Re: A calculus of personal identity

From: Stathis Papaioannou <>
Date: Mon, 26 Jun 2006 22:28:45 +1000

Bruno Marchal writes (quoting SP):
> > Of course, it is not possible for a third person observer to be > > certain about first person mental states, and this would apply to our > > teleportee: he may feel as if he is the same person as he was prior to > > the procedure, but he might be wrong.> > If he is a zombie, by definition he feels nothing.
I am assuming here he is not a zombie, that he has a memory of what he felt like pre-teleportation, but that he may be wrong about this. When we remember our past, we are doing something analogous to what we do when we look at someone else's account of their first person experience and try to imagine what it must have been like to have that experience. Memories of our past are generally more vivid and hold more information than writing, film etc., but there may come a time when people directly share memories with each other as easily as they now share mp3 files.
> > The flaw in this argument is that the same considerations hold if he > > had travelled by train: he may look and feel like the same person, > > have all the appropriate memories, and so on, but how does he know > > that the original didn't die during the journey, to be replaced by a > > copy as would have happened had he teleported?> > Here I agree and see what you mean. That is why those saying "yes" to > the doctor eventually should understand we do die at each instant. Like > we do "split" or differentiate at each instant without any means to > know that directly.> > > If there is some sense in which a person's identity might be lost > > despite his physical and mental attributes being apparently preserved > > (and I'm not sure the idea is even coherent), there is no reason for > > nature to waste effort evolving and maintaining such an > > identity-conservation system, because it cannot make any difference to > > behaviour.> > I would agree if I was believing in Nature. As a scientist I am neutral > about the existence of nature, but assuming comp "Nature", like > "matter" should not be reified.
Can you think of any findings in evolutionary biology which count as evidence either for or against the existence of a material world? Of course, most scientists, like most people, assume there is a material world out there, but this is not a premiss on the basis of which scientific theories stand or fall.
> >> Comp itself cannot be proved but what can be proved is that IF comp is> >> correct then comp cannot be proved, necessarily. So we have, somehow,> >> to be open to non-comp beliefs.> >>> >> Put in another way: if you survive when saying YES to the doctor, you> >> have to respect those who say NO to the doctor (unless you have bad> >> intentions of course or are ignorant).> >> > The falseness of comp (or functionalism) does not necessarily mean > > duplication would be a death sentence.> > > You are right but the reverse is true: if duplication (at any level) is > a death sentence, then comp is wrong.> But you a right, for example we could survive duplication because God > is so good and so clever as being able to duplicate our non-comp-soul > and link it to the genuine digital brain copies ....
I don't understand why you say "if duplication (at any level) is a death sentence, then comp is wrong". There must be a *minimal* level of duplication fidelity below which consciousness/intelligence is not preserved, no? Or are you using "duplication" to mean perfect duplication, in which case how can we have different levels of perfection?
> >> Parfit has not see this, and that is why he dares to qualify (a bit> >> provocatively I would say) his identity theory as a reductionist> >> theory, or "the reductionist theory". With comp (when made explicit)> >> Parfit's theory is mainly correct except on two points:> >>> >> 1) What I have just said: the theory is not reductionist---It is the> >> contrary: it provides (by diagonalizations!) many vaccine against many> >> form of reductionism. After dinner ;) I could even go as far as to say> >> it gives a path toward that Unconceivable Freedom described by some> >> mystic like Vimalakirti!> >> 2) We are type, not token. There is no physical token. (with comp).> >> Parfit thinks we are token. I have not the Parfit under the hand, I> >> will give you the pages later. I don't think there are any > >> mathematical> >> token either. It looks like Parfit makes us token for avoiding> >> immortality at the start.> >> > You may be referring to chapter 99 of "Reasons and Persons". A "token" > > is a particular instantiation of a person, while a "type" is the set > > of related instantiations (these terms are actually attributed to the > > philosopher Bernard Williams). As I read him, Parfit says that we are > > each token, but the significance we attach to our lives and those of > > others we care about must be attached to a type rather than a > > particular token. Thus, in destructive teleportation, a token is > > destroyed, but the type survives.> > I think this makes Parfit non coherent. If I am a token, and if only > the type survive, I don't survive.
This is an important point, perhaps *the* most important point in Parfit's book. The problem lies with the pronouns, and with the psychology on which these pronouns are based. Evolution and grammarians never anticipated the kind of duplication experiments we have been discussing! If I undergo destructive teleportation, how should I describe what happens? If I say, "I am destroyed in Brussels" then how can I say that I survive the procedure? If I don't say "I am destroyed in Brussels" then who *is* destroyed as part of the destructive scanning? So when I say, "I am destroyed in Brussels and reconstituted in Moscow", what I really mean is, "a certain instantiation, or token, identifying as Stathis-in-Brussels is destroyed, then another instantiation identifying as Stathis-in-Moscow is created, such that the two instantiations taken together identify as a single individual, or type, persisting through time, Stathis-in-Brussels-then-Moscow." It can only be made unambiguous by introducing the third person POV because the "I" refers to different tokens/instantiations depending on the stage of the teleportation process: the idea that there is a single "I" persisting through time is an illusion, involving looking at one's future or past as if from the 1st person POV when in fact the 1st person POV is necessarily tied to a single token/instantiation. This is why I say that "I" live only transiently when I am interested in being rigorous, while in everyday life I use the pronoun "I" to mean what most people mean by it, and what my human-standard psychological makeup tells me it means.
Stathis Papaioannou
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Received on Mon Jun 26 2006 - 08:29:49 PDT

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