And yet no atom in your body is likely to remain from the person you were a decade ago. Are you the same xenophon41?
Erl’s “destructive copy” example is actually occuring to all of us all the time, just not instantaneously. What percentage of particles need to change before xenophon41[sup]0[/sup] gives way to xenophon41[sup]1[/sup]?
Yeah, and they get even wackier when you make up nonsense and put it in their mouths. Sorry if that sounds snippy; it’s just that there’s a lot of New-Age babbling about the quantum-mechanical nature of consciousness, and will few exceptions, it’s coming from people who know jack about QM.
Since the scenario you propose is in no way absurd from the point of view of physics (whereas time travel, on the other hand, would violate causality and bring the Universe crashing down around our ears) I don’t think any physicist would object.
I think I have a better picture now what you’re getting at with the OP. Since I’m not the exact same person I was a millisecond ago, why do I still consider myself to be the same entity? I think the answer is that it’s because I posses the memory of the moment before. From that point of view, then, any exact copy of me would possess those memories, and thus they would all be equally “me.”
And, for some reason, I don’t find that at all disturbing or contradictory. Perhaps I’m missing an important consequence?
Podkayne, I thought it was rather clear that 1) I was making a scientist strawman to pick on about “teleportation is impossible so why even consider it” and 2) I did this because of the response just like yours about time travel. Perhaps noting that your response is almost exactly like the “strawman” I explained you might not be so snippy 
FTR I have little to do with QM in this thread, except that I explicitly required parallel scanning to avoid some messiness that might arise from there thanks to our strawman scientists who are, by most appearances, not here. Why did you bring it up?
Apart from that, I have no problem with you stating that you only seem to be the same person to yourself. This, then, makes identity to be not “real” but a mere appearance. I believe this is part of a nominalist stance. Nothing wrong with that It does nicely resolve this question, as well, though it brings up a few others. No big deal, I don’t feel like discussing much apart from this topic in here unless someone else brings it up.
Not quite a nominalist stance. I’d like to scratch that from the record, please.
Spiritus: I understand that my body is continually exchanging individual atoms, that my cells are dying and being replaced, and that this process means I am, in the most real sense, not the man I was 10 years ago. I contend, though, that this process is merely a part of the continuity of my existence. As you admit, there is never any instantaneous replacement of all of my atoms.
Ten years ago (to pick an arbitrary starting point), xenophon41[sup]0[/sup] was at one end of a thread of experience which has led to this moment, where xenophon41[sup]0.74659694737[/sup] taps on a keyboard at work instead of resolving an invoicing problem. If at the very moment I was xenophon41[sup]0[/sup], erl had zapped a copy of me into existence, there would have been a guy exactly like me out there somewhere, who might just as well have been me, except that he wouldn’t have been me. And he might now be arguing with me in this thread as xenophon41[sup]0.587674638[/sup]. Or as xenophon41.1. Or as xonopheme67[sup]1[/sup]. In any case, he would have followed his own thread of experience which would include the gradual replacement of all his component atoms, and any copy made of him would not be him, just some other guy like him.
No two equals are the same!
heh.
OK, xen, fair enough: change is an inherent part of existence, and identity. Doesn’t that leave you in a “bald man problem” state, though? What if I (destructive scanned) all of your parts but one little particle? etc…
Another way to look at it:
Suppose a non-destructive scan is made of me in 1990. In 1993, the copy of me is pulled over by police and asked about an unpaid parking fine from 1988. The copy says, quite truthfully, “That wasn’t me, officer, but I remember getting the ticket.”
erl: Which part of me did you forget to [destructive] scan? (It’s not important to me anymore, of course, but it might be a big loss for the new guy!)
I’ve often wondered if subatomic particles are really exactly alike in every respect. There might be, for simplicity sake, TWO different “colors” of neutrons yet they function the same way. Not unlike isotopes of chemical elements function they same way (eg Carbon-14 functions exactly the same as Carbon-12, yet contains some more neutron mass).
well that is off of the track of the op.
