Hmmm...the first thing that comes to mind is that the English common law -- and thus current American law based on it as well -- didn't evolve to deal with dopplegangers. As currently constituted, our law does not have anything in place to address property rights which might belong to two identical persons arising from the same original identity. Our law has never had to deal with dopplegangers, and it would have to change radically in order to accommodate their existence.
AS
Hey, AS - Thanks for coming here and helping out.
I understand that you claim that the two persons do not share the same identity, as you attach some temporal significance to the "original" versus the "copy," but I'm much more inclined to go with Huntsman's pure materialist view. I think your 4th dimension distinction is artificial and without substance, as a materialist viewpoint would incorporate time into space-time, as time t is just as physical as the three spatial dimensions x, y, and z. Therefore, a perfect copy of an original would share the same temporal characteristics. In other words, it would have the same history as the original up until the moment of duplication (although it really isn't possible to make a perfect copy of you in N dimensions, because each of you will occupy different co-ordinates in N-space). Remember, however, that this is a thought experiment.
This is a separate issue, but I have a question for you. Isn't your use of the term "replicant" loaded? Your apparent usage implies that the original and the copy are indeed distinguishable. One of them has the physical property or quality of "originalness," and the other doesn't. How can originalness be a physical property of hairless atoms arranged in N-space? If it isn't, then you are proposing a dualist paradigm, aren't you?
Yes, it's loaded... I used the term replicant specifically because I was taking the position that the two individuals aren't the same person and that there are physical aspects to both of them that are unique, no matter how they're created.
I maintain that duration
is a physical property of systems (i.e., humans) in the universe - and that is one of the properties that differentiates the two. Spatial location at the time of creation and afterwards is a second property, IMO - so from my perspective, this means that there are two physical properties for the original and the replicant that are unique. Again, IMO, this is as true for individual atoms as is it for systems. I don't see why the act of transportation would carry over the temporal property of the original (i.e., history); after all, it doesn't carry over the spacial coordinates, which is another property of the original at time of transport as well. (Unless someone wants to argue that non-quantum spacial location and duration of things aren't a physical property of a given object. I'd like to hear the science behind
that position.

)
As pointed out, an atom has no hair; well, neither does a black hole. However, we differentiate between them - "This atom and that atom" and "This black hole and that black hole" with no problem whatsoever on a routine basis due to location and duration of both. So I don't see why the hairlessness of atoms constitutes a decisive argument here.
Anyway, if I'm proposing a dualist paradigm, I'm not doing so on purpose; I believe I'm presenting a pertinent physical aspect of the situation that's being dismissed. I could be wrong, though - maybe I am being dualist. We'll see.
Transitory relief from whom? The "original?" If so, which one is the original? There is no physical way to tell. I'm not buying your continuity argument, because I think it's another way of assuming a dualistic universe. I agree with Huntsman 100% on this issue. There is no continuity of "you," because atoms are fungible, and because the atoms constituting you are continually being exchanged with other atoms you expell through your breath, your sweat, your waste, and those you ingest by breathing, eating, and by having your skin come into contact with air and surfaces and plants and animals, etc. The atoms constituting you today were not in your body 30 years ago.
Therefore, if "you" are simply a configuration of atoms, then a duplicate of you is possible to construct merely by arranging a different, but indistinguishable set of atoms in exactly the same configuration (ignoring the impossibility of occupying the same co-ordinates in N-space problem for the sake of argument). Which "you" is required to provide transitory relief to the other?
Fair enough, although I don't agree with your response on this for the reasons given above. In the example, the original remains at the point of origin while the replicant (yeah, I
am going to use that word again!

) appears at a different location. This makes it trivial to separate the two at the instant of transfer - and if they're kept separate, it also makes it easy to distinguish them going forward. (As in one is on Mars and the other on Earth, for example.)
Additionally, any physical procedure (dental work, tattoo, whatever) done to either one of our hypothetical people would be enough to differentate them going forward. (Always assuming that they both didn't get the identical procedure.)
The difficulty in differentation only happens if the two are brought together unobserved and unrecorded with no change to the original or replicant to separate them... or if the replicant is created in the same chamber (again, unobserved and unrecorded) with the original.
Then it would be impossible for us to determine which one was which,
assuming our abilities in the thought experiment remain the same as they are in the real world.
An inability to determine the difference is a lack of technology on our part, however, and not - IMO - a built-in characteristic of the two. if we go back to my assertion that duration and spacial location are two physical aspects that are not being considered here, this suggests a solution to the problem of detection.
Snce we are postulating the ability to perfectly - and
instantly - duplicate someone, we are ignoring the physical laws in our thought experiment. That's fine, for purposes of our discussion.
Since we're breaking physical laws anyway, it's only fair to allow me to postulate a mechanism for viewing duration and spacial location - such as a "visual time machine", for example. The kind of machine I'm proposing would allow us to voyueristically view every moment of anyone's life, from birth to the current moment... thereby providing a contiguous view of that individual's duration and spacial location at all times. Clearly this would provide the ability to differentiate between the two.
Not to beat the point to death - but to clarify - I believe dismissing duration and spacial location as characteristics here would be seriously problematic for this thought experiment. In doing so I think we'd be creating a universe so alien that it bears little physical resemblance (sp?) to our own... which invalidates the thought experiment, IMO.
I haven't thought it through fully, but dismissing those two characterstics might also affect causality as well.
I don't know. This issue has been addressed in fiction many times before, by Phillip K. Dick, among others, and even by the writers of The Simpsons. It's a conundrum, and I'm not so sure the law as we know it could deal with it.
AS
I think you're probably right... and yeah, when cloning happens, it's going to become quite interesting, indeed.
Thanks again for jumping in here... Huntsman and you have both given me some new perspectives on this.
