Thanks for the clarification. However when you say:
Suppose I am one of twins, but I don’t know which twin I am. But I know that twin 1 will be hit in face in next 1 minute. In this case I am in the situation of so called indexical uncertainty and my best guess is that I have 50 per cent probability of being twin 1 and thus 50 per cent probability being hit in the future. After I will be hit, I will know with 100 per cent probability that I am twin 1.
This is really not unique to twins. Suppose I choose two strangers and tell them that I will flip a coin and punch one or the other of them in the face in one minute, depending on the outcome of the coin toss. Assuming the strangers stick around, they will be in the same position as the two twins in your example. So, I don’t really see how this tells us anything interesting about identity, twins or copies.
Also, considering the first two of your three cases of copies, i.e. past copies and mirror copies, it seems to me that if I make a nondestructive copy of a person, the two will be mirror copies only for an instant; once the copy process completes and the two “wake up” (presuming that copying is done from an unconscious state), the two copies will immediately begin diverging based on different stimuli, etc., and will therefore become instances of case 1 (past copies). So, from a practical standpoint, there can be no instances of case 2 for any meaningful duration of time (that is to say, for enough time to interact with the copies).
I would like to clarify my position: Identity is complex social adaptation and it is directly connected with hard problem of consciousness. So we can’t finally solve any identity paradox on our current level of knowledge.
Indexical uncertainty in case of twins is a trick which may be used to skip identity problem. It doesn’t prove that twins are identical. It just makes it not important.
So it doesn’t prove that twins are the same. It may work for very different people as long as everyone don’t know who is who. But it could be reasonable guide to make decisions in the situations where many my copies exist (including uploading, quantum multiverse statistic etc)
But it is not the only principle. Another one is “conservative approach”—that is we should try to preserve as much identity as possible as we don’t know what is identity.
Identity is complex social adaptation and it is directly connected with hard problem of consciousness.
I agree that identity is directly connected with the hard problem of consciousness. That identity is a social adaptation seems plausible (to me) but not certain.
So we can’t finally solve any identity paradox on our current level of knowledge.
It seems to me that, per mwengler’s observation, we already have past copies (your category number 1); identical twins are past copies that branched shortly after conception. Past copies, it seems to me, do not share a common identity and are distinct people with distinct conscious experiences. I’m not sure that I see any identity paradoxes involving past copies.
Current, mirror copies (your category number 2), cannot exist in a conscious state for any meaningful amount of time (except perhaps as EMs where the hosting environment ensures that they have identical stimuli, are kept in sync from a simulation standpoint, etc.), so mirror copies can be ignored, it seems to me.
Future copies (your category number 3) do seem to have some paradoxes (or at least they are unclear to me). Specifically,
if I know that I am going to be non-destructively copied in five minutes, should I care more about one future copy than I do the other? I suspect that I should not.
If I know that I am going to be copied but the original will be destroyed in the process, should this concern me? It seems like, per #1, it should not. But, somehow, I don’t think that I’d be very eager to go through with a destructive copy process.
How can it be that the identity of a person and his/her future copy is the same (which seems plausible), but two past copies have distinct identities? It seems like personal identity should be transitive.
So it seems to me that future copies are paradoxical. And of course future copies will matter if/when uploading becomes possible, so we will eventually need to resolve (or accept) the paradoxes.
I agree that only future copies are paradoxical. And most paradoxes are about are decisions. So we could try to solve them as decision theory problems.
If identity is something real, it should have properties, like transitivness, and copy paradoxes should have definite solutions.
But is identity is only illusion or social agreement we could redefine it according our needs.
One of the possible approaches to identity problem is to ask why identity exist at all? What are its roots?
One of its roots is in evolutionary psychology. In early human societies each person should be able to know what will be consequences of his actions (pain, paternity, meal) and who knows what in his tribe. It required very strong feeling of personal identity and ability to distinguish it. It gave rise to names and ability to distinguish individuality of other tribe members as well as idea that they are the same tribe members everyday. (Some people change their identity during initiation rituals by the way).
But for different living beings identity could evolve differently—for viruses it include all viruses with the same code for example.
It resulted that our culture and our brain have very strong built-in instruments to distinguish identity—of me and my family members. Unfortunately, than we come to the age of uploading, these old built-in structures start to protest our new ways of breeding and survival. And here appear most paradoxes.
But this doesn’t solve identity problem, as evolution may be able to harness some kind of natural process, which provide physical basis for identity, like qualia, causality, continuity, you name it. It had harnessed many other physical effects before for its goals, like light, sound, chemistry etc.
