, which consists in a set of instantaneous 3-D stages. In this situation, where multiple teletransportations occur, all copies are me. They are different 4-D worms, but they share all their pre-beaming-up stages. There were always at least 2 people present.
- 3-dimensionalists (Endurantists) claim that while I'm not identical to the beamed-up person, yet I have what matters in survival.
Note that there's a modal14 argument to the effect that even in the usual case where only one copy is beamed up, and the original is destroyed, because there might have been multiple copies, this means that identity isn't preserved even in the case where there's only one teletransportation-result created. This seems to lead to paradox. Imagine the situation - I'm beamed up and think I've survived, and am then told that the machine has malfunctioned and produced a duplicate, and hence, contrary to my experience, I haven't survived after all! Unfortunately, some philosophers go along with a "closest continuer15" theory of identity across nasty cases of fission16 or fusion17. I'm identical to (or even “survive as”) the continuer that most closely continues me, either psychologically18 or physically19, according to taste. How can my survival depend on what happens to someone else, the thought goes? While this does seem odd, in fact you can’t trust the feelings of the teletransportees – for even if multiple copies are made, they all subjectively feel like the original.
There are two questions outstanding.
- Do I survive the transfer? And, if I don’t,
- Does it matter that I'm not identical to the post-beamed person?
I’m here ignoring the (as it seems to me20) illogical “survival without identity” option.
We have seen that it is possible that it appears to me that I survive, yet I do not. On the endurantist view, the logic of identity means that I cannot trust my experience. So, it seems possible that the person “waking up” is not me. I never wake up – in the sense that I lose consciousness, but never experience a re-awakening - but someone else with my past in his memories is created in my stead.
So, is survival what matters? Well, on the perdurantist view, it’s not even sufficient for me to have what matters. Imagine the case where the machine goes haywire and 1,000 exactly similar teletransportees are created. All these share my pre-teletransportation stages, so are all me (except that “I” was always 1,000 co-located individuals – and maybe more – who knows how often the machine may go wrong in the future!). In this case 1,000 individuals would be squabbling over the same friends, relations, job etc, and that might be rather a nuisance. However, this isn't fundamental to whether I do or don't survive. If I'm a violin virtuoso or a body-builder, I might not find it much fun surviving as a brain in a vat, but that would just be tough. The standard philosophical test is the "future great pain test". I believe that the future continuant will be me, whether I like it or not, if I'm as terrified of that continuant being tortured as I would be if I were to be tortured in the normal course of events. Our BIVs21 would be even more upset at the prospect of torture-simulation being fed into their brains than at the loss of their beautiful bodies. Our fears have to be moderated by logic, however. But this is no worse than ignoring a revivalist rant on Hellfire. If I’m not identical to a particular teletransportatee, I won’t survive, and if I don’t survive I won’t feel anything. I may have a moral obligation not to land others in a pickle, but it won’t be the selfish problem of avoiding landing myself in one.
I can imagine fissioning, by the bungled-beaming-up process, into 1,000 continuants, none of which (on a 3-D view) is identical to me, but all of whom seem to themselves to continue my first-person perspective. I can imagine (just about) going into the machine, and coming out again 1,000 times (when the life-histories of the 1,000 then start to diverge). While the psychologies of the 1,000 are initially identical, they are not connected to one another, though they are each connected continuously to the pre-beamed-up person. So, if even one of them were to be threatened with torture, I'd be terrified if I thought that that one (even amongst all the others) would be me, in the sense that my experience continues into that body.
But, do I survive? I don't think I do, for reasons given above. It’s not that I reject perdurantism, it’s just that even accepting perdurantism there’s too radical a discontinuity. It's clear that a duplicate, looking backwards, wouldn't be able to tell apart the situation from the normal one of (say) just having woken up after a dreamless sleep. However, I imagine it's possible (even in a supposedly successful teletransportation) for there to be nothing it's like for me after the beaming - it's as though I never woke up, though someone else woke up thinking he was me. This would be a tragedy but, we'd never know about it, because (on this hypothesis) I wouldn't be around to tell the tale, and my duplicate would claim everything was fine (he remembered going to bed and waking up, as it were).
This worries me slightly about our every-night bouts of unconsciousness. How do I know that “the me” that wakes up is “the same me” that went to sleep, and would it matter if it wasn't? Was my mother right in saying “it’ll be all right in the morning”, in the sense that I’d have no further experience of the current problem, or indeed of anything at all? Is this worry parallel to beam-me-up case? Or is sleep a pain-free death?
I suspect the answer to these questions is that for a physical thing to persist, there needs to be appropriate physical continuity, and this continuity guarantees its persistence (though this intuition is a bit of a feeble response). On the assumption that my brain22 supports my conscious experience, this is enough to reassure me that, as it's the same continuing brain in my skull overnight, it's the same me that's conscious in the morning. I don't have the same reassurance in the case of beaming-up. So, I wouldn't go in for it, even if it came to be seen as a cheap form of transportation.
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