In example one (DESTRUCTIVE SCANNING) you mention a “time-lag”…This is interesting…what if the time lag were not fractions of a second but rather years…do you “exist” in a computer databank ready to “remake” you? I’d say you don’t exist! If you fail to exist (even for a microsecond) your existance has ended. The reconstuction would make a new “you-like” person.
As far as Harmless Scanning goes…The person that is created is a “you-like” person but not “you”. But since your continuity remains, the scannee is you.
Why does that matter? You have posited that identity is inherent in the specific component particles. Whether those particles are changed instantaneously or gradually over time has no bearing on the question, “when do you stop being the man you were?”
On the other hand, if changing particles is merely a part of the “continuity of your existence”, then changing all of them at once should have no more impact than changing them individually over time.
Either the preservation of distinct component parts is necessary for identity or it is not. You initially said “yes”, now you appear to be saying “no, except if the change happens really really fast.” I confess that I am unable to imagine why speed of replacement should be a factor.
No more than you could say the same if you were not dupllicated. The truthful answer is, “it’s a fair cop.” Then they build a bridge out of you.
Blast my inexact language…
I’ve posited that identity is inherent in the entity, not in its component particles. I’ve further posited that the continuity of existence of a specific entity alters but maintains its identity.
First let’s look at the case of an inanimate object. I copy the thing in every last detail, using erl’s destructive scanner. On a purely utilitarian basis, the copy I make might as well be the same object, but it is not. I destroyed the original. (Had I used the non-destructive scanner®, presumably I’d have both the original and the copy, and thus I would have empirical proof that the copy was a distinct and separate entity from the original.) If I systematically replaced each component of the original atom by atom, I would still have only one object, with a unique identity.
If we add biological functions and consciousness to the object being copied, I don’t see why I should then revise my opinion regarding identity. Simply because all biological creatures change over time does not mean they lose their identity with each incremental change.
It’s the difference between alteration of an entity and substitution of one entity for another.
I disagree. My duplicate was not in existence in 1988, although his synaptic patterns hold a somewhat inaccurate and constantly revisionable recording of the events which happened to me, the original, in that year. If the cop pulled me over, the best I could say would be “Good bust, but I’ve changed since then.”
Uh, I have a feeling I just got whooshed…
A DUCK.
[sup]Preeeeecisely.[/sup]
[/quote]
OK, just had to get that out of my system.
Indeed… so change the scanner to not be parallel but to do it at the rate of 1.000 X 10[sup]23[/sup] [sup]atom[/sup]/[sub]sec[/sub]. (knew I had to squeeze a “23” in there somewhere, dintcha) What then?
Or better yet, make the scan-transmit-replicate project instantaneous. What then?.. I have a feeling that xenophon is approaching xeno rapidly. When do I get to hear that motion is impossible?
No doubt. But is it the same object with the same identity?? That, my friend, is the question.
And I think that’s the essential question. MHO is that, no matter how quickly the substitution of the discrete particles is accomplished, the identity of the object, while it may have been altered, has not been substituted.
Even if you turn it into a newt…
Um, okay. What do you mean by “entity”? How can it be differentiated from “identity”?
I’m afraid I really do not understand what you mean by this. What feature of an “entity” enjoys continuity of existence? What features of “identity” are altered?
Why? I understand that this is your opinion. I am just having a hard time understanding where you find “identity” in this example if it is not in the particles. What if the object breaks in two pieces, sits broken for millenia, and is then put back together in a manner which is perfectly seamless. Is it the same object as before? Is it the same object as the broken half(s)?
Really? And how does this differ from the destructive replication? What is that other than a systematic atom-by-atom replacement?
I don’t either.
Right. Now why is the word “incremental” necessary in that sentence?
Rate of particle change makes that difference? Exactly how fast must an entity change to be “substituted” rather than “altered”? What pecentage of particles must be “substituted” before entity[sup]0[/sup] becomes entity[sup]1[/sup]?
I disagree. You and your duplicate have exactly the same claim to have existed in 1988. You have both “changed since then” without sacrificing identity.
Yep. Erl and I will now smile and feel smugly superior . . .
