X-Message-Number: 21035 Date: Sat, 01 Feb 2003 20:43:52 -0700 From: Mike Perry <> Subject: "Sameness" and Graph Theory, Relevance and Language Thomas Donaldson suggests that my notion of "sameness" via continuers can be described in terms of mathematical graph theory--a good suggestion with which I agree. He further suggests that the appropriate graph in this case is a tree, in which descendants or "continuers" are accessible from earlier, "ancestor" nodes but not vice versa. Actually (and this is elaborated in my book, though without the mathematical jargon) the most general structure that I allow (ignoring certain issues such as forgetting), is not a tree but a (rooted) directed, acyclic graph. The different branches need not remain separate but can join back, though one branch cannot loop back and join itself at an earlier point. Thus I allow that different persons could actually fuse into one; the one individual would feel it was the "same" as (= a continuer of) two or more, originally separate individuals. (For reasons I discuss in the book, though, I don't think such fusions will dominate in the future when we have ascended beyond the human level, but fissioning will be more common.) So, if you have nodes A and B, you may have a (directed) path from A to B. If you do, then you do not also have a path from B to A, except in the trivial case of A=B. So you say that B is a continuer of A but not vice versa--continuer is not continuee. Once again, the relation of "sameness" (continuer *or* continuee) satisfies two of the three properties of equivalence: A is the same as A (reflexivity); if A is the same as B then B is the same as A (symmetry). But the third, transitivity, can still fail: if A is the same as B and B is the same as C then it is not necessarily true that A is the same as C. (Another point, fairly minor, is that the graph is "rooted" in the sense that I allow a "null being" with no consciousness, that every node can be considered to be a continuer of; this occasionally has uses.) All this seems reasonable to me. I would say I am the "same" person as ten years ago, though not identical in all respects, and the lack of being identical is not simply reducible to an equivalence relation. If a copy of me had been created ten years ago, but then had lived a separate life, I would not want to say I am the "same" person as that presently existing, onetime copy, even though we once were the same. One of us is not a more developed version of the other but each would have things the other lacks. It is conceivable, however, that we could agree to pool our memories and form one individual again, that is to say, fuse. Then (because, in this case, A is the same as A) we *would* be once again the same individual. I can see a lot of difficulties with the "pooling" of memories so that an individual would feel that he/she had been simultaneously doing different things in different places with full, parallel consciousnesses. But I think it could probably be handled, for any who might be interested, through a notion similar to the "record fields" concept where one record in a database contains several "fields" each with a different snippet of information. Still the idea of fusion doesn't have much appeal--I certainly don't hope for or advocate all becoming one consciousness. A flower garden is best if you have a variety of different flowers and not just one, even if big and fancy. To restate and add to previous comments about the relevance of this to cryonics: the notion of continuer is important, I feel, because it offers a possible concept of reanimation that is not dependent on conserving the original material. This includes the case of some but not all the original material being retained. It could be important if, in the future, there is a tradeoff between a protocol that would better conserve the matter but put the information more at risk, versus the other way around. And already we see at least a limited form of such a tradeoff, in the neuro (head only) versus whole body option. Proponents of neuro in particular argue that at least neuros are easier to maintain and can be relocated more easily in case of emergency, which could be important in the possibly turbulent times ahead of us. (Another argument, and more controversial, is that neuro protocols can and do give the brain a better treatment.) Some comments seem in order on the issue of language when we are talking about "sameness." The notion of continuer denies that persons who are considered the "same" must be the same physically, as chunks of matter. But then persons are not like rare coins or antiques, where the original material is all-important and copies, however exact, just won't do. They are, instead, more like books, which are reasonably regarded as bodies of information rather than specific copies. The analogy can be sharpened if we think of a person as like a written history that is being kept up-to-date through successive editions. A new edition might be formed either by adding material at the end of an existing volume, or by issuing a new volume from time to time, as in a set of encyclopedia yearbooks. A particular edition of the history may exist in many physical copies. The copies are not identical but, unless you are a book collector, the nature of the differences is unimportant. The whole history may have a title, such as "Joe Schmoe's Events Digest" or JSED. Different editions will be distinct from one another, though only in a certain, restricted way; all will still be JSED. If copyright policies are lenient, it is even possible that different companies will start issuing their own updated editions, so you will have the fissioning of JSED into more than one entity, or in other words, more definitely different JSEDs. Later, if the companies decide to join forces, you could have (re)fusion--and so on. Are you a specific chunk of matter or an ongoing, information-based process? Are you your bits or your atoms (or maybe something in-between or something else entirely)? These are points worth pondering, and the answers arrived at do have a bearing on our attempts at extending our lives. I think too that there is an important sense in which the answers *cannot* be decided by scientific experiment, since they depend on preferences or taste or what one considers important. Still it seems likely that one or more of the various theories will prove far more workable and rewarding, at least for the long haul, than others equally consistent and not disprovable. I'm betting on the informational approach, and less concerned with alternatives that depend on specific collections of particles. Mike Perry Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=21035