Last week I Twittered/Facebooked some provocative results from a poll of philosophers. In particular, this little tidbit:
Teletransporter (new matter): survival or death?
Accept or lean toward: survival 337 / 931 (36.1%) Other 304 / 931 (32.6%) Accept or lean toward: death 290 / 931 (31.1%)
Yes, that’s all the detail presented in the question: “Teletransporter (new matter): survival or death?” As a professional philosopher, you’re supposed to be familiar with the issue, which I reconstruct as follows. Imagine that someone has invented a working teleportation device. You step in the box, lights flash and sparks fly, and “you” rematerialize in another box, exactly the same in every way, but constructed out of a completely new collection of atoms. The original version of you is destroyed. Did you die? (And then, what if a million years passed in between the two events?)
It would probably be annoying to real philosophers, but I personally put this question in the category of “Not that hard.” And I would phrase my answer as: “Who cares?” What we should care about is how well the teleporter actually works — is the reconstructed person really in exactly the same quantum state as the original one was in? Same memories, feelings, etc? That’s an interesting technology question.
But there’s no interesting question associated with “Did you really die when you were teleported?”, or “Are you really the same person after being teleported?” These are just bad questions. They assume a certain way of looking at the world that ceases to be useful once we’ve invented teleportation. Namely, they assume that there’s a certain “essence of you-ness” that is (somehow) associated with your physical body and continues through time. That’s a perfectly sensible way of talking in the real world, where we don’t have access to duplicator devices or transporter machines. But if we did, that conception would no longer be very useful. There is a person who stepped into the first box, and a person who stepped out of the second box, and obviously they have a lot in common. But to sit down and demand that we decide whether they are “really” the same person is just a waste of time — there is no such “really.”
Which isn’t to say there aren’t interesting questions along these lines, but they are operational questions — how should I actually act, or what should I actually expect to happen, in these situations? — rather than arid metaphysical ones. What if you murdered someone, and then teleported — would the reconstructed person still be guilty of murder? That’s not quite the right question, because it still relies on the slippery essence of continuous personhood, but there’s a closely related sensible question — should we treat the reconstructed person as if they had committed murder? And it seems to me that the answer is clearly “yes” — whatever good reasons we had for treating the pre-teleportation person in a certain way, those reasons should still apply to the post-teleportation person.
The issue of duplication seems much thornier to me than the issue of teleportation. If someone made an exact copy of a known murderer, should we treat both the original and the copy as murderers? (I vote “yes.”) Fine, but what about the view from the inside? Let’s say you have an offer to get paid $100 if you let yourself be copied, with the proviso that after being copied one of the two of you will randomly be chosen for immediate painless execution. Do you take that deal?
I think problems like that are legitimately interesting, although to a great extent their mystery relies on the inadequacy of our conceptions of death. Most of us don’t want to die, at least not right away. But if we did die, we’d be gone, and wouldn’t have any wants or desires any more — but it’s very hard to consistently reason that way. Note that if we replaced “immediate painless execution” with “prolonged torture,” it seems like a much more straightforward question.
This showed up in our long-ago discussion of the quantum suicide experiment. In the many-worlds interpretation of quantum mechanics, you can make measurements that split the wave function of the universe into distinct branches. In some sense, then, you really do have a duplicator machine — it’s just that the whole universe gets duplicated, not just you. Some folks have tried to argue against this idea by pushing adherents into a logical cul de sac. You shouldn’t (to make a long story short) be averse to bargains that leave you dead with large probability, as long as there exist branches of the wave function where you are alive and flourishing — after all, in the branches where you are dead you don’t care any more, right?
My point in that earlier post — a point I somehow managed to completely obscure — was that these are misleading thought experiments, because very few of us would take seriously the corresponding classical suicide experiment. “Here, I’ll flip a coin, and give you $100 if it’s heads and shoot you instantly dead if it’s tails. Deal?” Very little temptation to take that offer. But the logic is essentially the same — if you’re dead you don’t care, right? (For purposes of these thought experiments we always assume you have no friends or loved ones who would miss you; it’s just part of the philosophical game, not a comment on your actual social situation.)
At some point in thinking about the many-worlds interpretation, issues like this inevitably do come up. That’s what David Albert and I talked about a bit on Bloggingheads. There might be a certain measurement that yields result A 10% of the time, and result B 90% of the time. But in the MWI, the measurement splits the universe into two branches, and you end up either in the branch where you saw A or the branch where you saw B. What does it mean to say that you had a “10% chance of measuring A”? You either did or you didn’t — there is no ensemble of millions of you all doing the same experiment. People have made progress on these questions — here’s a talk by David Wallace on his work with David Deutsch in attacking this problem. (Don’t ask me why everyone who thinks about these issues is named “David.”) I haven’t ever looked at this work closely enough to have an informed opinion.
All I know is that being able to teleport around would be really cool.
@LM,WI (#34) – what you’re “missing” is the concept of continuity. If you walk across the room, there is no break in continuity of the existence of ‘you’. However, if your physical being is destroyed after having a blueprint stored in a computer, and then reproduced from entirely different matter, there is a “break” in your physical existence (though some philosophers argue that your physical continuity is still whole, it just changed form from matter into an electrical pattern or however you describe the blueprint in the computer, and then back to matter again). And then there is the question of the continuity of the mind, which is a similar issue, unless you don’t cotton to the idea of the mind being purely physical, which makes it quite a bit more complicated.