[sub]okay, okay. It’s from Monty Python and the Holy Grail[/sub]
So much for my smug superiority. If only I typed faster.
xeno, you might have answered this responding to my last post anyway, but please tell me exactly what the difference between substitution and alteration is when discussing particle makeup of an entitiy. Surely you are not tying identity to physical location in space? If every particle in your body is replaced instantaneously by an exact duplicate, would you have been altered or substituted?
See previous ill-considered post. :embarassed: I admit that I can’t put my finger on a specific rate of particle replacement that should be considered substitution of an entity rather than a process of change. (sorry, erl; I rushed through the setup to get to the punchline)
continued…
erl:
Yup. Where does this particular consciousness go? If I walk into a duplicator, which side do I walk out of? Now that’s a funky question, and at the core of what you’re rassling with. And I’m damned if I know.
I think there’s no difference. If it walks like an andros and quacks like an andros, and thinks it’s an andros, and remembers being an andros, I think it’s a safe bet it’ll be able to cash my paychecks.
Eh. check this out.
Perhaps we were all created by that wonderful machine five minutes ago with all our “memories” of “past experiences” simply designed by that wonderful machine. 
According to [url=“http://www.merriam-webster.com/”]Merriam Webster[/url:
entity
Etymology: Medieval Latin entitas, from Latin ent-, ens existing thing, from coined present participle of esse to be
identity
Etymology: Middle French identité, from Late Latin identitat-, identitas, probably from Latin identidem repeatedly, contraction of idem et idem, literally, same and same
I take the word “entity” to mean a material object which has objectively verifiable existence, while “identity” is the assertion that said object has [had] continuous existence over time. (Hence, my assertion regarding identity being tied to continuity.)
Mmm, I don’t think so. But I am tying it to separation from all other similar or exact objects, so spatial position does have something to do with it. Identity itself isn’t dependent on maintaining a location, but rather a distinction.
However, I definitely think consciousness is tied to frame of reference, so as soon as you create an exactly similar consciousness and give it a separate frame of reference, it necessarily gains a separate identity.
Whether that’s a distinction without a difference is for better minds than mine to determine…
How so? I said nothing about your scenario being the least bit implausible according to the laws of physics.
You could have said, “Ignore any potential conflicts with the laws of physics and assume this is possible,” but instead, it seems to me, you took a cheap dig at physicsts, radically oversimplifying arguments against the possibility of time-travel and thus implying that physicists are wont to reject an idea, not because it contradicts the laws of nature as we understand them, but because the idea strikes them as “absurd.” I hope you can see how a physicists, who stake their professional reputations on observation, experiment, and mathematics over emotion and intuiton, would take exception to such a characterization.
However, it doesn’t seem to be bothering anyone else, so I’m probably just being thin-skinned and I should drop it, because the rest of the discussion is much more interesting.
[/quote]
FTR I have little to do with QM in this thread, except that I explicitly required parallel scanning to avoid some messiness that might arise from there thanks to our strawman scientists who are, by most appearances, not here. Why did you bring it up?
[/quote]
I was just trying to figure out what a layman would think that a physicist might object to in your scenario. As I said before, certain non-physicists (and a few physcists, too) are enchanted with the idea of a quantum mechanical unpinning of consciousness, and I guessed that maybe that’s what you were getting at, and was trying to say that this wasn’t a problem.
I don’t think that’s what I said. If a copy of me says, “I am Podkayne,” and possesses all my memories, habits of thought, personality, etc., copied so perfectly that no method of questioning could discern the difference, then how is it that the copy only seems to be me? I have no problem with acknowledging that the experiment has created two of me, equal in me-ness. (I see on preview that this is basically what andros is saying.)
I should say that I consider “me” to be the sum of my experience, memories, brain chemistry, etc. So perhaps it’s better to say that I don’t consider identity to be an illusion, unless consciousness itself is an illusion (which it may be, I suppose.)
My mind keeps drifting to the possiblity of trickery. Say some aliens just invented a personality out of thin air and downloaded it into my brain. What does that do to my identity–is my identity then less valid because my memories are false?
Maybe it’s better to consider the identity of an inatimate object that has been exactly duplicated, and leave consciousness out of it?
Yes, except it wasn’t five minutes ago, it was Last Thursday.