> On 27 Sep 2015, at 10:32 PM, Bruce Kellett <[email protected]> wrote: > >> On 25/09/2015 2:58 pm, Stathis Papaioannou wrote: >>> On 24 Sep 2015, at 6:07 PM, Bruce Kellett <[email protected]> wrote: >>>> On 25/09/2015 12:53 am, Stathis Papaioannou wrote: >>>> You present "closest continuer theory" as if it is obviously correct, and >>>> it is not. In any case, even granting the theory, why should the causal or >>>> physical connection make a difference? I've sometimes encountered this >>>> claim in these discussions but it is just ad hoc. >>> The theory is no more ad hoc than any other theory of personal identity. >>> When we seek to encapsulate an intuitive notion in language, any attempt >>> could be criticized as being ad hoc, so that charge is of no substance. >> It's ad hoc to say that if one copy differed from the original by 1% and the >> other copy by 1.001%, then the 1% copy is the continuation of the original >> and the other copy a different person. It sounds like something made up by >> legislators rather than philosophers, like an arbitrary cutoff for a speed >> limit. > > That is a contrived situation. The full theory has a defined metric (which > may or may not be a personal preference) by which one quantifies the > differences between copies (or potential other persons). That metric will > specify when differences become too small to be significant -- we then claim > ties for 'closest' continuer. There need be no conundrums if one does things > sensibly. > >> If you can't "encapsulate an intuitive concept in language" then you should >> state that, or conclude that there is something wrong with the intuitive >> notion. > > I suggest you tell this to Plato and suggest that he withdraws his > Theaetetus! The majority of philosophy (100% for linguistic philosophers) is > the attempt to make the intuitive concepts of language more precise -- to > encapsulate an intuitive notion is language.
But sometimes the conclusion is that the intuitive concept is wrong or useless. Derek Parfit came to essentially that conclusion about personal identity by considering duplication thought experiments. >> But my more substantive dispute was with your assertion that if a copy arose >> through random processes then it wouldn't really count as a continuation of >> the original. That's like saying that if car fell together from parts in a >> junkyard stirred up by a whirlwind it wouldn't really be a car - even though >> it functioned exactly like a car made in a factory. > > That analogy does not fly. Your random car is not the continuation of any > previously existing car: the random person appearing in the Andromeda galaxy > is not a continuation of me, no mater how similar it is to me on the relevant > metric. That random object may well be a person, just as the car in your junk > yard is a car -- it is just that neither is the continuer of any existing > person or car. The person's psychological continuity would be preserved. I consider I would survive if my psychological continuity was preserved without my physical continuity necessarily being preserved; in fact, the only reason I endeavour to have my physical continuity preserved is because it's the easiest way to preserve psychological continuity. Preservation of physical continuity without psychological continuity, for example if someone has a head injury that wipes out all cognitive function, is not something anyone aspires to. >> ........ >>> >>>> The Copernican Principle in conjunction with the observation that the >>>> universe is uniform in all directions is enough. >>> No, that is not enough. The Copernician principle is not a law of physics >>> -- or of anything else, for that matter. It is a useful heuristic, nothing >>> more. The so-called "uniformity of the universe (isotropy and homogeneity)" >>> is also nothing more than a useful approximation that can be used only on >>> the largest scales -- when you average over all local structure. Such >>> arguments have no force against the position I am arguing. >> >> Your argument misses the point, which is that IF the universe is infinite >> and uniform THEN there would be infinite copies of you and everything you >> see, and you could not know which of these copies you were at any moment. > > This is false. It is like the old probability problem of how many people you > need in a room for there to be a greater than 50% probability of two having > the same birthday. The answer, iirc, is 23. However, the number required in > order for there to be a greater than 50% chance for there to be a person who > has the same birthday as you do is substantially greater. The necessity for > copies does not imply that you are copied. > > Think of it this way. Take the Tegmark Type I multiverse and suppose that you > are unique (no copies anywhere. Or better, that our life-friendly universe is > unique). Then, by time reversal invariance, continue that universe back to > the big bang to recover the initial state. Is that initial state impossible? > Or any less likely than any other potential initial state? Duplicates there > will be in the multiverse, but there is no necessity that you, or our > observed O-region, be duplicated. It's possible that there are no copies of you, but it seems implausible. There would have to be infinite copies of other things, but not you. What makes the non-copied configurations special? > And even if you are duplicated as Tegmark suggests, so that there are many > copies far outside our O-region, or even our particle horizon, then there is > absolutely no possibilitiy of any interaction between these copies, so their > existence or non-existence can have no effect on you, so they are irrelevant > -- in principle, not just FAPP. They cannot interact with each other, but they are psychologically continuous with each other. You can't know which copy is generating your mind. If you were implemented in two parallel simulations on two computers running in lockstep, you would not be able to interact with your copy, and you would not be able to know which computer you were being implemented on. Alternatively, it could be said that your mind was distributed across the two computers. If one of the computers were switched off, your mind would continue running, unable to notice that anything unusual had happened. > The situation then is just like that with the disjoint worlds of the MWI in > QM: the separate worlds are disjoint -- non interacting -- so their existence > has no bearing on you or your future. In fact, Susskind and others have > identified Tegmark's level I multiverse with the MWI of quantum mechanics. I > think this identification is nonsense, but the relevance of the potential > copies is the same in both cases -- zero! It is not zero if you could be any of the copies. >> There is reason to believe that in fact the universe is infinite and >> uniform; but if it is not, which is possible, the conditional argument still >> stands. So, do you think you would experience the world differently if there >> were infinite copies of you and of every possible variation of you? > > No. Not that I believe that there are such copies, but even if there were, > they would be of zero consequence for anything whatsoever. What would it mean for probability if your mind were spread over infinite copies? -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