(Another solution to identity origins is that God created souls as basis of identity and controls their identity every moment, but we could not take such idea seriously in rationalist forum).
Thanks for the clarification. However when you say:
This is really not unique to twins. Suppose I choose two strangers and tell them that I will flip a coin and punch one or the other of them in the face in one minute, depending on the outcome of the coin toss. Assuming the strangers stick around, they will be in the same position as the two twins in your example. So, I don’t really see how this tells us anything interesting about identity, twins or copies.
Also, considering the first two of your three cases of copies, i.e. past copies and mirror copies, it seems to me that if I make a nondestructive copy of a person, the two will be mirror copies only for an instant; once the copy process completes and the two “wake up” (presuming that copying is done from an unconscious state), the two copies will immediately begin diverging based on different stimuli, etc., and will therefore become instances of case 1 (past copies). So, from a practical standpoint, there can be no instances of case 2 for any meaningful duration of time (that is to say, for enough time to interact with the copies).
I would like to clarify my position: Identity is complex social adaptation and it is directly connected with hard problem of consciousness. So we can’t finally solve any identity paradox on our current level of knowledge.
Indexical uncertainty in case of twins is a trick which may be used to skip identity problem. It doesn’t prove that twins are identical. It just makes it not important.
So it doesn’t prove that twins are the same. It may work for very different people as long as everyone don’t know who is who. But it could be reasonable guide to make decisions in the situations where many my copies exist (including uploading, quantum multiverse statistic etc)
But it is not the only principle. Another one is “conservative approach”—that is we should try to preserve as much identity as possible as we don’t know what is identity.
I agree that identity is directly connected with the hard problem of consciousness. That identity is a social adaptation seems plausible (to me) but not certain.
It seems to me that, per mwengler’s observation, we already have past copies (your category number 1); identical twins are past copies that branched shortly after conception. Past copies, it seems to me, do not share a common identity and are distinct people with distinct conscious experiences. I’m not sure that I see any identity paradoxes involving past copies.
Current, mirror copies (your category number 2), cannot exist in a conscious state for any meaningful amount of time (except perhaps as EMs where the hosting environment ensures that they have identical stimuli, are kept in sync from a simulation standpoint, etc.), so mirror copies can be ignored, it seems to me.
Future copies (your category number 3) do seem to have some paradoxes (or at least they are unclear to me). Specifically,
if I know that I am going to be non-destructively copied in five minutes, should I care more about one future copy than I do the other? I suspect that I should not.
If I know that I am going to be copied but the original will be destroyed in the process, should this concern me? It seems like, per #1, it should not. But, somehow, I don’t think that I’d be very eager to go through with a destructive copy process.
How can it be that the identity of a person and his/her future copy is the same (which seems plausible), but two past copies have distinct identities? It seems like personal identity should be transitive.
So it seems to me that future copies are paradoxical. And of course future copies will matter if/when uploading becomes possible, so we will eventually need to resolve (or accept) the paradoxes.
I agree that only future copies are paradoxical. And most paradoxes are about are decisions. So we could try to solve them as decision theory problems.
If identity is something real, it should have properties, like transitivness, and copy paradoxes should have definite solutions.
But is identity is only illusion or social agreement we could redefine it according our needs.
One of the possible approaches to identity problem is to ask why identity exist at all? What are its roots?
One of its roots is in evolutionary psychology. In early human societies each person should be able to know what will be consequences of his actions (pain, paternity, meal) and who knows what in his tribe. It required very strong feeling of personal identity and ability to distinguish it. It gave rise to names and ability to distinguish individuality of other tribe members as well as idea that they are the same tribe members everyday. (Some people change their identity during initiation rituals by the way). But for different living beings identity could evolve differently—for viruses it include all viruses with the same code for example.
It resulted that our culture and our brain have very strong built-in instruments to distinguish identity—of me and my family members. Unfortunately, than we come to the age of uploading, these old built-in structures start to protest our new ways of breeding and survival. And here appear most paradoxes.
But this doesn’t solve identity problem, as evolution may be able to harness some kind of natural process, which provide physical basis for identity, like qualia, causality, continuity, you name it. It had harnessed many other physical effects before for its goals, like light, sound, chemistry etc.
(Another solution to identity origins is that God created souls as basis of identity and controls their identity every moment, but we could not take such idea seriously in rationalist forum).