This is a bit reductionistic for my taste. I prefer a more gestalt view of the human experience beyond the sum of the atoms that comprise us.
…Also, I’m 90% sure that the duplicate of me would be a lot bigger jerk than I am.
A short story from some years ago: In the sufficiently-distant future, a young couple marry and book passage on the latest thing, a teleporter that lets them spend their honeymoon on the Moon. Returning after a wonderful experience, they happily settle into discovering married life.
Six months later she is killed in an accident. He is devastated, but eventually learns from a friend in the teleportation industry that in peak periods passengers are sometimes recorded for later transmission.
Their records are still available; the friend pulls strings and gets her reconstituted. The groom is ecstatic, of course, but discovers that she has no memory of the honeymoon, of their time together, or of course the accident. The marriage breaks up.
The story would have been even more poignant if they had had a three-year-old child at the time of her death.
What does it mean to say I would be made up of “different” matter if every atom in my body had the same state as before? Also, as for continuity, what’s so special about that? I know it’s giga-highly unlikely, but every atom in my body might suddenly tunnel to another spot ten feet away. Did I die? Am I different?
I made a similar (although differently-emphasized) post on my dusty blog back in January. (http://sgx2.sgdragons.com/2009/01/14/immortality/) I come down on the site of the original consciousness dies during any sort of teleportation. Sean, you think it’s a bad question to decide if the original is experiencing death or not, but I feel it’s a key question – unless and until a non-atomic consciousness (i.e., “soul”) is proven, and a mechanism for transporting such soul separately from the atoms which make up our “meat,” then the experience of the original body during any sort of teleportation is a key question.
What does it mean to say I would be made up of “different” matter if every atom in my body had the same state as before?
Possibly nothing. That’s why this sort of philosophy is known as metaphysics 🙂
Also, as for continuity, what’s so special about that?
Again, possibly nothing. It is an older concept that may or may not be relevant since the development of quantum theories.
To the question “who cares?” the answer is “the person being ‘teleported.'” According to the “survival” view, I walk into the teleportation booth, someone presses a button, and I step out on Mars. According to the “death” view, I walk into the teleportation booth and that’s the last thing I ever do. A duplicate will step out on Mars, but I won’t experience any of the things that duplicate experiences, because I will have been annhiliated.
In the story “Think Like a Dinosaur” by James Patrick Kelly, there is a teleportation station which operates as follows: the person to be teleported is rendered unconscious; all the information about her is sent to her destination, where she is reconstructed; and then the original is killed, while still unconscious. The part about the original being killed is kept secret. In the story there is a screw-up and the original wakes up after being teleported, but the aliens who run the network as a whole insist that the human operator of the station kill her.
I’m not sure if this was said earlier in the comments (because I didn’t look at them…), but generally this problem IS viewed as the problem of duplication; the destruction of the original body is like a variation of the “coin-flip of death” (you win you get a hundred dollars, you lose you die). I completely agree that though the duplication problem is extremely interesting. It seems that if you allowed the original body to survive most people would say that that one is still “you,” simply because of continuity. I think though that body that comes out on the opposite end is also “you”; in every single way, that other body would believe itself to be “you.”
I think a related question also is the “Ship of Theseus”: if you have a ship and once every year you replace one plank of wood or part until finally no original parts are left, is it the same ship? If you believe that it is, then you should therefore think that the “new” person is definitely “you” ,
I’m not sure if this was said earlier in the comments (because I didn’t look at them…), but generally this problem IS viewed as the problem of duplication; the destruction of the original body is like a variation of the “coin-flip of death” (you win you get a hundred dollars, you lose you die). I completely agree that though the duplication problem is extremely interesting. It seems that if you allowed the original body to survive most people would say that that one is still “you,” simply because of continuity. I think though that body that comes out on the opposite end is also “you”; in every single way, that other body would believe itself to be “you.”
I think a related question also is the “Ship of Theseus”: if you have a ship and once every year you replace one plank of wood or part until finally no original parts are left, is it the same ship? If you believe that it is, then you should therefore think that the “new” person is definitely “you” , and if you think it is a new ship than you should think that the “new” person is indeed a new person. That in itself is a whole ‘nother debate though isn’t it?
For me, it is very difficult to decide whether or not it is something you should “who cares?” about; it perhaps is not relevant, but that does not mean you should not care. In fact, that’s a whole different debate isn’t it? I think you could spend ages just debating whether or not you should. Most philosophers say they are awful at finding out the truth, just good at asking questions and I think this is a good example.
The whole continuity of self question has so many different explanations, and some of them are definitely the religious metaphysical views… Another interesting thing to think about is the nature of the mind in this situation… whether it is the “software of the brain,” just the brain, or completely separate.
Sorry if I was vague at all I’m pretty undecided on this one (which I think is totally fine… I think that most philosophers are undecided about most things…). I think that it is good to just lay out all the views.
P.S. This blog is the best… How many blogs talk about astrophysics and Philosophy of the Self?
P.P.S. Can’t wait for your book… definitely buying it.
The topic reminds me of the movie, The Prestige, where the magician, played by Hugh Jackman, has to kill off a “copy” of himself every time he performs a very special magic trick. Of course, his first performance of the trick took his own life…uh…well, I mean…uh…his original life…oh, what difference does it make? 🙂
Great blog, Sean! And I recommend to everyone your “The Teaching Company” course on cosmology. Excellent!!