I have been on vacation so I have a large backlog of messages to read! But they are very interesting and full of challenging ideas. I find this list to be one of the best I have ever been on in terms both of fearlessly exploring difficult areas and also remaining cordial and polite.
I am trying to understand Lee Corbin's idea about duplicates as selves better. I can understand seeing exact, synchronized duplicates as selves (such as two computers running the same simulated individual in lock-step). But when they begin to diverge I understand that Lee still sees them as (in some sense) "himself" and one copy would in fact sacrifice to benefit a diverged copy just as much(?) as to benefit its own body. Is this right? What I would ask is, is there a limit to this? Is this common-self-ness a matter of degree, or is it all-or-none? Is there some degree of divergence after which a copy might be somewhat reluctant to continue to view its brother copy as being exactly equivalent to itself? For example, what if someone were an identical twin? In some sense they are duplicates at the moment of conception who then begin to diverge. This seems to be different from the copies we discuss merely in degree of divergence, not in kind. Would it be reasonable to argue that an identical twin "should" view his brother as himself? And what about the possibility of creating non-identical copies? Perhaps our copying machine is imperfect and the products are not quite the same as the original. They are very close, perhaps so close that only extremely detailed inspection can detect the differences. Or perhaps they are not really so close at all and the copies in fact bear little resemblance to their originals. How does the potential existence of such imperfect copying machines affect the notion that one should view copies as selves? If imperfect or diverged copies are to be considered as lesser-degree selves, is there an absolute rule which applies, an objective reality which governs the extent to which two different individuals are the same "self", or is it ultimately a matter of taste and opinion for the individuals involved to make the determination? Is this something that reasonable people can disagree on, or is there an objective truth about it that they should ultimately come to agreement on if they work at it long enough? Hal Finney